Gcal 3.6

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Gcal

This file documents gcal, a program for calculating and printing calendars.

Gcal displays hybrid and proleptic Julian and Gregorian calendar sheets, respectively, for one month, three months or a whole year. It also displays eternal holiday lists for many countries around the globe, and features a very powerful creation of fixed date lists that can be used for reminding purposes. Gcal can calculate various astronomical data and times of the Sun and the Moon for at pleasure any location, precisely enough for most civil purposes. Gcal supports some other calendar systems, for example the Chinese calendar, the Hebrew calendar and the civil Islamic calendar, too.

This is Edition 3.6 of Gcal, an Extended Calendar Program,
24 June 2000, for the 3.6 version of the GNU implementation
of cal and calendar.

Any suggestions, improvements, extensions, bug reports, donations, proposals for contract work, and so forth are welcome! Please send them directly to my eMail address esken@gmx.net. If you like my work, I'd appreciate a postcard from you!

———————————–oOO      \\\_”/      OOo—————————————
Thomas Esken               O     (/o-o\)     O  eMail: esken@gmx.net
Im Hagenfeld 84                 ((  ^  ))       Phone: +49 251 232585
D-48147 Muenster; Germany    \____) ~ (____/    MotD : 2old2live, 2young2die

Appendices

Indices

--- The Detailed Node Listing ---

Invoking Gcal

Command line arguments

Options

Commands

Fixed Dates

Resource file

Further date part attributes

Gcal Utilities

Regular Expressions

Special Texts

Exclusions

Exclusions with date argument

Exclusions without any argument

Replacements

Replacements with date argument

Replacements with other argument

Replacements without any argument

Obsolete Special Texts

Coding Scheme


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1 Preface

The reason why I have written Gcal was mainly to have an off-line tool1 which is able to display Julian and Gregorian calendar sheets in a highly flexible and internationalized manner, fixed date lists for reminding purposes and country respectively territory specific holiday lists. At a later stage, Gcal was extended in the way to perform some basic astronomical calculations like Moon phase, moonrise, moonset and other Moon based data, sunset, sunrise, different twilight times and other Sun based data, zodiacal markers, solar and lunar eclipses, equinoxes and solstices. Other gimmicks like biorhythm calculation and the computation of a distance between two geographical point locations and their course angles (true tracks) are also done by it now, plus a lot more.

The accuracy of most of the astronomical calculations done by Gcal is low because it is really hard to perform accurate astronomical predictions more that 100 years ahead. Of course, this also has consequences for some country specific holidays which are based on such astronomical calculations. So it is really possible that some output may differ from the real astronomical date and time of the event calculated, and that by one or more minutes/hours/days. This can happen when the date of a real astronomical event occurs near around midnight. So don't be surprised! Strictly speaking, take all such astronomically based output as a more or less good approximation of the true value, but do not rely on it!

Because Gcal is not primarily designed for the purpose of having a high precision astronomical calculation tool, the world currently has to live with these limitations. But if you have C source code functions, which

and you want to grant them to the public, I would be very pleased if you would contact me so I am able to implement your result to a next release of this software.

Some words to the build-in country specific holidays now...

As you certainly know, there are several other calendar systems actually existing around the world among the Gregorian calendar. The Gregorian calendar that Gcal mainly represents as a software is only one calendar of many others, but it is that one which is most respected around the world today. Even countries which use another calendar system officially mostly respect the Gregorian calendar for civil and administrative purposes.

But when Gcal offers the ability to include holidays from a definite country into its eternal holiday list, it is possible that not all holidays are displayed which are respected in that country. One reason is that my various sources simply don't tell me about the existence of a holiday. A second reason is that the holiday is just designed or changed or removed by political or society reality during Gcal's development phase. And another reason is that the method to calculate a holiday is not build-in Gcal yet. This case is marked by a ‘#’ character behind the country name in the list of countries, which are respected by Gcal. See Calendar option --cc-holidays=cc[_tt][+...], for the above mentioned list.
The holidays of early years that are included into the eternal holiday list —i.e. those within the period AD 30 until the midth of the 20th century— are certainly not accomplishing the requirements of historians to such a list. Gcal cannot be understood as a complete and historically correct data base, and it is not designed for that purpose! This is caused by the fact that the territorial borders and names of the national structures and the settlement in earlier times was partly quite different as it is nowadays. Moreover, I am yet lacking reliable information that tells me the precise date of the introduction of a holiday in a region. Here I appeal to the historians to support me with the concrete country and culture based data if they are bothered by this fact and they want to have it removed.

Still unsupported alive and major calendar systems, respectively methods to derive country specific holidays from them, are:

Even if the list of supported countries seems to be almost complete if you compare it with the actual list of all nations existing around the world, you should note that there are still some countries missing! If you can grant me support to complete Gcal's list of respected countries, or if you would work out or have C functions which manage the missing calendar systems, I also would be very pleased about if you would contact me.

I have recorded the country specific holiday dates as good as I can, but I cannot guarantee that I did not made any mistakes while I hacked them in. So it is possible that some country specific holiday lists contain errors.

Well, if you think that I forgot to provide Gcal with the specific holidays of a/your country, or you think that a country specific holiday list is incomplete, or you think that some of the already implemented holidays are wrong, please feel free to send me a complete list of all the holidays which are celebrated in this country respectively to give me hints how to correct or to complete them!

Such a list should ideally include the following information:

The Islamic holidays inserted into the country specific holiday list are calculated arithmetically, not astronomically. This is what people call the civil Islamic lunar calendar. This type of calendar is just a rough estimate of the religious Islamic lunar calendar, which is determined quite astronomically. So don't be surprised too much if some holiday dates differ from the religious Islamic calendar about +/- 1...2 days in some years.
The main difficulty to implement the religious Islamic calendar correctly into Gcal are the several different criteria that are existing for the first sighting of the crescent Moon after a New Moon phase — that event, which defines the beginning of a new (lunar) month in the religious oriented Islamic calendar. So on the one hand, there are quite astronomically-based criteria, and on the other hand, there are also quite religiously-based criteria. Furthermore, the local predominant weather conditions, the geographical co-ordinate of the observer's location and the kind of the observance method used also affect these criteria. Moreover, to render all more difficult, I as yet do not have any reliable information that tells me which kind of criteria is used in the countries (around 60 world-wide) which respect this religious Islamic calendar. So due to all the above mentioned facts of problematic nature, this religious Islamic calendar is not included into Gcal yet.

The Chinese (and Japanese) holidays also inserted into the country specific holiday list are calculated by using that algorithm as it is used by the Purple Mountain Observatory in Nanjing to determine the astronomical lunisolar Chinese calendar. This calendar is obligatory for (the Peoples Republic of) China since 1929 and is determined annually always new. Nevertheless and strictly speaking, in the historic reality and depending on the region, the Chinese calendar, especially in the 17th and 18th century, was either calculated using this modern algorithm, or by the use of a different method, so that a different calendar structure for one and the same year was possibly calculated as result.

And last...

This manual shows the possible use of the Gcal program only briefly and deliberately renounces to present the topics that are covered by this software arranged in a novel-like style. The use of Gcal is illustrated in an exemplary manner only! A detailed description of all possible use is inexpedient here because there are simply too many of such possibilities which are caused by the existing variety of combinations of all useable modes of operation.

Furthermore, this manual does not contain detailed explanations about the calendar systems supported by Gcal, nor it can be understood as a reference-book for the basics in celestial mechanics or spherical trigonometry! A detailed discussion of the above topics is completely beyond the scope of this manual. If you are interested to learn more about these subjects, you unfortunately have to read the specific pertinent literature.

Any further errors occurring in the output of the above mentioned holiday lists and in the astronomical calculations are my own fault, and are not intended to offend members of any culture, religion or profession!


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2 Gcal Introduction

Apart from the usual and well known calendar functions like the output of a month or a year calendar sheet, or the output of an eternal holiday list, Gcal, the Gregorian calendar program of the Free Software Foundation, offers the facility to display fixed dates on the day of their occurrence and to remind or inform the user about them. So it is imaginable after booting the computer or starting the work session, that the user is informed on screen or by means of electronic mail about all holidays or appointments which are observed or scheduled for that day.

The period, for which Gcal respects occurring fixed dates, may be freely selected by the user. So it is possible that Gcal displays all fixed dates which occur on tomorrow's date, the whole week, the whole month or in the whole year. Fixed dates which occur on a selected date of the year, and those that occur relative to another given date, are displayed either related to this single date only, or in listed manner starting on this date and ending on the actual date3.

There are two methods to display a preview of fixed dates4 or retrospective view of fixed dates5. On the one hand, Gcal can be started by using an option that sets the system date of the computer to the given date during the time of the program execution with the result, the program assumes the system date is set to this given date and the user can define any needed period that should be respected by an option. On the other hand, Gcal can be started with a command which forces the program to use a different year instead of the actual year, so Gcal will display all occurring fixed dates for this particular year. But this limits the user in that it disables defining any needed period by an option, because the period is always set to the whole year by default.

Gcal isn't only able to display fixed dates which are stored for a concrete date, e.g. ‘Fixed date on 1st December 1995’, rather than fixed dates occurring periodically again and again. So it is possible to define repeated events like ‘This fixed date occurs every day in May 1995’ or ‘Every 15th November in any years’. These fixed date definitions are stored in resource files and whenever Gcal is started, an option to evaluate the necessary resource files can be given.

Once the user has set his/her preferred command line arguments for querying the fixed dates data base, it is possible to store them in a response file or shell script file. A response file contains all arguments delivered to Gcal, but unlike a shell script file, such a response file isn't executable; it is only a pool of command line arguments which can be preloaded if needed. A shell script file can be started and calls Gcal directly with all arguments stored in it and all arguments which are given further in the command line.

A list of all usable command line arguments and their descriptions can be found in the next chapter, which helps one to use Gcal in the most efficient and productive way possible. After it follows the description how to use the eternal holiday list, and in the succeeding chapter, how to use the fixed date list. Comprehensive explanations respectively summaries and tables to definite details or themes from other disciplines can be found in the numerous appendices.


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3 Invoking gcal

Gcal is a command line oriented program. It is usually called from the shell6 and processes given arguments that are options and commands. Options must be given before commands, i.e. you must call Gcal like this:

     
gcal [ [option...] [%date] [@file...] ] [command]

If Gcal is started without any options or commands, a calendar of the current month is displayed. If the calendar of a definite year is wanted, the year must be fully specified, e.g. ‘gcal 94’ displays a year calendar of the year 94, not of the year 1994.

If two arguments are given in the command part, the first argument denotes the month, and the second argument denotes the year. In case any incorrect commands are given running Gcal, the program will use internal defaults.

In the English program version, Gcal assumes the Gregorian Reformation has occurred in 1752 on the 3rd of September. See Genesis of the Gregorian Calendar, and Aspects in Internationalization, for further details.


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3.1 Command line arguments

This section describes all command line arguments processed by Gcal. Four different types of command line arguments exists. One important type of arguments are the options which control how Gcal behaves. Other types of arguments are the %date and the @file options. The %date option sets the period Gcal shall work on to any starting date; the @file option preloads options and commands from a response file. The most important arguments are the commands which control the periods Gcal respects.

An option is defined by a leading switch character; either the ‘-’ (dash) or the ‘/’ (slash) character for traditional short-style options, or ‘--’ for mnemonic long-style options; a command may not have a leading switch character. Options7 must be given before commands!

Depending on operating system and used shell, some of the arguments and texts given in command line must be quoted by ‘"’ or ‘'’ characters respectively protected or depreciated by a ‘\’ character to avoid expansion by the shell.

Here is an incomplete list of characters which must potentially be protected:

(’, ‘)’, ‘<’, ‘>’, ‘[’, ‘]’, ‘{’, ‘}’, ‘\’, ‘|’, ‘$’, ‘@’, ‘!’, ‘&’, ‘~’, ‘"’, ‘'’, ‘`’, ‘;


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3.1.1 Options

The options processed by Gcal can be grouped into four major option classes. The options of the common option class are the standard options all GNU software should implement at least partially. The global option class contains options which affect the program output. The options of the calendar option class control the calendar layout, and the options of the fixed date option class control the fixed date layout and intensity.

Gcal supports both short-style options and GNU long-style options. Traditional short-style options are indicated by a single switch character, and trailed by the option character itself and perhaps a modifier or an argument. The most single character options8 can be composed into a single command line word: -Ax is equivalent to -A -x. GNU long-style options are indicated with ‘--’, and trailed by the mnemonic option name itself and perhaps an argument. Long-style options and their arguments may be abbreviated if done unambiguously. When a long-style option takes an argument, connect the option name and the argument with ‘=’.

Brackets ([ and ]) indicate in the following tables, that an option takes an optional argument. The ‘|’ character is used to separate several arguments from each other.

Gcal processes the GNU long-style options in a special, non-standard way. There are five different types of long-style options:

  1. --foo
    Enables option --foo.
  2. --foo=bar
    Enables option --foo with the required argument bar.
  3. --foo[=bar[|...|bar]]
    Option --foo may have one bar argument. If no argument list is given, any argument can be given to this option. If an argument list is given, exactly one bar argument may be selected from the given list. If there is no argument chosen in this case, the first bar argument of the argument list is preselected by default.
  4. --foo=bar|...|bar
    Option --foo requires exactly one bar argument which must be selected from the given argument list.
  5. --foo=bar|...|bar|baz
    Option --foo requires exactly one bar argument which must be selected from the given bar argument list, or the alternative baz argument.

Traditional short-style options differ as follows:

  1. -x
    Enables option -x.
  2. -x bar
    Enables option -x with the required argument bar. The bar argument may be separated by a leading whitespace character from the short-style option character x. This means, the following notations are valid for giving an argument, namely -x bar or -xbar.
  3. -x[bar|...|bar]
    Option -x may have one or more bar modifier. In this sense, modifiers are one or more characters which define a special mode of operation enabled by the -x option. A modifier may not be separated by a leading whitespace character from the short-style option character.


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3.1.1.1 Common options

-?
-h
--help
Print a short usage message listing only some few of all available options, then exit successfully.
-??
-hh
--usage[=argument]
--long-help[=argument]
Print an extended usage message listing all available options, then exit successfully. If an argument is given and it is a valid long-style option name, an extended help text related to the given long-style option name is displayed only, e.g.:
          --long-help=long-help

displays the extended help text for the long option --long-help.

If the argument only consists of the single ‘?’ character or is no valid long-style option name, a list of all valid long-style option names is displayed.

-L
--license
--copyleft
--copyright
Print the software license message, then exit successfully.
-V
--version
Print the version number and compilation options, then exit successfully.
--exit-status-help-non-zero
Set the exit state of program to 127 instead to 0, if one of the other options of the common option class is used.


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3.1.1.2 Global options

-R name
--response-file=name
Write the contents of the environment variable GCAL (see Environment Variable GCAL), and then the arguments of command line (in the given order) to file name, i.e. create response file name. See Response file, for more details.
-S name
--shell-script=name
Write the contents of the environment variable GCAL (see Environment Variable GCAL), and then the arguments of command line (in the given order) to file name, i.e. create shell script file name. An automatically created shell script file is executable and calls Gcal directly with the arguments stored in it. You may start the shell script with other command line arguments which are directed to Gcal, too.
--debug[=internal|handled|unhandled|all|abort]
Display some debug information.
--debug=internal
Display informational texts if program internal maxima are reached or other conditions occurred, respectively.
--debug=handled
Like --debug=internal, additionally display the file names which can be processed respectively handled.
--debug=unhandled
Like --debug=internal, additionally display file names which cannot be processed respectively handled.
--debug=all
Like --debug=handled and --debug=unhandled together.
--debug=abort
Like --debug=all and abort program with an error code if the file name cannot be handled or other unmanageable conditions occurred, respectively. See Error Codes.

-p
--pager
Enables either an external pager or a simple, internal pager. If an environment variable PAGER is set, its contents will be used for detecting the external pager program. See Environment Variable PAGER, for more information.

If no PAGER environment variable is set or if its contents is invalid, Gcal tries to use the less pager; if this program cannot be found during scanning the PATH environment variable, Gcal tries to use the more pager, if this program cannot be found, the pg pager in the same way9. See Environment Variable PATH.

If all these actions fail, Gcal will use its simple, built-in pager. If the internal pager is used, Gcal detects the number of lines shown before it prompts and waits for user input by using these methods:

  1. Gcal respects the values set in the environment variables GCAL_LINES and GCAL_COLUMNS. See Environment Variable GCAL_LINES, and Environment Variable GCAL_COLUMNS, for further information.
  2. If above action fails, Gcal respects the values set in the environment variables LINES and COLUMNS. See Environment Variable LINES, and Environment Variable COLUMNS, for more details.
  3. If above action fails, Gcal respects the values set in the termcap10 file which refers to the terminal used (see Environment Variable TERM). This step is only done on systems which support the use of Termcap by default.

    On MS-DOS, OS/2 and some other operating systems, Gcal uses a system dependent low-level function and respects the reported values.

  4. If all above actions have failed, Gcal uses default values11.

-H yes
--force-highlighting
--highlighting=yes
If the output of the program is redirected12 or piped13, the highlighting sequences are not automatically converted into the according marking characters, they remain unchanged. This option takes no effect if the output of the program is sent by means of electronic mail. See Global option --mail[=address].
-H no
--disable-highlighting
--highlighting=no
Disable highlighting sequence / marking character pairs of current day, holiday or text explicitly.
-H text
--highlighting=text
Set highlighting sequence / marking character pairs explicitly. In this sense, highlighting sequences are control character sequences which cause a color or intensity switch in output text. Typical control character sequences are the ANSI escape sequences which have a leading escape character, and trailing more characters that define the type of the ANSI escape sequence. In this sense, marking characters are single, printable characters which lead and trail the output text.

The text argument must be a (‘:’) colon-separated text which is structured in this way: seq1_start:seq1_end:seq2_start:seq2_end. The first sequence is used for highlighting/marking an actual day, the second for a holiday. The sequences must be given in form of a sequence pair; seq?_start enables the highlighting/marking, seq?_end disables it. Only two sequence pairs will be processed, others are ignored. Either highlighting sequence pairs or marking character pairs may be defined, i.e. using them both in a mixed couple is not permitted!

For example:

-H \x20:\x20:\x1:# respectively
--highlighting=\x20:\x20:\x1:#
marks the actual day like ‘\x20actual date\x2014 and the holiday date like ‘\x1holiday date# using the given marking characters.
-H \x1b[34;42m:\x1b[0;40m or
-H \033[34;42m:\033[0;40m or
-H \E[34;42m:\E[0;40m
defines a starting ANSI escape highlighting sequence ‘\x1b[34;42m used for actual day and ending ANSI escape highlighting sequence ‘\x1b[0;40m with no given highlighting sequence for holidays, so default highlighting sequences for holidays are used (non-given entries are always skipped). Please note the last abstract of this text part which informs you more detailed of this context. See Environment Variable GCALANSI, too.

Control code definitions may contain any printable characters. Non-printable characters may be encoded in octal or hexadecimal notation. The abbreviation ‘\E’ directly encodes the escape character (octal \033 respectively hexadecimal \x1B).

A character can be encoded octal by typing ‘\nnn’ (backslash-octal digit(s)), where n must be a valid octal digit (0...7). Normally, three octal digits must be given. If the octal character code consists of one or two octal digits, leading zeroes must be added, except the case, where the encoded octal character is given at last in the single sequence.

A character can be encoded hexadecimal by typing ‘\xnn’ (backslash-x hexadecimal digit(s)), where n must be a valid hexadecimal digit (0...9A...Fa...f). Normally, two hexadecimal digits must be given. If the hexadecimal character code consists of one hexadecimal digit, a leading zero must be added, except the case, where the encoded hexadecimal character is given at last in the single sequence.

If the sequence separator character, thus the ‘:’ (colon) character itself, is used as a marking character, it must be encoded either octal by \072 or hexadecimal by \x3A.

If the C Preprocessor symbol USE_PAGER was defined and the output of the program is redirected or used in a pipeline, the highlighting sequences are automatically converted into the according marking characters; if USE_PAGER was not defined, they remain untouched.

Incomplete or non-given highlighting sequences will be replaced by internal default ANSI escape highlighting sequences if a GCALANSI environment variable is defined; otherwise completely replaced by their according marking characters. See Environment Variable GCALANSI.

--mail[=address]
Send Gcal's output via mail15 program to the given address, e.g.:
          --mail=esken@gmx.net

If no address is given, Gcal tries to send the eMail by using the following methods:

  1. If an environment variable MAILTO is defined and set, the eMail is send to the address which is listed in this environment variable. See Environment Variable MAILTO, for more information.
  2. If above action fails, and if an environment variable USER is defined and set, the eMail is send to the address which is listed in this environment variable. See Environment Variable USER, for more information.
  3. If above action fails, and if an environment variable LOGNAME is defined and set, the eMail is send to the address which is listed in this environment variable. See Environment Variable LOGNAME, for more information.
  4. If all above actions have failed, no eMail is send.

Generally, Gcal does not send electronic Mails whose message body is empty! An informational message will be shown on the standard error channel if this case occurs.

All highlighting sequences produced by Gcal itself are always disabled respectively automatically converted into the according marking characters if an eMail must be send; no matter if the --force-highlighting option was given or not. This behavior of Gcal is an imperative necessity, because it is possible that the mail program cannot perform the mailing correctly. Please pay attention in this context to the further explanations concerning the limitations of the text part of a resource file line (see Text part of a line).

If an environment variable MAILPROG is defined and set, its contents will be used as the program name of the mailer instead of the standard name mail. See Environment Variable MAILPROG, for more information.


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3.1.1.3 Calendar options

-n|N[-]
--holiday-list[=long|short]
--descending-holiday-list[=long|short]
Display the eternal holiday list. By default, there are no entries in the eternal holiday list. You have to choose country specific holidays or holidays from other calendar systems to provide the eternal holiday list with entries. See Eternal Holidays, and Calendar option --cc-holidays=cc[+...], for additional information.
-n
--holiday-list=long
Display all holidays of eternal holiday list —this means, all legal holidays and all further memorial days— sorted in ascending order.
-n-
--descending-holiday-list=long
Display all holidays of eternal holiday list —this means, all legal holidays and all further memorial days— sorted in descending order.
-N
--holiday-list=short
Display legal holidays only of eternal holiday list, sorted in ascending order.
-N-
--descending-holiday-list=short
Display legal holidays only of eternal holiday list, sorted in descending order.

-G
--suppress-holiday-list-separator
Suppress displaying of the blank line which is always leading an eternal holiday list.
-X
--exclude-holiday-list-title
Suppress the title text line of the eternal holiday list.
--astronomical-holidays
Provide the eternal holiday list additionally with some astronomical data, and that the Full and New Moon phases, waning and waxing Half Moon phases, solar and lunar eclipses, and the solstices and equinoxes. See Calendar option --time-offset=argument, how to change the timezone respectively base time for which the astronomical data is calculated.
--bahai-holidays
Provide the eternal holiday list additionally with Bahá'ì holidays (only for dates after AD 1843).
--celtic-holidays
Provide the eternal holiday list additionally with Celtic holidays. See Calendar option --time-offset=argument, how to change the timezone for which the Celtic holidays are calculated.
--chinese-flexible-holidays
Provide the eternal holiday list additionally with Chinese holidays, that are determined in a flexible manner (only for dates after AD 1644). See Calendar option --time-offset=argument, how to change the timezone for which the Chinese holidays are calculated in a flexible manner. See Preface, for further details.
--chinese-holidays
Provide the eternal holiday list additionally with Chinese holidays (only for dates after AD 1644). For dates until AD 1928 all computations done are depending fixed on Beijing local time, for later dates fixed on the timezone GMT-8. See Preface, for further details.
--christian-holidays
Provide the eternal holiday list additionally with Christian holidays.
--hebrew-holidays
Provide the eternal holiday list additionally with Hebrew holidays.
--islamic-civil-holidays
Provide the eternal holiday list additionally with Islamic holidays (only for dates after AD 621), that are based on the civil Islamic calendar. See Preface, for further details.
--japanese-flexible-holidays
Provide the eternal holiday list additionally with Japanese holidays, that are determined in a flexible manner (only for dates after AD 1644). See Calendar option --time-offset=argument, how to change the timezone for which the Japanese holidays are calculated in a flexible manner.
--japanese-holidays
Provide the eternal holiday list additionally with Japanese holidays (only for dates after AD 1644). For dates until AD 1887 all computations done are depending fixed on Beijing local time, for later dates fixed on the timezone GMT-9.
--multicultural-new-year-holidays
Provide the eternal holiday list additionally with multicultural New Year holidays. See Calendar option --time-offset=argument, how to change the timezone for which the multicultural New Year holidays are calculated.
--orthodox-new-holidays
Provide the eternal holiday list additionally with Orthodox new calendar holidays, and it is assumed that the Gregorian Reformation has occurred from 10th till 22nd March 1924. See Calendar option --orthodox-calendar, for further details.
--orthodox-old-holidays
Provide the eternal holiday list additionally with Orthodox new calendar holidays, and it is assumed that the Gregorian Reformation has occurred from 10th till 22nd March 1924. See Calendar option --orthodox-calendar, for further details.
--persian-jalaali-holidays
Provide the eternal holiday list additionally with Persian holidays (only for dates after AD 621), which are based on the Persian Jalaali calendar. All computations done are depending on the timezone GMT-3.5.
--zodiacal-marker-holidays
Provide the eternal holiday list additionally with zodiacal marker holidays, i.e. the dates when the Sun enters a zodiac sign or when the Sun reaches the turning-point in the zodiac sign. See Calendar option --time-offset=argument, how to change the timezone for which the zodiacal marker holidays are calculated.
-q cc[_tt][+...]
--cc-holidays=cc[_tt][+...]
Provide the eternal holiday list additionally with country specific holidays. Furthermore, all additionally highlighted days of the eternal holiday list are highlighted in the calendar sheets, too.

The cc argument is a two-letter country code as defined by the ISO-316616 like ‘BE’ for Belgium or ‘ES’ for Spain. See the pertinent literature for more details.

In some cases, such a country code may be trailed by a two-letter territory code tt for better specification, which is separated by a ‘_’ character from the country code.

You can use more than one country code cc[_tt] by connecting them with a ‘+’ character, e.g.:

--cc-holidays=be+Fr+IT resp.,
-q be+Fr+IT

includes all the country specific holidays given in the preceding argument into the eternal holiday list, i.e. Belgian, French and Italian holidays.

Actually, Gcal respects the following country codes, at which countries marked by a ‘#’ character have only an incomplete recording of holidays:

AD
Andorra
AE
United Arab Emirates
AF
Afghanistan
AG
Antigua and Barbuda
AI
Anguilla
AL
Albania
AM
Armenia
AN_BO
Netherlands Antilles/Bonaire
AN_CU
Netherlands Antilles/Curaçao
AN_MA
Netherlands Antilles/St Maarten
AN_SA
Netherlands Antilles/Saba and Statia
AO
Angola #
AR
Argentina
AS
American Samoa
AT
Austria
AU_CT
Australia/Canberra
AU_NT
Australia/Northern Territory
AU_QU
Australia/Queensland
AU_SA
Australia/Southern Australia
AU_SW
Australia/New South Wales
AU_TA
Australia/Tasmania
AU_VI
Australia/Victoria
AU_WA
Australia/Western Australia
AW
Aruba
AZ
Azerbaijan
BA
Bosnia-Herzegovina
BB
Barbados
BD
Bangladesh #
BE
Belgium
BF
Burkina Faso
BG
Bulgaria
BH
Bahrain
BI
Burundi #
BJ
Benin #
BM
Bermuda
BN
Brunei
BO
Bolivia
BR
Brazil
BS
Bahamas
BT
Bhutan #
BV
Bouvet Island
BW
Botswana
BY
Belarus
BZ
Belize
CA_AL
Canada/Alberta
CA_BC
Canada/British Columbia
CA_MA
Canada/Manitoba
CA_NB
Canada/New Brunswick
CA_NF
Canada/Newfoundland and Labrador
CA_NS
Canada/Nova Scotia
CA_NW
Canada/Nordwest Territories
CA_ON
Canada/Ontario
CA_PE
Canada/Prince Edward Island
CA_QU
Canada/Québec
CA_SA
Canada/Saskatchewan
CA_YU
Canada/Yukon
CC
Cocos Islands (Keeling)
CD
Democratic Republic of Congo #
CF
Central African Republic #
CG
Republic of Congo #
CH_AG
Switzerland/Aargau
CH_AI
Switzerland/Appenzell Innerrhoden
CH_AR
Switzerland/Appenzell Ausserrhoden
CH_BE
Switzerland/Bern
CH_BL
Switzerland/Basel-Land
CH_BS
Switzerland/Basel-Stadt
CH_FR
Switzerland/Fribourg
CH_GE
Switzerland/Genève
CH_GL
Switzerland/Glarus
CH_GR
Switzerland/Graubünden
CH_JU
Switzerland/Jura
CH_LU
Switzerland/Luzern
CH_NE
Switzerland/Neuchâtel
CH_NW
Switzerland/Nidwalden
CH_OW
Switzerland/Obwalden
CH_SG
Switzerland/St Gallen
CH_SH
Switzerland/Schaffhausen
CH_SO
Switzerland/Solothurn
CH_SZ
Switzerland/Schwyz
CH_TG
Switzerland/Thurgau
CH_TI
Switzerland/Ticino
CH_UR
Switzerland/Uri
CH_VD
Switzerland/Vaud
CH_VS
Switzerland/Valais
CH_ZG
Switzerland/Zug
CH_ZH
Switzerland/Zürich
CI
Côte d'Ivoire
CK
Cook Islands
CL
Chile
CM
Cameroon
CN
China
CO
Colombia
CR
Costa Rica
CU
Cuba
CV
Cape Verde
CX
Christmas Islands
CY
Cyprus
CZ
Czech Republic
DE_BB
Germany/Brandenburg
DE_BE
Germany/Berlin
DE_BW
Germany/Baden-Württemberg
DE_BY
Germany/Bavaria
DE_HB
Germany/Bremen
DE_HE
Germany/Hesse
DE_HH
Germany/Hamburg
DE_MV
Germany/Mecklenburg-West Pomerania
DE_NI
Germany/Lower Saxony
DE_NW
Germany/North Rhine-Westphalia
DE_RP
Germany/Rhineland Palatinate
DE_SH
Germany/Schleswig-Holstein
DE_SL
Germany/Saar
DE_SN
Germany/Saxony
DE_ST
Germany/Saxony-Anhalt
DE_TH
Germany/Thuringia
DJ
Djibouti
DK
Denmark
DM
Dominica
DO
Dominican Republic
DZ
Algeria
EC
Ecuador
EE
Estonia
EG
Egypt
EH
Western Sahara
ER
Eritrea
ES
Spain
ET
Ethiopia
FI
Finland
FJ
Fiji #
FK
Falkland Islands (Malvinas)
FM
Federated States of Micronesia
FO
Faroes
FR
France
GA
Gabon #
GB_EN
Great Britain/England and Wales
GB_NI
Great Britain/Northern Ireland
GB_SL
Great Britain/Scotland
GD
Grenada
GE
Georgia
GF
French Guiana
GH
Ghana
GI
Gibraltar
GL
Greenland
GM
Gambia
GN
Guinea
GP
Guadeloupe
GQ
Equatorial Guinea
GR
Greece
GS
South Georgia and South Sandwich Islands
GT
Guatemala
GU
Guam
GW
Guinea-Bissau #
GY
Guyana #
HK
Hong Kong
HM
Heard and Mc Donald Islands
HN
Honduras
HR
Croatia
HT
Haiti
HU
Hungary
ID
Indonesia #
IE
Ireland
IL
Israel
IN
India #
IQ
Iraq
IR
Islamic Republic of Iran
IS
Iceland
IT
Italy
JM
Jamaica
JO
Jordan
JP
Japan
KE
Kenya #
KG
Kyrgyzstan
KH
Cambodia #
KI
Kiribati #
KM
Comoros
KN
St Kitts and Nevis
KP
Democratic People's Republic of Korea #
KR
Republic of Korea
KW
Kuwait
KY
Cayman Islands
KZ
Kazakhstan
LA
Laos People's Democratic Republic #
LB
Lebanon
LC
St Lucia
LI
Liechtenstein
LK
Sri Lanka #
LR
Liberia
LS
Lesotho
LT
Lithuania
LU
Luxembourg
LV
Latvia
LY
Libyan Arab Jamahiriya (Libya)
MA
Morocco
MC
Monaco
MD
Republic of Moldova
MG
Madagascar #
MH
Marshall Islands
MK
Former Yugoslav Republic of Macedonia
ML
Mali
MN
Mongolia #
MO
Macau
MP
Northern Marian Islands (Saipan)
MQ
Martinique
MR
Mauritania
MS
Montserrat
MT
Malta
MU
Mauritius
MV
Maldives
MW
Malawi
MX
Mexico
MY
Malaysia #
MZ
Mozambique
NA
Namibia
NC
New Caledonia
NE
Niger
NF
Norfolk Islands
NG
Nigeria
NI
Nicaragua
NL
Netherlands
NM
Myanmar (Burma) #
NO
Norway
NP
Nepal #
NR
Nauru
NU
Niue
NZ
New Zealand
OM
Oman
PA
Panama
PE
Peru
PF
French Polynesia
PG
Papua New Guinea
PH
Philippines
PK
Pakistan
PL
Poland
PM
Saint-Pierre and Miquelon
PN
Pitcairn
PR
Puerto Rico
PT
Portugal
PW
Palau
PY
Paraguay
QA
Qatar
RE
Réunion
RO
Romania
RU
Russian Federation
RW
Rwanda
SA
Saudi Arabia
SB
Solomon Islands
SC
Seychellen
SD
Sudan
SE
Sweden
SG
Singapore #
SH
St Helena
SI
Slovenia
SJ
Svalbard and Jan Mayen Islands
SK
Slovakia
SL
Sierra Leone
SM
San Marino
SN
Senegal
SO
Somalia
SR
Suriname #
ST
Sao Tomé and Principe
SV
El Salvador
SY
Syrian Arab Republic (Syria)
SZ
Swaziland
TC
Turks and Caicos Islands
TD
Chad
TG
Togo #
TH
Thailand #
TJ
Tajikistan
TK
Tokelau
TM
Turkmenistan
TN
Tunisia
TO
Tonga
TR
Turkey
TT
Trinidad and Tobago #
TV
Tuvalu
TW
Taiwan
TZ
Tanzania
UA
Ukraine
UG
Uganda
US_AK
United States/Alaska
US_AL
United States/Alabama
US_AR
United States/Arkansas
US_AZ
United States/Arizona
US_CA
United States/California
US_CO
United States/Colorado
US_CT
United States/Connecticut
US_DC
United States/District of Columbia
US_DE
United States/Delaware
US_FL
United States/Florida
US_GA
United States/Georgia
US_HI
United States/Hawaii
US_IA
United States/Iowa
US_ID
United States/Idaho
US_IL
United States/Illinois
US_IN
United States/Indiana
US_KS
United States/Kansas
US_KY
United States/Kentucky
US_LA
United States/Louisiana
US_MA
United States/Massachusetts
US_MD
United States/Maryland
US_ME
United States/Maine
US_MI
United States/Michigan
US_MN
United States/Minnesota
US_MO
United States/Missouri
US_MS
United States/Mississippi
US_MT
United States/Montana
US_NC
United States/North Carolina
US_ND
United States/North Dakota
US_NE
United States/Nebraska
US_NH
United States/New Hampshire
US_NJ
United States/New Jersey
US_NM
United States/New Mexico
US_NV
United States/Nevada
US_NY
United States/New York
US_OH
United States/Ohio
US_OK
United States/Oklahoma
US_OR
United States/Oregon
US_PA
United States/Pennsylvania
US_RI
United States/Rhode Island
US_SC
United States/South Carolina
US_SD
United States/South Dakota
US_TN
United States/Tennessee
US_TX
United States/Texas
US_UT
United States/Utah
US_VA
United States/Virginia
US_VT
United States/Vermont
US_WA
United States/Washington
US_WI
United States/Wisconsin
US_WV
United States/West Virginia
US_WY
United States/Wyoming
UY
Uruguay
UZ
Uzbekistan
VC
St Vincent and Grenadines
VE
Venezuela
VG
British Virgin Islands
VI
U.S. Virgin Islands
VN
Viet Nam
VU
Vanuatu
WF
Wallis and Futuna Islands
WS
Samoa
YE
Yemen
YT
Mayotte
YU
Serbia and Montenegro
ZA
South Africa
ZM
Zambia
ZW
Zimbabwe

--bahai-months
Provide the eternal holiday list additionally with the starting dates of the common and leap months, as they result from the Bahá'ì calendar. See Calendar option --bahai-holidays, for further details.
--chinese-flexible-months
Provide the eternal holiday list additionally with the starting dates of the common and leap months, as they result from the Chinese calendar, that is determined in a flexible manner. See Calendar option --chinese-flexible-holidays, for further details.
--chinese-months
Provide the eternal holiday list additionally with the starting dates of the common and leap months, as they result from the Chinese calendar. See Calendar option --chinese-holidays, for further details.
--coptic-months
Provide the eternal holiday list additionally with the starting dates of the common and leap months, as they result from the Coptic calendar (only for dates after AD 283).
--ethiopic-months
Provide the eternal holiday list additionally with the starting dates of the common and leap months, as they result from the Ethiopic calendar.
--french-revolutionary-months
Provide the eternal holiday list additionally with the starting dates of the common and leap months, as they result from the French Revolutionary calendar (only for dates after AD 1791).
--hebrew-months
Provide the eternal holiday list additionally with the starting dates of the common and leap months, as they result from the Hebrew calendar.
--indian-civil-months
Provide the eternal holiday list additionally with the starting dates of the common and leap months, as they result from the civil Indian calendar (only for dates after AD 1956).
--islamic-civil-months
Provide the eternal holiday list additionally with the starting dates of the common and leap months, as they result from the civil Islamic calendar. See Calendar option --islamic-civil-holidays, for further details.
--japanese-flexible-months
Provide the eternal holiday list additionally with the starting dates of the common and leap months, as they result from the Japanese calendar, that is determined in a flexible manner. See Calendar option --japanese-flexible-holidays, for further details.
--japanese-months
Provide the eternal holiday list additionally with the starting dates of the common and leap months, as they result from the Japanese calendar. See Calendar option --japanese-holidays, for further details.
--old-armenic-months
Provide the eternal holiday list additionally with the starting dates of the common and leap months, as they result from the Old-Armenic calendar (only for dates after AD 551).
--old-egyptic-months
Provide the eternal holiday list additionally with the starting dates of the common and leap months, as they result from the Old-Egyptic calendar.
--persian-jalaali-months
Provide the eternal holiday list additionally with the starting dates of the common and leap months, as they result from the Persian Jalaali calendar. See Calendar option --persian-jalaali-holidays, for further details.
-i[-]
--type=special|standard
To obtain the standard calendar format17, either start Gcal omitting the -i[-] option because it is set by default, Aspects in Internationalization, or start Gcal with the -i- respectively --type=standard option:
          

$ gcal -i- -| -| September 1994 -| Su Mo Tu We Th Fr Sa -| 1 2 3 -| 4 5 6 7 8 9 10 -| 11 12 13 14 15 16 17 -| 18 19 20 21 22 23 24 -| 25 26 27 28 29 30

To obtain the special calendar format, start Gcal with the -i respectively --type=special option:

          

$ gcal -i -| -| September 1994 -| -| Sunday 4 11 18 25 -| Monday 5 12 19 26 -| Tuesday 6 13 20 27 -| Wednesday 7 14 21 28 -| Thursday 1 8 15 22 29 -| Friday 2 9 16 23 30 -| Saturday 3 10 17 24


-O
--orthodox-calendar
Use the leap year rule as used by the Eastern Orthodox churches.

Without specifying the --orthodox-calendar option, Gcal is unable to display Gregorian years later than 2799 in the correct way for the Eastern churches, because they use a different scheme for calculating the leap years. The method for computing leap years within the common Gregorian calendar, which Gcal uses by default, is as follows:

A leap year is any year which number can be divided by 4 without a remainder, and years ending in hundreds are no leap years unless they are divisible by 400.

But the Eastern Orthodox churches compute leap years within the Gregorian calendar by using another rule:

A leap year is any year which number can be divided by 4 without a remainder, and years ending in hundreds are leap years, if a remainder of 2 or 6 occurs when such a year is divided by 9.

The first difference therefore occurs in the year 2800 which is a leap year in the common Gregorian calendar, but an ordinary year only in the calendar as used by the Eastern Orthodox churches.

-K
--with-week-number
Provide the calendar sheet with week numbers. See Calendar option --starting-day=argument, Calendar option --iso-week-number=yes|no, and Aspects in Internationalization, for further details.
--iso-week-number=yes|no
Determine the type of week numbers which are used in the calendar sheet, in the fixed date list and by the %date actual date modifier. See Calendar option --starting-day=argument, and Aspects in Internationalization, for more details.
--iso-week-number=yes
The methods of the ISO-8601:1988 are used for detecting week numbers; this means a week starts on Mondays, and the first week of a year is the one which includes the first Thursday; equivalently, the one which includes the 4th January. This method is called ISO week number in the further context. If the starting day of the week is not set to Monday, the week numbers are not represented correctly in most cases. If you use this option, you should take care of setting Monday as the starting day of the week!
--iso-week-number=no
Weeks start on the respective starting day of the week, and the days in a new year that are preceding the first starting day of the week are in the last week of the previous year, respectively in week zero of the new year. This method is called standard week number in the further context.

-u
--suppress-calendar
Suppress output of calendar sheet explicitly.
-b number
--blocks=number
Set number of calendar sheet blocks (valid arguments: 1|2|3|4|6|12). The default number for the standard calendar format is -b4 respectively --blocks=4, and for the special calendar format -b 3 respectively --blocks=3. If this option is found, the program sees that a year calendar output is desired!
-b 1
--blocks=1
Displays one block with twelve months at a time.
-b 2
--blocks=2
Displays two blocks with six months at a time.
-b 3
--blocks=3
Displays three blocks with four months at a time.
-b 4
--blocks=4
Displays four blocks with three months at a time.
-b 6
--blocks=6
Displays six blocks with two months at a time.
-b 12
--blocks=12
Displays twelve blocks with one month at a time.

-j[b]
--calendar-dates=special|both
Use alternative date format in calendar sheet instead of the default standard format which displays the days of month in consecutive manner.
-j
--calendar-dates=special
Display the calendar sheet by using the special date format. This means, the days of year are displayed in consecutive manner instead of the days of month.
-jb
--calendar-dates=both
Display the calendar sheet by using both the standard date format and special date format.

-jn[b]
--holiday-dates=special|both
Use alternative date format in eternal holiday list instead of the default standard format which displays the days of month in consecutive manner. See Calendar option --holiday-list[=long|short].
-jn
--holiday-dates=special
Display the eternal holiday list by using the special date format. This means, the days of year are displayed in consecutive manner instead of the days of month.
-jnb
--holiday-dates=both
Display the eternal holiday list by using both the standard date format and special date format.

-jc[b]
--fixed-dates=special|both
Use alternative date format in fixed date list instead of the default standard format which displays the days of month in consecutive manner. See Fixed date option --list-of-fixed-dates[=short|long].
-jc
--fixed-dates=special
Display the fixed date list by using the special date format. This means, the days of year are displayed in consecutive manner instead of the days of month.
-jcb
--fixed-dates=both
Display the fixed date list by using both the standard date format and special date format.

-s argument
--starting-day=argument
Set the starting day of the week (valid argument: 0, 1...7 | today | weekday name).

For example:

          --starting-day=Sunday or
          --starting-day=7 or
          -s SUNDAY or
          -s sund or
          -sSu or
          -s 7

thus all specifies the Sunday (1==Mon, 2==Tue ... 7==Sun).

If the -s today option (or --starting-day=today) or the -s 0 option (or --starting-day=0) is given, the starting day of the week is set to the actual weekday as it is delivered by the system date. See Aspects in Internationalization, for more details.

--time-offset=argument
Change the base time of the astronomical functions (valid argument: t|@|[t|@][+|-]mmmm|hh:[mm]).

If no --time-offset=argument option is given, the astronomical data that is inserted into the eternal holiday list by the --astronomical-holidays option (see Calendar option --astronomical-holidays), and all Sun and Moon related special texts are always calculated for 0 o'clock Universal time (UTC/GMT), thus civil midnight time.

See Sun data, and Moon data, likewise Moon phase, for further information.

The argument is either the ‘t’ or the ‘@’ character —where ‘t’ means a relation to the actual local time18 and ‘@’ denotes a relation to the actual Universal time—, or one of these characters followed by a displacement value, or only a displacement value which has to be specified either by using the [+|-]mmmm format or the [+|-]hh:[mm] format. [+|-]mmmm adds respectively subtracts the specified amount of minutes mmmm from the base time value 0 o'clock Universal time (range 0...9999), while [+|-]hh:[mm] adds respectively subtracts the given amount of hours hh (range 0...99) and minutes mm (range 0...59) from the base time value 0 o'clock Universal time. The displacement value is always added to the base time value 0 o'clock Universal time in case it is specified without a +|- sign.

For example, the --time-offset=+1: option causes that while displaying eternal holiday lists and fixed date lists, the time 0 o'clock of the timezone GMT-1 (== CET) is used as the base time by the astronomical functions instead of the base time 0 o'clock Universal time (== GMT).

For example, the --time-offset=t-2: option causes that while displaying eternal holiday lists and fixed date lists, the time that is two hours earlier than the actual local time is used as the base time by the astronomical functions instead of the base time 0 o'clock Universal time (== GMT). For such a kind of relation, the term relative time offset value will be used in the further context.

--transform-year=argument
Change the base year of calendar (valid argument: -9999...[+]9999).

For example, the --transform-year=-543 option causes that while displaying calendar sheets, eternal holiday lists and fixed date lists, the year 543 BC is used as the base year of the calendar instead of the year AD 1. This results in the case that —for example— for the year 1999 (Christian era), the year number 1999 is not used in the above mentioned outputs, but the year number 2542 which is used in the western oriented Thai calendar.

Nevertheless, Gcal does not respect the --transform-year=argument option when using the actual date modifier %date (see Actual date modifier), the commands (see Commands), and the fixed date entries in a resource file (see Date part of a line). There, all references made to a definite year are always treated in the way that the year AD 1 is the base year of the calendar, so in fact it is only possible to use references based on the Christian era.

--gregorian-reform=1582|1700|1752|1753|argument
Set the period which was skipped during the Gregorian Reformation. By default, Gcal runs in the hybrid calendar mode, i.e. Gcal automatically changes from the Julian calendar system to the Gregorian calendar system if output is related to dates after the Gregorian Reformation has happened. See Aspects in Internationalization, for more details. Actually, four fixed default periods are supported, and that of the year 1582, of the year 1700, of the year 1752 and of the year 1753.

If Gcal is called with the --gregorian-reform=1582 option, it assumes the Gregorian Reformation has occurred from 5th till 14th October 1582.

If Gcal is called with the --gregorian-reform=1700 option, it assumes the Gregorian Reformation has occurred from 19th till 28th February 1700.

If Gcal is called with the --gregorian-reform=1752 option, it assumes the Gregorian Reformation has occurred from 3rd till 13th September 1752.

If Gcal is called with the --gregorian-reform=1753 option, it assumes the Gregorian Reformation has occurred from 18th till 28th February 1753.

In case another period shall be respected, it can be arranged by the option argument like ‘yyyyy,mm,first-day,last-day’. If the Gregorian Reformation has occurred for example on the 7th till the 17th April 1802, this can be arranged as follows:

          --gregorian-reform=1802,4,7,17

Gcal is able to represent so-called proleptic calendars of a definite calendar system. This means, Gcal only uses a definite calendar system during a definite period, although there was a change to another calendar system in the historic reality during this definite period. The following proleptic calendar systems are actually supported by Gcal:

Please note that it is possible to corrupt the calendars likewise the fixed date feature logically (which works correctly now for the year in which the Gregorian Reformation has occurred) if the argument of the --gregorian-reform option is not used with care.

--date-format=de|us|gb|text
Set the date format which affects the ordering and representation of a displayed date. See Aspects in Internationalization, for more details. The date format text is respected by Gcal in the eternal holiday list, in the fixed date list and the calendar sheets. Moreover, Gcal internally tries to obtain the best representation of a displayed date in case the day-of-year numbers instead of the day-of-month numbers must be displayed, or both types of numbers are used in a combined manner.

Actually, three fixed default date formats are supported, and that for German users, U.S. American users and for users in Great Britain.

If Gcal is called with the --date-format=de option,
the ‘%<2#K,  %1%>2*D%2 %<3#U %>04*Y date format text is used. This result in that a date is displayed by using the ‘ww,  dd mmm yyyy ordering, for example ‘Sa,  28 Aug 1999.

If Gcal is called with the --date-format=us option,
the ‘%<3#K, %<3#U  %1%>2&*D%2 %>04*Y date format text is used. This result in that a date is displayed by using the ‘wwwmmm  dd yyyy ordering, for example ‘Sat, Aug  28th 1999.

If Gcal is called with the --date-format=gb option,
the ‘%<3#K,  %1%>2&*D%2 %<3#U %>04*Y date format text is used. This result in that a date is displayed by using the ‘www,  dd mmm yyyy ordering, for example ‘Sat,  28th Aug 1999.

In case another format text shall be respected, this format text can either be set in the GCAL_DATE_FORMAT environment variable20, or it can be arranged by the option argument text. For example, ‘--date-format='%Y %D %>02*M ; %1(%>5u#K)%2' displays a date by using the ‘[[[y]y]y]y [d]d mm ; (wwwww) ordering, thus for example ‘1999 28 08 ; (SATUR). See Environment Variable GCAL_DATE_FORMAT, for further information.

The format text may contain on the one hand all characters which can be managed by Gcal, and on the other hand character replacement instructions and format elements which are transformed into their according values at run-time. Some format elements may have a format instruction which is called format in the further context. See Format Instruction, for the detailed description of the format instruction and its components.

A minimum date format text must contain the following format elements minimum:

The day number, one component of the month group, the year number and both components of the highlighting group.

A weekday name format element may be included optionally into the date format text. The following format elements and character replacement instructions are currently supported:

%[format]D
Day number (must be defined)
%[format]Y
Year number (must be defined)
%[format]K
Weekday name (may be defined)

Month group (exactly one member must be defined):

%[format]M
Month number
%[format]U
Month name

Highlighting group (all members must be defined and %1 must be specified before %2):

%1
Start of highlighting sequence / marking character
%2
End of highlighting sequence / marking character

Character replacement instructions:

_
Space/blank character ‘
\_
Underscore character ‘_
\%
Percent character ‘%
\\
Backslash character ‘\

See Table of Obsolete Date Formats, and Table of Obsolete Date Format Elements, for further information.

--translate-string=text
Define the country specific special character pairs which are respected or translated by a style format instruction component, respectively. See Format Instruction, for the detailed description of the format instruction and its components. The country specific special character pairs are arranged by the text option argument as a sequence of single character pairs, and that in any number and order. The upper-case representation of the country specific special character has to be specified at first, and after that its lower-case representation. Country specific special characters which do not have an upper-case resp., lower-case representation in the character set used, like e.g. the ‘ß’-character which is very usual in the German character set, are also specified as a special character pair (here: ‘ßß’), otherwise these special characters are not recognized and they are converted incorrectly by the style format instruction component. In case the lower-case representation of the country specific special character is specified at first, and after that its upper-case representation, this option does not cause any further affects to the style format instruction component; resulting, the country specific special characters specified are not recognized as such and they remain untranslated therefore.

For example, a ‘ÄäÖöÜüßß option argument causes the correct conversion of the preceding special characters in an individual date format, which has a style format instruction component, and that, how they are used by the character set used in Germany.


Previous: Calendar options, Up: Options
3.1.1.4 Fixed date options

-v argument
--date-variable=argument
Define global date variable which is visible in all referenced resource files (see Date variables). The option argument must either be a valid single date variable definition or a (‘:’) colon-connected series of definitions.

A date variable name dvar consists of a single, case-insensitive letter21. In a definition, this name is trailed by the assignment operator character ‘=’, and the numerical values of month mm (or a short, three characters month name, e.g. ‘Jan’, ‘Feb...) and day dd, this variable has to store22.

For example:

--date-variable=a=1127:c=a respectively
-v a=1127:c=a
stores the 27th November into the global date variable a and into the global date variable c.

--export-date-variables
Causes the export of local date variables from one resource file to another resource file. See Date variables, for more details.
-r argument
--text-variable=argument
Define global text variable which is visible in all referenced resource files (see Text variables). The option argument must either be a valid single text variable definition or a (‘:’) colon-connected series of definitions.

A text variable name tvar consists of the ‘$’ prefix and a single, case-insensitive letter.

A text variable is defined as follows:

Indeed, Gcal executes external commands only if the --execute-command option is given at program start-up. See Fixed date option --execute-command, for more details.

The text which appears at the right side of one of the valid assignment operator characters may reference names of already defined global text variables. These references are converted to the according textual values just before the assignment is performed by Gcal.

A global text variable is defined with an empty contents in case no text appears at the right side of one of the valid assignment operator characters.

For example:

--text-variable=$a=foo:$c=$a respectively
-r $a=foo:$c=$a
stores the ‘foo’ text into the global text variable $a and into the global text variable $c.

--text-variable=$a\:foo:$c?bar respectively
-r $a\:foo:$c?bar
stores the uninterpreted output of the foo command into the global text variable $a, and the interpreted output of the bar command into the global text variable $c.

You may depreciate the special meaning of the ‘:’ separator character —in case this character itself is needed— by placing a ‘\’ (backslash) character before it, e.g. ‘\:’. If you need the ‘\:’ characters themselves, you have to protect the ‘\’ (backslash) character by another ‘\’ (backslash) character, e.g. ‘\\:’.

You may depreciate the special meaning of the ‘$’ prefix character —in case this character itself is needed in the text— by placing a ‘\’ (backslash) character before it, e.g. ‘\$’. If you need the ‘\$’ characters themselves in the text, you have to protect the ‘\’ (backslash) character by another ‘\’ (backslash) character, e.g. ‘\\$’.

Each time a ‘_’ (underscore) character is found in argument, this character is replaced by a real ‘ ’ (space) character.

You may depreciate the special meaning of the ‘_’ (underscore) character —in case this character itself is needed— by placing a ‘\’ (backslash) character before it, e.g. ‘\_’. If you need the ‘\_’ themselves, you have to protect the ‘\’ (backslash) character by another ‘\’ (backslash) character, e.g. ‘\\_’.

--export-text-variables
Causes the export of local text variables from one resource file to another resource file. See Text variables, for more details.
--adjust-value=argument
Causes on the one hand, that the number given as argument to the --adjust-value option is used as reference altitude to calculate the rise and set times by the Sun and Moon oriented special texts. The option argument must be a rational number in range -90.0...+90.0, which declares the angle distance in decimal degrees from the center of astronomical object to the horizon. For example, you can detect the time when the center of the Sun or the Moon is 20.5 decimal degrees below the horizon if you use --adjust-value=-20.5.

And causes on the other hand, that the number that is given as argument is used as factor for computing the shadow length of a vertical pole by the Sun oriented special texts. The option argument must be a rational number in range 0.0...+90.0, which declares the shadow length. For example, you can detect the time when the shadow length of vertical pole is three and a half times longer than the shadow length that appears at astronomical noon if you use --adjust-value=3.5.

See Sun data, and Moon data, for further information.

--atmosphere=air-pressure[,temperature]
Set the base data of the Earth's atmosphere that is necessary to calculate the amount of refraction23, that is used by the Sun and Moon oriented special texts. The option argument consists of one or two rational numbers, which are separated by a ‘,’ character. The first number denotes the air pressure in millibar, and the second number specifies the air temperature in degree Celsius. The default value for the air pressure is 1013.25 millibar, and the default value for the temperature is 15.0 degree Celsius. For example, if you use --atmosphere=1010,10, you define atmospheric conditions as they are existing for an air pressure of 1010 millibar and a temperature of 10 degree Celsius. If you set an air pressure value less or equal zero, no atmospheric refraction will be respected by the Sun and Moon oriented special texts, as for example done by --atmosphere=0.

See Sun data, and Moon data, for further information.

--limit
Causes when calculating the rise and set times by the Sun oriented special texts for high latitudes, that a rise or set event which possibly occurs on a previous or next day, is not displayed as occurring on the actual day as it is done by default. At high latitudes, i.e. above the solar Arctic Circle, it is fact that no, or more than one sunrise or sunset happens during a day at definite dates of the year. As a special text basically leads in a single, atomical output, even it should result in several output in reality, Gcal puts such an event on a previous or next day. Then, data represented in this manner could be misinterpreted very easily.

The following example is used to explain this. It calculates the time the astronomical twilight ends for the location Münster, Germany, during some days in May 2000, and that with and without the --limit option in each case:

          

$ gcal %20000506 -f/dev/null -cxl4+ \ > -#'0*d1#999_%s9+5158+00738,120' -| -| Sun, May 7th 2000: 23:52 -| Mon, May 8th 2000: 23:57 -| Tue, May 9th 2000: 00:01 -| Wed, May 10th 2000: 00:06 $ gcal %20000506 -f/dev/null -cxl4+ --limit \ > -#'0*d1#999_%s9+5158+00738,120' -| -| Sun, May 7th 2000: 23:52 -| Mon, May 8th 2000: 23:57 -| Tue, May 9th 2000: **:** -| Wed, May 10th 2000: **:**

As one can see well in the above example, the output for the days since 9th May differs in that the times shown without the --limit option obviously exceeded the civil midnight time and actually cannot happen during these days, whereas no times are shown for the days since 9th May if the --limit option is used because the time circle is exceeded. Astronomically seen, it is the case that the end of the astronomical twilight is at 23:57 o'clock local time on 8th May, no end of astronomical twilight happens on 9th May because the center of the Sun's disk is always above 18 degrees (the reference altitude of the astronomical twilight) below a geometric horizon, but on 10th May at 00:01 o'clock local time, this reference altitude is passed again. Thus, the time that is detected for the 9th May has properly to be moved to the 10th May, et cetera, as it is expressed by the output that is created by using the --limit option.

See Sun data, for further information.

--cycle-end=argument
Calculates the Sun and Moon oriented special texts that are dynamical, i.e. depending on the respective clocktime, for a series of clocktimes for the current day, i.e. determination is done for any time interval that can be individually defined by the user. Gcal is always put into such a cycle mode if the --cycle-end option is given at program start-up. The argument of the --cycle-end option is syntactically according to the argument which may be given to the --time-offset option, thus t|@|[t|@][+|-]mmmm|hh:[mm]. See Calendar option --time-offset=argument, for the detailed explanation of the preceding option argument. Thus, the --cycle-end option is used to fix the ending time of the time interval, whereas the --time-offset option is implicitly used to fix the starting time of the time interval, that is 0 o'clock by default24.

If values for the time interval are given to both above mentioned options that fall short of 0 o'clock, these values are automatically set to 0 o'clock. If values for the time interval are given that exceed 23:39 o'clock, these values are automatically set to 23:59 o'clock.

The timestep value between the starting and the ending time of the time interval that is respected by Gcal is one minute by default. This value can at pleasure be changed by using the --cycle-step option. See Fixed date option --cycle-step=argument, for more details.

You should always keep in mind that the use of the cycle mode is efficient only if the current time of the time interval is also part of that resource file line that has to be evaluated in this manner. Otherwise, it is difficult to find out unobjectionably lateron when displaying the data and times, which Sun or Moon oriented value resulted in what time.

The following example shows how the topocentric elevation angle of the Sun for the location Münster, Germany, is calculated during two days in April 2000, and that for the time interval 12:00 o'clock until 12:05 o'clock local time in each case:

          

$ gcal %20000420 -Hno -f/dev/null -xdt -g::: \ > --here='0*d1#999_%ot+00+000_:_%oa+5158+00738,120' \ > --cycle-end=12:05 --time=12:00 -| -| Thu, Apr 20th 2000: +12h00': +045d58' -| Thu, Apr 20th 2000: +12h01': +046d03' -| Thu, Apr 20th 2000: +12h02': +046d07' -| Thu, Apr 20th 2000: +12h03': +046d12' -| Thu, Apr 20th 2000: +12h04': +046d17' -| Thu, Apr 20th 2000: +12h05': +046d22' -| ::: -| Fri, Apr 21st 2000: +12h00': +046d18' -| Fri, Apr 21st 2000: +12h01': +046d23' -| Fri, Apr 21st 2000: +12h02': +046d28' -| Fri, Apr 21st 2000: +12h03': +046d32' -| Fri, Apr 21st 2000: +12h04': +046d37' -| Fri, Apr 21st 2000: +12h05': +046d42'

See Sun data, and Moon data, for further information.

--cycle-step=argument
Changes the timestep value that is used between the starting and ending clocktime of the time interval, in which the Sun and Moon oriented special texts are calculated, that are dynamical, i.e. depending on the respective clocktime. See Fixed date option --cycle-end=argument, how to define such a time interval. Without the --cycle-end option, a --cycle-step option is completely ignored. It also does not enable Gcal's cycle mode. The argument of the --cycle-step option is by change syntactically according to the argument which may be given to the --time-offset option, and that relative time offset value references based on the actual local time and Universal time cannot be made, respectively. Gcal always uses the amount of the given timestep value. Thus, the template for the argument that may be given to the --cycle-step option is [+|-]mmmm|hh:[mm]. See Calendar option --time-offset=argument, for the detailed explanation of the preceding option argument.

The timestep value between the starting and the ending time of the time interval that is respected by Gcal is one minute by default.

The following example shows how the topocentric elevation angle of the Sun for the location Münster, Germany, is calculated during two days in April 2000, and that for the time interval 10:00 o'clock until 17:00 o'clock local time with a timestep value of one hour and 15 minutes in each case:

          

$ gcal %20000420 -Hno -f/dev/null -xdt -g::: \ > --here='0*d1#999_%ot+00+000_:_%o*a+5158+00738,120' \ > --cycle-end=10:00 --time=17:00 --cycle-step=1:15 -| -| Thu, Apr 20th 2000: +10h45': +38.038 -| Thu, Apr 20th 2000: +12h00': +45.962 -| Thu, Apr 20th 2000: +13h15': +49.665 -| Thu, Apr 20th 2000: +14h30': +47.882 -| Thu, Apr 20th 2000: +15h45': +41.267 -| Thu, Apr 20th 2000: +17h00': +31.633 -| ::: -| Fri, Apr 21st 2000: +10h45': +38.355 -| Fri, Apr 21st 2000: +12h00': +46.299 -| Fri, Apr 21st 2000: +13h15': +50.006 -| Fri, Apr 21st 2000: +14h30': +48.198 -| Fri, Apr 21st 2000: +15h45': +41.545 -| Fri, Apr 21st 2000: +17h00': +31.881

See Sun data, and Moon data, for further information.

--precise
The astronomical data and times that are created by the Sun and Moon oriented special texts, and the geographical data that is created by the distance and course angle oriented special text, respectively, are displayed by using a higher precision, i.e. according to the mode or style of representation and the type of special text, decimal values are displayed with more decimal places, or output of the time seconds part or the arcseconds part.

See Sun data, and Moon data, likewise Geographical distance and course angle, for further information.

--execute-command
Causes on the one hand, that shell command %![argument] special texts are executed, and not displayed textually only. See Shell command %![argument] special text, for more details. And causes on the other hand, that ‘tvar?[command] and ‘tvar:[command] text variable definitions is assigned the output of an external command, and not the text which contains the call of the external command. See Text variables, for further information.
-D argument
--filter-day=argument
Displays only those fixed dates, whose date is not excluded by the given argument. See Date part of a line, and likewise Exclusions without any argument %? special texts. The argument consists of one or more characters as used in the exclusion without any argument %? special text; but without the leading ‘%’ character in each case.

For example, it is possible to induce Gcal to display only those fixed dates from the resource file demo.rc for the whole year which are legals holidays, and moreover, Saturdays or Sundays:

          gcal -f demo.rc --year --filter-day=Rv

-P argument
--filter-period=argument
Displays only those fixed dates, whose date is not excluded by the given argument. See Date part of a line, and likewise Exclusions with date argument %?[date] special texts. The argument consists of one or more expressions as used in the exclusion with date argument %?[date] special text; but without the leading ‘%’ character in each case. You can use more than one of these %?[date] expressions by connecting them with a ‘,’ character.

For example, it is possible to induce Gcal to display only those fixed dates from the resource file demo.rc for the whole year which appear within the period of the 17th and the 20th of any month, and which appear on the 31st of any month.

          gcal -f demo.rc -y -P i00000017#00000020,i00000031#00000031

-I pattern
--filter-text=pattern
Displays only those fixed dates, whose completely expanded text25 is matched by the given pattern. See Text part of a line, and %?... special texts for text replacement. The pattern is a regular expression, as recognized by the Unix ed line-editor. See Regular Expressions, for further information.

For example, it is possible to induce Gcal to display all fixed dates from the resource file doctor.rc for the current month, which are defined for dentists or oculists:

          gcal -f doctor.rc --month -I "[dD]entist|[oO]culist"

Each time a ‘_’ (underscore) character is found in the pattern argument, this character is replaced by a real ‘ ’ (space) character.

You may depreciate the special meaning of the ‘_’ (underscore) character —in case this character itself is needed— by placing a ‘\’ (backslash) character before it, e.g. ‘\_’. If you need the ‘\_’ characters themselves, you have to protect the ‘\’ (backslash) character by another ‘\’ (backslash) character, e.g. ‘\\_’.

--ignore-case
Ignores all case distinctions in both the completely expanded text and the pattern of the --filter-text=pattern option. See Fixed date option --filter-text=pattern.
--revert-match
Displays all those fixed dates, whose completely expanded text does not match the pattern of the --filter-text=pattern option. See Fixed date option --filter-text=pattern.
-c|C[-]
--today
--list-of-fixed-dates[=short|long]
--descending-fixed-dates[=short|long]
Activate the fixed date function and display fixed date messages, if any.
-c
--today
--list-of-fixed-dates=short
Activate fixed date function (use standard resource file implicitly) and list all dates related to the actual system date (==today), sorted in ascending order. If no fixed dates related to the current day are found, no fixed date messages are displayed and the program is terminated with an error code. See Error Code 1.
-c-
--descending-fixed-dates=short
Activate fixed date function (use standard resource file implicitly) and list all dates related to the actual system date (==today), sorted in descending order. If no fixed dates related to the current day are found, no fixed date messages are displayed and the program is terminated with an error code. See Error Code 1.
-C
--list-of-fixed-dates=long
Activate fixed date function (use standard resource file implicitly) and list all dates related to the actual system date (==today), sorted in ascending order. If no fixed dates related to the current day are found, an “empty” fixed date message is displayed which is only consisting of the date.
-C-
--descending-fixed-dates=long
Activate fixed date function (use standard resource file implicitly) and list all dates related to the actual system date (==today), sorted in descending order. If no fixed dates related to the current day are found, an “empty” fixed date message is displayed which is only consisting of the date.

-f|F name[+...]
--resource-file=name[+...]
Activate fixed date function and use file name instead of the standard resource file. Then list all dates, sorted in ascending order which occur in the fixed date period. If no other fixed date period is specified, the actual system date (==today) is used for the fixed date period. If the option letter f of the short-style option is used and no dates related to the fixed date period are found in name, no fixed date messages are displayed and the program is terminated with an error code. See Error Code 1. If the option letter F of the short-style option is used and no dates related to the fixed date period are found in name, an “empty” fixed date message is displayed which is only consisting of the date.

You can use more than one resource file name by connecting them with a ‘+’ character, e.g.:

--resource-file=./foo+xyz+/data/bar+$HOME/.gcalrc resp.,
-f ./foo+xyz+/data/bar+$HOME/.gcalrc

respects all files given in the preceding argument by using a special file search mechanism. See File searching mechanism, for more details. Use /dev/null to avoid the use of the standard resource file, useful for creating empty fixed date lists. If a single ‘-’ character is given as file name, like --resource-file=./foo+-+xyz or -F-, but not -F -, Gcal reads and processes all input received from the standard input channel.

You may depreciate the special meaning of the ‘+’ separator character —in case this character itself is needed— by placing a ‘\’ (backslash) character before it, e.g. ‘\+’. If you need the ‘\+’ characters themselves, you have to protect the ‘\’ (backslash) character by another ‘\’ (backslash) character, e.g. ‘\\+’.

Each time a ‘_’ (underscore) character is found in name, this character is replaced by a real ‘ ’ (space) character.

You may depreciate the special meaning of the ‘_’ (underscore) character —in case this character itself is needed— by placing a ‘\’ (backslash) character before it, e.g. ‘\_’. If you need the ‘\_’ characters themselves, you have to protect the ‘\’ (backslash) character by another ‘\’ (backslash) character, e.g. ‘\\_’.

-# line
--here=line
Activate fixed date function and use the line argument together with the standard resource file respectively additional resource files. The line argument has to be a valid line as it may occur in a Gcal resource file (see Structure of resource file), and is always evaluated last after the processing of all resource files, so dealing with references to exported local date or text variables is enabled. This option may be given multiple and it will be processed exactly in the given order. All dates are listed, sorted in ascending order which occur in the fixed date period. If no other fixed date period is specified, the actual system date (==today) is used for the fixed date period. If no dates related to the fixed date period are found in the line, no fixed date messages are displayed and the program is terminated with an error code. See Error Code 1.

For example, the call:

          gcal -# "0*d1su#99su.7 ^%Z" --here="#include <foo>" -y

causes the implicit processing of the standard resource file just before the further resource file line ‘0*d1su#99su.7 ^%Z’ and following ‘#include <foo>’ are processed, and that as if these lines were a physical part of the standard resource file.

Each time a ‘_’ (underscore) character is found in line, this character is replaced by a real ‘ ’ (space) character.

You may depreciate the special meaning of the ‘_’ (underscore) character —in case this character itself is needed— by placing a ‘\’ (backslash) character before it, e.g. ‘\_’. If you need the ‘\_’ characters themselves, you have to protect the ‘\’ (backslash) character by another ‘\’ (backslash) character, e.g. ‘\\_’.

Please note:
If the short-style option -c and/or its modifiers t|[w|m|y[+|-], or the short-style option -f is/are given in upper-case, e.g.:

     -C
     -F foo.bar
     -CeT
     -c-aW+
     -CeaxY-
     -c-M

Gcal displays fixed date messages for every day of the requested period.

The modifiers of a combined/complex/packed short-style fixed date option must be constructed according to following steps, because Gcal treats them as positional parameters:

First step: Representation-of-text-modifier
a, A, e|E, J, k, o, Q, U, x, z, Z
Second step: Period-of-fixed-dates-modifier
d, l, t|T, w|W|m|M|y|Y[+|-], n+|-, nd, nw, *dn[www], *wn[www], @e|t|dvar[[+|-]n], @e|t|dvar[+|-]nwww, mmdd, mmwwwn

If you want to operate with the preceding modifiers, an explicit -c|C[-] short-style option must be leading on the one hand, e.g.:

     -c-t
     -cw-
     -CZdekloQUzJaxA12+

and only one period defining fixed date period modifier may be given26.

Or on the other hand, the modifiers must be given as single character options or composed into a single command line word, and additionally either the short-style option -c|C[-], -f|F name[+...] or -# line27 must be given like:

     -c -t
     -w- -c
     -a -Ad -e -kloQUxz -C12+
     -F foo.bar -dJZA -l*d10
     --here="; Comment" -dZAa

If the modifiers are given as single character options or composed into a single command line word, and one of the t|T|[w|W|m|M|y|Y[+|-]] modifiers is used28, it is unnecessary to give a -c|C[-] respectively -f|F name[+...] short-style option29 to activate the fixed date function of Gcal, because it is triggered implicitly by means of these modifiers / alias names.

See Coding Scheme, whose tables explain the relations between the date part (yyyy...) of a resource file line and the modifiers, the short-style option -c|C[] —which is used for enabling the fixed date feature— respectively the long-style option --period-of-fixed-dates=argument may have, i.e. they point out all possible correspondences. This is necessary because Gcal does not respect all entries found in a resource file if a fixed date argument is given, it respects only those entries which have a definite relation to the fixed date argument to avoid the output of redundant information!

Fixed date text modifiers and options:

--biorhythm-axis=number
The width of the biorhythm text graphics —which can be created by means of the biorhythm text graphics %;[date] special text— is changed to number characters for each axis of the bar. The number argument must be an integer value between 1...100, the default number of characters is 20. If the number divides 100 with a remainder, it is internally reduced to the nearest number that divides 100 without any remainder. This means, only the numbers 1, 2, 4, 5, 10, 20, 25, 50 and 100 are factually respected, so a number argument of 19 is internally reduced to 10.

For example:

          

$ cat bio.rc -| 0*d1#999 %;19620921 $ gcal -fbio.rc %19961212 -s0 -xw --biorhythm-axis=19 -| -| Thu, Dec <12th>1996: 0- I P1 E +0 -| Fri, Dec 13th 1996: 0- I P 1 +0 -| Sat, Dec 14th 1996: 0- @ E 0 +0 -| Sun, Dec 15th 1996: 0- P IE 0 +0 -| Mon, Dec 16th 1996: 0- P E I 0 +0 -| Tue, Dec 17th 1996: 1-P E I0 +0 -| Wed, Dec 18th 1996: 0- @ 1 +0

See Biorhythm %?[date] special texts, for more details.

--moonimage-lines=number
The height of the Moon phase text graphics —which can be created by means of the Moon phase text graphics %Z[date] special text— is changed to number lines. The number argument must be an integer value between 6...30, the default number of lines is 12.

For example:

          

$ gcal -f/dev/null -#0*d1#999_%Z__%O %19950407 -x --moon=8 -| -| Fri, Apr < 7th>1995: ( @@@@@ -| ( @@@@@@@@ -| ( @@@@@@@@@@@ -| ( @@@@@@@@@@@@ -| ( @@@@@@@@@@@@ -| ( @@@@@@@@@@@ -| ( @@@@@@@@@@ -| ( @@@@@@@ 42%+

See Moon phase %[format]?[date] special texts, for more details.

a
--include-resource-file-name
Extend fixed date text by the name of the resource file and the line number which the fixed date text comes from, e.g.:
          Mon, Jan   1st 1995: (`Eternal holiday list'#00003) New Year's day
          Mon, Jan   1st 1995: (.gcalrc#00987) No fixed dates
          ...

A
--alternative-format
Instead of using the standard list format, e.g.:
          Mon, Jan   1st 1995: New Year's day
          Mon, Jan   1st 1995: No fixed dates
          ...

Gcal uses the alternative list format, e.g.:

          Mon, Jan   1st 1995:
          New Year's day
          No fixed dates
          ...

e
--include-holidays=long
Enable inclusion of all built-in eternal holiday dates. This includes legal holidays and memorial days.
E
--include-holidays=short
Enable inclusion of those built-in eternal holiday dates which are legal holidays only.
g[text]
--grouping-text[=text]
Group fixed dates by day by using the text separator. If text is not given, the built-in text30 is used for grouping, e.g.:
          

$ gcal -Cxw -cg -| -| Sun, Nov 6th 1994: Text 1 -| Sun, Nov 6th 1994: Text 2 -| -| Mon, Nov 7th 1994: Text 3 -| -| Tue, Nov 8th 1994: Text 4 ... $ gcal -Cxw -g'-A_user\_defined-~-grouping text-' -| -| Sun, Nov 6th 1994: Text 1 -| Sun, Nov 6th 1994: Text 2 -| -A user_defined- -| -grouping text- -| Mon, Nov 7th 1994: Text 3 -| -A user_defined- -| -grouping text- -| Tue, Nov 8th 1994: Text 4 ...

The text may contain references to global date and text variables (see Fixed date option --date-variable=argument, and Fixed date option --date-variable=argument). Furthermore, all special texts which cause a text replacement may be used in the text (see %?... special texts for text replacement).

Each time a ‘~’ (tilde) or ‘^’ (caret) character is found in text, this character is replaced by a real ‘\n’ (newline) character.

You may depreciate the special meaning of the ‘~’ (tilde) character —in case this character itself is needed— by placing a ‘\’ (backslash) character before it, e.g. ‘\~’. If you need the ‘\~’ characters themselves, you have to protect the ‘\’ (backslash) character by another ‘\’ (backslash) character, e.g. ‘\\_’. All above mentioned facts are also valid for the ‘^’ (caret) character.

Each time a ‘_’ (underscore) character is found in text, this character is replaced by a real ‘ ’ (space) character.

You may depreciate the special meaning of the ‘_’ (underscore) character —in case this character itself is needed— by placing a ‘\’ (backslash) character before it, e.g. ‘\_’. If you need the ‘\_’ characters themselves, you have to protect the ‘\’ (backslash) character by another ‘\’ (backslash) character, e.g. ‘\\_’.

k
--include-week-number
The leading date of a fixed date message is either extended by the ISO week number or the standard week number. See Calendar option --starting-day=argument, Calendar option --iso-week-number=yes|no, and Aspects in Internationalization, for further details.
o
--omit-multiple-date-part
Omit displaying the leading date of a fixed date message in case more than one message refers to that date31, e.g.:
          

$ gcal -cxo -| -| Sun, Nov 6th 1994: Text 1 -| Text 2 ...


Q
--suppress-fixed-dates-list-separator
Suppress displaying of the blank line which is always leading a fixed date list. For example, to cause Gcal to print only the number of days between 1st January 1970 and 1st January 1980, you can call the program like this:
          

$ gcal -f /dev/null -QUx %19800101 -#0_%j-2440588 -| 3652


U
--suppress-date-part
Suppress displaying the leading date of a fixed date message, e.g.:
          

$ gcal -cxU -| -| Text 1 -| Text 2 ...


J
--suppress-text-part
Suppress displaying the text part of a fixed date message, e.g.:
          

$ gcal -cxJ -| -| Sun, Nov 6th 1994: -| Sun, Nov 6th 1994: ...


x
--exclude-fixed-dates-list-title
Suppress the title text line of the fixed date list.
--heading-text=text
Changes the title text line of the fixed date list. Instead of displaying the default ‘Fixed date list:’ text, any other text can be used as heading text of the fixed date list, e.g.:
          

$ gcal -cUJ --heading-text=Hello,_it_is_%K_,~%t__o'clock -| -| Hello, it is Sunday, -| 14:32 o'clock -| -| Sun, Nov 6th 1994: ...

The text may contain references to global date and text variables (see Fixed date option --date-variable=argument, and Fixed date option --date-variable=argument). Furthermore, all special texts which cause a text replacement may be used in the text (see %?... special texts for text replacement).

Each time a ‘~’ (tilde) or ‘^’ (caret) character is found in text, this character is replaced by a real ‘\n’ (newline) character.

You may depreciate the special meaning of the ‘~’ (tilde) character —in case this character itself is needed— by placing a ‘\’ (backslash) character before it, e.g. ‘\~’. If you need the ‘\~’ characters themselves, you have to protect the ‘\’ (backslash) character by another ‘\’ (backslash) character, e.g. ‘\\_’. All above mentioned facts are also valid for the ‘^’ (caret) character.

Each time a ‘_’ (underscore) character is found in text, this character is replaced by a real ‘ ’ (space) character.

You may depreciate the special meaning of the ‘_’ (underscore) character —in case this character itself is needed— by placing a ‘\’ (backslash) character before it, e.g. ‘\_’. If you need the ‘\_’ characters themselves, you have to protect the ‘\’ (backslash) character by another ‘\’ (backslash) character, e.g. ‘\\_’.

z
--include-consecutive-number
Display consecutive numbers of fixed date messages.
Z
--zero-dates-only
Display only those dates, for which fixed dates do not exist, i.e. all “empty” fixed dates only consisting of the date.

Fixed date period modifiers and options:

--leap-day=february|march
The leap day32 is observed in non-leap years.
--leap-day=february
A fixed date that appears in every year and which is related to the leap day, is displayed on the 28th February in non-leap years.
--leap-day=march
A fixed date that appears in every year and which is related to the leap day, is displayed on the 1st March in non-leap years.

d
--include-today
If lists of periods are generated, include the actual date into the list. See Fixed date option --list-mode, how to create a list of periods.
l
--list-mode
Generate a list of periods instead of a single period.
Please note:
The following examples assumes the actual system date is the 17th February of any year (00000217), weeks start on Mondays and ISO week numbers are used!
--period-of-fixed-dates=argument

nd
*dn
Single date of absolute day n == ‘1...365|366|999 of the actual year; the intensity level is the same as the simple -c option. If the value 999 for n is given, the last day of the year (31st December) is assumed.
lnd
l*dn
List dates starting yesterday or tomorrow (depending on the given day number n) and ending on the n'th absolute day of the actual year; the intensity level is the same as the -cy option.
n+|-
Single date of day actual day ‘+/- n days of the actual year; the intensity level is the same as the simple -c option.
ln+|-
List dates starting yesterday ‘-’ or tomorrow ‘+’ and ending on actual day ‘+/- n days of the actual year; the intensity level is the same as the -cy option.
nw
Single dates of week number n == ‘0|1...52|53|99 of the actual year; the intensity level is the same as the -cw option. See Calendar option --starting-day=argument, Calendar option --iso-week-number=yes|no, and Aspects in Internationalization, for more details.
lnw
List dates starting yesterday or tomorrow (depending on the given week number n) and ending on the first respectively last day of given week number n == ‘0|1...52|53|99 of the actual year; the intensity level is the same as the -cy option. See Calendar option --starting-day=argument, Calendar option --iso-week-number=yes|no, and Aspects in Internationalization, for further details.
mmdd
Single date of day dd in month mm of the actual year; the intensity level is the same as the simple -c option.
lmmdd
List dates starting yesterday or tomorrow (depending on the value given in mmdd) and ending on day dd of month mm of the actual year; the intensity level is the same as the -cy option.
mmwwwn
Single date of n'th == ‘1...5|9 weekday dd|www in month mm of the actual year; the intensity level is the same as the simple -c option.
lmmwwwn
List dates starting yesterday or tomorrow (depending on the value given in mmwwwn) and ending on n'th == ‘1...5|9 weekday dd of month mm of the actual year; the intensity level is the same as the -cy option.
*dnwww
Single date of n'th == ‘1...51|52|53|99 weekday www of the actual year; the intensity level is the same as the simple -c option.
l*dnwww
List dates starting yesterday or tomorrow (depending on the value given in n) and ending on n'th == ‘1...51|52|53|99 weekday www of the actual year; the intensity level is the same as the -cy option.
*wn[www]
Single date of weekday www of n'th == ‘0|1...52|53|99 week of the actual year; the intensity level is the same as the simple -c option. If no weekday www is given, the starting day of the week is assumed for the weekday www. See Calendar option --starting-day=argument, Calendar option --iso-week-number=yes|no, and Aspects in Internationalization, for more details.
l*wn[www]
List dates starting yesterday or tomorrow (depending on the value given in n) and ending on weekday www of n'th == ‘0|1...52|53|99 week of the actual year; the intensity level is the same as the -cy option. If no weekday www is given, the starting day of the week is assumed for the weekday www. See Calendar option --starting-day=argument, Calendar option --iso-week-number=yes|no, and Aspects in Internationalization, for further details.
@e[[+|-]n]
Single date of day n relative to the Easter Sunday's date of the actual year; the intensity level is the same as the simple -c option.
l@e[[+|-]n]
List dates starting yesterday or tomorrow (depending on the value given in n) and ending on n'th day relative to the Easter Sunday's date of the actual year; the intensity level is the same as the -cy option.
@e[+|-]nwww
Single date of n'th weekday www relative to the Easter Sunday's date of the actual year; the intensity level is the same as the simple -c option.
l@e[+|-]nwww
List dates starting yesterday or tomorrow (depending on the value given in n) and ending on n'th weekday www relative to the Easter Sunday's date of the actual year; the intensity level is the same as the -cy option.
@t[[+|-]n]
Single date of day n relative to today's date of the actual year; the intensity level is the same as the simple -c option.
l@t[[+|-]n]
List dates starting yesterday or tomorrow (depending on the value given in n) and ending on n'th day relative to today's date of the actual year; the intensity level is the same as the -cy option.
@t[+|-]nwww
Single date of n'th weekday www relative to today's date of the actual year; the intensity level is the same as the simple -c option.
l@t[+|-]nwww
List dates starting yesterday or tomorrow (depending on the value given in n) and ending on n'th weekday www relative to today's date of the actual year; the intensity level is the same as the -cy option.
@dvar[[+|-]n]
Single date of the day n relative to that date of the actual year, which is referenced by the date variable dvar; the intensity level is the same as the simple -c option.
l@dvar[[+|-]n]
List dates starting yesterday or tomorrow (depending on the value given in n) and ending on the n'th day relative to that date of the actual year, which is referenced by the date variable dvar; the intensity level is the same as the -cy option.
@dvar[+|-]nwww
Single date of the n'th weekday www relative to that date of the actual year, which is referenced by the date variable dvar; the intensity level is the same as the simple -c option.
l@dvar[+|-]nwww
List dates starting yesterday or tomorrow (depending on the value given in n) and ending on the n'th weekday www relative to that date of the actual year, which is referenced by the date variable dvar; the intensity level is the same as the -cy option.
t|T
--tomorrow long-style option
List dates related to tomorrow.
w|W[+|-]
--week long-style option
--end-of-week long-style option
--start-of-week long-style option
Display dates related to the week.
See Calendar option --starting-day=argument.
m|M[+|-]
--month long-style option
--end-of-month long-style option
--start-of-month long-style option
Display dates related to the month.
y|Y[+|-]
--year long-style option
--end-of-year long-style option
--start-of-year long-style option
Display dates related to the year.


Next: , Previous: Options, Up: Command line arguments

3.1.2 Response file

If a @file command line argument is given, a response file by the name of file will be used, i.e. options and commands are preloaded from that file. A response file may contain options and commands —which are preloaded by Gcal—, but no references to further response files. If such references to further response files are found, they are ignored. See Global option --response-file=name, for hints how to generate a response file automatically.

The searching scheme for a response file is the same as that for resource files, except no standard response file is respected. See File searching mechanism, for more details. Multiple response files may be given in the command line when Gcal is started, and they are processed exactly in that order as given, i.e. strictly sequential.

Each option and command must be on a single line, i.e. separated by a real ‘\n’ (newline) character. A line beginning with a ‘;’ (semicolon) character in the response file is treated as a remark and will not be used by Gcal (see Comment line).

Options must be defined before commands. If a response file contains any commands, then all further arguments after the @file option of the command line are ignored.

For example:

  1. Contents of response file file:
              Line     Text
              1        -j
              2        -Cw
              EOF
              
              

    $ gcal -i -b 3 @file -s 3 1994 ==> gcal -i -b 3 -j -Cw -s 3 1994

  2. Contents of response file file:
              Line     Text
              1        -j
              2        -Cw
              3        may 1992
              EOF
              
              

    $ gcal -i -b 3 @file -s 3 1994 ==> gcal -i -b 3 -j -Cw may

  3. Contents of response file file:
              Line     Text
              1        -j
              2        -Cw
              3        may
              4        1992
              EOF
              
              

    $ gcal -i -b 3 @file -s 3 1994 ==> gcal -i -b 3 -j -Cw may 1992


Next: , Previous: Response file, Up: Command line arguments

3.1.3 Actual date modifier

It is allowed to use that date —instead of the actual system date— which is defined by the %date command line argument. This means, fixed dates can be checked for any year and are respected in the same way, as if they would be fixed dates of the actual year.

The date must be denoted in one of these formats:

Some examples to this:

Please note:
The following examples assumes the actual system date is Wednesday, the 17th February 1993 (19930217), weeks start on Mondays and ISO week numbers are used!
The yyyy[mm[dd|wwwn]] format:

The yyyy*d|wn[www] format:

The yyyy@e|t|dvar[[+|-]n[www]] format:

The month name[dd] format:

The weekday name[n] format:

The dd format:


Previous: Actual date modifier, Up: Command line arguments

3.1.4 Commands

The commands control the periods Gcal respects. They can be partitioned into four major classes, namely single commands, special 3-Month mode commands, lists of commands and ranges of commands. Single commands and special 3-Month mode commands only create one calendar sheet, ranges of commands or list of commands create more than one calendar sheet per program run. If a list of commands is given, Gcal works sequentially on each single command given in the list, one by one. A range of commands is expanded first by Gcal and after expansion is done, Gcal works sequentially on each single command produced during the internal expansion step.

For understanding the notation used in the text below, mm is either a number, a month name or one of the special 3-Month mode commands ., .., .+ and .-. No lists or ranges of months or years can be created in case a special 3-Month mode command is given.

The range of mm is valid from 1 to 12 or valid from January to December. Both notations may be mixed. Month names may be abbreviated up to their first three characters. yyyy is a number. The range of yyyy is valid from 1 to 9999. A range (mm-mm or yyyy+yyyy or ...) must consist of two elements. A list (mm,...,mm or yyyy;...;yyyy or ...) must contain two elements minimum and may have any number of elements.

Here is a list of all ranges of commands, lists of commands and other command separator characters:


Next: , Previous: Commands, Up: Commands
3.1.4.1 Single commands

NOTHING
Current month of current year, called single month mode in the further context.
month name
Selected month of current year, e.g.:
          gcal may
          gcal OCTOBER
          gcal ja

yyyy
Selected year, called single year mode in the further context, e.g.:
          gcal 1992

But there is an exception of this general rule. If the specified year number is less or equal twelve, Gcal assumes that a selected month of the current year is wanted. If you want to have a selected year less or equal twelve, call Gcal like this

          gcal 1:6

or like this

          gcal 6+6

to obtain the year AD 6.

mm yyyy
mm/yyyy
Single month of selected year, e.g.:
          gcal 9 1992
          gcal 9/1992
          gcal Nov 1777
          gcal Nov/1777

:
Single fiscal year, starting on the actual month of the actual year and ending on month actual month-1 of the actual year+1, called implicit fiscal year in the further context, e.g.:
          gcal :

mm:
Single fiscal year, starting on month mm of the actual year and ending on month mm-1 of the actual year+1, called explicit fiscal year in the further context, e.g.:
          gcal 6:
          gcal feb:
          gcal NOVEMBER:

:yyyy
Single fiscal year, starting on the actual month of year yyyy and ending on month actual month-1 of year yyyy+1, also called explicit fiscal year in the further context, e.g.:
          gcal :1999

mm:yyyy
Single fiscal year, starting on month mm of year yyyy and ending at month mm-1 of year yyyy+1, called explicit fiscal year too in the further context, e.g.:
          gcal 7:1999
          gcal oct:1992
          gcal February:1777


Next: , Previous: Single commands, Up: Commands
3.1.4.2 3-Month mode commands

.
Previous, actual and next month of the current year, e.g.:
          gcal .

. yyyy
Previous, actual and next month of selected year, e.g.:
          gcal . 1992

..
Actual quarter of the current year, e.g.:
          gcal ..

.. yyyy
Actual quarter of selected year, e.g.:
          gcal .. 1992

.+
Actual and next two months of the current year, e.g.:
          gcal .+

.+ yyyy
Actual and next two months of selected year, e.g.:
          gcal .+ 1992

.-
Actual and previous two months of the current year, e.g.:
          gcal .-

.- yyyy
Actual and previous two months of selected year, e.g.:
          gcal .- 1992


Next: , Previous: 3-Month mode commands, Up: Commands
3.1.4.3 Lists of commands

mm,...,mm
List of specified months of the current year, e.g.:
          gcal 1,5,12
          gcal 3,1,5,3
          gcal june,9,jan

mm/yyyy,...,mm/yyyy
List of months in specified year, e.g.:
          gcal 1/1992,5,12/2001
          gcal june/1991,9/1801,jan

mm,...,mm yyyy
List of specified months of selected year, e.g.:
          gcal 3,7 1999
          gcal 1,dec,july 1777

yyyy;...;yyyy
List of specified years, e.g.:
          gcal 1992;1777;1899

mm:yyyy;...;mm:yyyy
List of specified fiscal years, e.g.:
          gcal 7:1999;8:1992;April:3

Other valid lists:

mm,mm/yyyy,...
Mixed list of months consisting of: mm mm/yyyy
          gcal 6,8,3/1999,feb/3,january

mm:;mm:yyyy;...
Mixed list of fiscal years of the given / actual year consisting of: mm: :yyyy mm:yyyy yyyy
          gcal 3:;1994;february:1999;:1777;JAN:

mm:;mm:;...
List of fiscal years of the actual year consisting of: mm:
          gcal 3:;august:;DEC:


Previous: Lists of commands, Up: Commands
3.1.4.4 Ranges of commands

mm-mm
Range of current months, e.g.:
          gcal 3-7
          gcal 11-8
          gcal MAY-dec
          gcal 12-aug

mm/yyyy-mm/yyyy
Range of months of year, e.g.:
          gcal 3/1991-july/1992
          gcal dec/1994-3
          gcal sep-dec/2000

mm-mm yyyy
Range of specified months of selected year, e.g.:
          gcal 3-7 1999
          gcal nov-3 1777
          gcal aug-dec 1992

mm-mm yyyy+yyyy
Range of specified months of selected years, e.g.:
          gcal 3-7 1999+2001
          gcal nov-3 1777+1600
          gcal aug-dec 1992+1994

mm yyyy-yyyy
mm/yyyy-yyyy
Range of specified month of selected years, e.g.:
          gcal AUGUST 1494-1497
          gcal 3/1993-1999
          gcal nov/3-1777

yyyy+yyyy
Range of specified years, e.g.:
          gcal 1992+1994

mm:yyyy+mm:yyyy
Range of specified fiscal years, e.g.:
          gcal 7:1999+8:1992
          gcal aug:1992+july:1999


Previous: Command line arguments, Up: Invoking Gcal

3.2 The GCAL environment variable

The environment variable GCAL can hold a set of default options for Gcal (see Environment Variable GCAL). These options are interpreted first at program start-up, and some can be overwritten by explicit command line arguments or values found in a @file response file. See Command line arguments, and Response file, for further information.

For example:

On Vax/VMS, the name of the environment variable is GCAL_OPT, to avoid a conflict with the symbol GCAL set for invocation of the program.

For example:


Next: , Previous: Invoking Gcal, Up: Top

4 Eternal Holidays

The eternal holiday list is created only for dates after AD 29. It is assumed that the Gregorian Reformation has occurred from 10th till 22nd March 1924 for all Christian-Orthodox holidays, which are inserted into the eternal holiday list.

The eternal holiday list can be displayed in different ways:

If you start Gcal without an explicit (fiscal) date and the eternal holiday list argument (see Calendar option --holiday-list[=long|short]), e.g.:

     gcal -qfr --holiday-list
     gcal -qfr -n
     gcal -qfr -n :

Gcal displays all holidays of the eternal holiday list that refer to the actual / fiscal year, without a leading calendar sheet.

In case you start Gcal with the eternal holiday list argument and a month (plus an additional year), e.g.:

     gcal -qbe --holiday-list july
     gcal -qbe -n july
     gcal -qbe -n 7 1993
     gcal -qbe -n 7/1993

Gcal displays a month calendar sheet of the specified month (of year), and trailing those holidays of the eternal holiday list that refer to the given month (of the given year).

If you start Gcal with the eternal holiday list argument and a simple year (or an explicit fiscal year), e.g.:

     gcal -qbe --holiday-list 1993
     gcal -qbe -n 1993
     gcal -qbe -n july:
     gcal -qbe -n :1993
     gcal -qbe -n 7:1993

Gcal displays a year calendar sheet of the specified year or fiscal year, and trailing all holidays of the eternal holiday list that refer to the given year or fiscal year.

In case you start Gcal with the eternal holiday list argument and a special 3-Month mode command (see 3-Month mode commands), e.g.:

     gcal -qbe --holiday-list .
     gcal -qbe -n .
     gcal -qbe -n ..
     gcal -qbe -n .+
     gcal -qbe -n .-

Gcal displays the according three months by using a fixed-style year calendar sheet, and trailing all holidays of the eternal holiday list that refer to these months.

In case you start Gcal with the eternal holiday list argument and a list or range of commands, it produces the according series of eternal holiday lists. See Lists of commands, and Ranges of commands, for further details.

Some annotations:

The following table lists all those characters which are used for marking an entry in the eternal holiday list, i.e. directly lead its date:

Character Description

+ Legal holiday which is valid in the whole country. Is automatically provided with highlighting sequences respectively marking characters.
# Legal holiday which is valid in major parts of the whole country. Is automatically provided with highlighting sequences respectively marking characters.
* Legal holiday which is valid in minor parts of the whole country. Is not provided with highlighting sequences respectively marking characters.
- Other holiday which serves for memorial or remarking purposes only. Is not provided with highlighting sequences respectively marking characters.

By using the --cc-holidays=cc[+...] option, it is possible to provide the eternal holiday list with additional country specific holidays. Thereafter, those country specific holidays are part of the list. See Calendar option --cc-holidays=cc[+...]. For example:

     --cc-holidays=be+fr

causes the inclusion of Belgian and French holidays into the eternal holiday list. The inclusion of country specific holidays is not coupled to Gcal's internationalization (see Aspects in Internationalization). This means, no country specific holidays are automatically respected at program start-up for a definite territory or country. So it is up to the user to decide which country specific holidays are included into the eternal holiday list. See The GCAL environment variable, for information how Gcal can be induced to include the country specific holidays automatically into the eternal holiday list at program start-up.

The free selection of the different country specific holidays can be used very ingenious in case information of a definite territory or country is required. Assuming a business man from Germany proposes to travel to Italy in November and needs the information which legal holidays are celebrated there on working days so he is able to plan his dates. This can be determined as follows:

     gcal -f /dev/null -q IT -D r -cE nov


Next: , Previous: Eternal Holidays, Up: Top

5 Fixed Dates

This chapter describes how to use the fixed date feature of Gcal. Normally, the fixed dates are stored line by line in a so-called resource file (see Resource file). On request, Gcal searches any of such resource files for those fixed dates, that are happening in the period for which a fixed date list is wanted. If Gcal has found any fixed dates that are happening in the requested period, the program displays them collectively as a fixed date list.

Thus, each time you execute Gcal in simple single month mode, i.e. no explicit month, year or fiscal year is given in the command line, but the fixed date argument, e.g.:

     gcal --list-of-fixed-dates
     gcal -c

it checks the resource file for dates and processes those that refer to the actual system date (==today). Then Gcal displays all fixed dates found in the resource file which refer to the actual day (week/month/year) of the actual year, without a leading calendar sheet.

Some more examples:

     gcal --ast -ce
     gcal -cw-
     gcal -c-m
     gcal -c-y-
     gcal -qbe -jcb -c-et
     gcal --zod -cey-
     gcal -qfr -jc -cey

The fixed date list can be embraced by different other leading and trailing output, respectively, that is also created by Gcal:

In case you start Gcal with the fixed date argument and/or a month and/or an explicit year or fiscal year; respectively with the special 3-Month mode command, e.g.:

     gcal -c july
     gcal -qfr -ce 7 1994
     gcal -c-y 7/1994
     gcal -c 7:1993
     gcal -c 1993
     gcal -c .
     gcal -c .+

Gcal displays a (three) month / year calendar sheet of the specified respectively actual month / year, and trailing those fixed dates found in the resource file that refer to the given period; the intensity level is the same as the -cy option if the period refers to a year or fiscal year or to a three month period, respectively, is the same as the -cm option if the period refers to a month.

If you start Gcal without an explicit date and the fixed date argument in connection with the eternal holiday list argument, e.g.:

     gcal -qbe -n -c
     gcal -qbe -n -Cm
     gcal -qbe -n -Cl1224
     gcal -qbe -n -cl3+
     gcal -qbe -n -4-

then Gcal displays all fixed dates found in the resource file that refer to the requested period, and after that all holidays of the eternal holiday list that refer to the whole actual year, without a leading calendar sheet. See Eternal Holidays, for more details how to use an eternal holiday list.

Annotation to previous examples:

Each time you execute Gcal in simple single year mode, i.e. no explicit month, year or fiscal year is given in the command line, but the fixed date argument (with optional modifiers) and the number of blocks argument (see Calendar option --blocks=number), e.g.:

     gcal -c --blocks=3
     gcal -C-em -b 3 --cc-holidays=be
     gcal -c-t -b 6 -jc

it checks the resource file for dates and processes those that refer to the actual system date (==today). Gcal displays a leading year calendar sheet, and all fixed dates found in the resource file that refer to the actual day (week/month/year) of the actual year.

You can list fixed dates of past, present or future month/years, too. This can be done on the one hand, if you use the %date option in the way you require (see Actual date modifier), and on the other hand, if a command respectively a list or range of commands is used.

For example:

gcal -qbe -c -n- 1993
Lists all fixed dates of entire 1993 in ascending order, and the eternal holiday list of entire 1993 in descending order; the intensity level is the same as the -cy option.
gcal -c- july:1993
Lists all fixed dates of fiscal year —starting in July 1993 and ending in June 1994— in descending order; the intensity level is the same as the -cy option.
gcal -qbe -ce july 1993
Lists all fixed dates of July 1993 inclusive all eternal holidays merged into this list in ascending order; the intensity level is the same as the -cm option.
gcal -qbe -c-e -n 1993+1996
Lists all fixed dates of entire 1993, 1994, 1995 and 1996 (series of years) inclusive all eternal holidays merged into this list in descending order, and the eternal holiday list related to all above years in ascending order; the intensity level is the same as the -cy option.
gcal -cm %19920317
Lists all fixed dates of March 1992 in ascending order.
gcal -qbe %1994@e -n -c
Lists all fixed dates of Easter Sunday 1994 in ascending order, and the eternal holiday list of entire 1994 in ascending order.


Next: , Previous: Fixed Dates, Up: Fixed Dates

5.1 Resource file

This section describes how to use a resource file that contains fixed dates and appointments. The name of the standard resource file is HOME/.gcalrc37.

Gcal uses a special file searching mechanism:

  1. The Gcal program scans the file directories which are referenced in the environment variable GCALPATH (see Environment Variable GCALPATH) to find the standard resource file. The GCALPATH environment variable contains a (‘:’) colon-separated38 list of file directories. If no such environment variable is defined and set, Gcal omits this step.
  2. If the above action fails, Gcal looks for the standard resource file in the file directory which is referenced in the environment variable HOME. If no HOME environment variable is defined and set, Gcal also omits this step. See Environment Variable HOME.
  3. If the above action fails, Gcal inspects the user data file directory39 to find the standard resource file. This file directory is a file directory relative to the HOME file directory. If an environment variable GCAL_USR_DATADIR is set, Gcal appends the contents of this environment variable to the contents of the HOME environment variable, and tries to use this file directory instead of using the burned-in default name of this file directory (see Environment Variable GCAL_USR_DATADIR). If no HOME environment variable is defined and set, Gcal of course also omits this step.
  4. If all above actions fail, Gcal inspects the system data file directory40 to find the standard resource file. This file directory is a file directory absolute to the root/$prefix file directory. If an environment variable GCAL_SYS_DATADIR is set, Gcal tries to use this file directory instead of using the burned-in default name of this file directory (see Environment Variable GCAL_SYS_DATADIR).

If the standard resource file is not found during the steps 1...4 of the file searching mechanism, no fixed date messages will be created!

In case the --debug=abort option is given and no standard resource file is found during the steps 1...4 of the file searching mechanism, the Gcal program will be aborted with an error code. See Error Code 118, and Global option --debug=abort, for more information.

If a -f|F name[+...] respectively --resource-file=name command line argument is given, a file name will be used for the resource file instead of the standard resource file. See Fixed date option --resource-file=name.

Annotation:

An extended file name contains one ore more ‘/’ (slash) characters41 and denotes a file, whose fixed access path either starts from the root file directory, like ‘/foo/bar/file’, or from the actual file directory, like ‘./bar/file’ or ‘../bar/file’. If name is an extended file name:

A simple file name denotes a file, whose access-path either does not start from the root file directory or from the actual file directory, like ‘file’ or ‘bar/file’. If name is a simple file name:


Next: , Previous: Resource file, Up: Resource file

5.1.1 Structure of resource file

First of all, a Gcal resource file is a plain ascii text file. This text file may be created by any text editor or by redirecting the standard output channel to a file, e.g.:

     

$ echo '19930217 Text'>> resource-file <RET>

A special —but simple— line structure is required so Gcal is able to interpret its contents. Each fixed date entry in a resource file must be split into two parts, namely a date part and an optional text part which must be separated by one whitespace42 character minimum. It is unnecessary to give a whitespace separator character if no text part is specified.

A line must always end with a ‘\n’ (newline) character, except it is the last line of a resource file. The maximum length of a line is limited to INT_MAX43 characters. A newline character is automatically appended to the line if the standard output channel is directed to a file. A newline character is appended to the typed line in a text editor window if it is completed by pressing the <RET> key. In case the used text editor does not generate the newline character in this way, it should be set to this mode of operation, otherwise this text editor is useless for creating Gcal resource files.

The line structure of fixed date entries is:

     date part [ whitespace text part ] newline

or more concrete, e.g.:

     yyyy[mm[dd|wwwn]] [ whitespace text ] newline

or much more concrete, e.g.:

     19940217 Hi, I'm the text!

Besides fixed date entries, a resource file may contain further entries like:

Comments...

     ; A remarked line
     ;     A formatted and multi-line \
           remark

Include directives...

     #include <file name>
     #include "file name"

Date variable assignments respectively operations...

     dvar=NOTHING
     dvar=mmdd
     dvar=mmwwwn
     dvar=*dn[www]
     dvar=*wn[www]
     dvar=dvar[[+|-]n[www]]
     dvar++
     dvar--
     dvar+=[+|-]n
     dvar-=[+|-]n
     dvar+=nwww
     dvar-=nwww

Text variable assignments respectively operations...

     tvar=[text]
     tvar?[command]
     tvar:[command]
     tvar++
     tvar--
     tvar+=[+|-]n
     tvar-=[+|-]n

Text variable references...

     tvar

Text variable references at the beginning of a Gcal resource file line may only be used if it is ensured that they are expanded to a valid Gcal resource file line.


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5.1.2 Date part of a line

The structure of a date part —which gives Gcal the information at which date a fixed date happens— of a line in the resource file is

eitheryyyy[mm[dd|wwwn]]

yyyy
(4 digits), is the year including the century (range 0000...9999). Leading zeroes are required in case the defined year is less than 1000 and other components of the date part are trailing the year.
mm
(2 digits or 3 characters), is the month (range 00...12 or 99, respectively Jan, Feb...). A given 99 for the month means the last month of the year (== December). Leading zeroes are required in case the defined month is less than 10 and other components of the date part are trailing the month.
dd
(2 digits), is the day (range 00...31 or 99). A given 99 for the day means the last day of the month. Leading zeroes are required in case the defined day is less than 10 and other components of the date part are trailing the day.
www
(2...3 characters), is a short weekday name (range Mon...Sun).
n
(1 digit), is the n'th weekday www of month (range 1...5 or 9).
  • n == 1...5
    n'th weekday www of month.
  • n == 9
    Last weekday www of month.

oryyyy*d|wn[www]

yyyy
(4 digits), is the year including the century (range 0000...9999). Leading zeroes are required in case the defined year is less than 1000 and other components of the date part are trailing the year.
*d
(2 characters), is the reference to an ordinary date.
*w
(2 characters), is either the reference to a date of an ISO week or the reference to a date of a standard week.
n
(1...3 digits), is the value in days or in weeks, the fixed date occurs. A given 99 connected with a short weekday name means the last weekday www of the year. A given 999 connected with *d means the last day of a year, i.e. the 31st December. If the computed date does not occur in the year, i.e. exceeds the year bounds, the fixed date message is suppressed.
www
(2...3 characters), is a short weekday name (range Mon...Sun).

oryyyy@e|t|dvar[[+|-]n]

yyyy
(4 digits), is the year including the century (range 0000...9999). Leading zeroes are required in case the defined year is less than 1000 and other components of the date part are trailing the year.
@e
(2 characters), is the reference to the Easter Sunday's date.
@t
(2 characters), is the reference to today's date.
@dvar
(2 characters), is the reference to a date variable.
[+|-]n
(1...4 alphanumeric characters), is the optional displacement value in days, the fixed date occurs relative to the Easter Sunday's date, relative to today's date, or relative to a date variables date. A given -999 means the first day of a year, i.e. the 1st January. A given +999 or 999 means the last day of a year, i.e. the 31st December. If the computed date does not occur in the year, i.e. exceeds the year bounds, the fixed date message is suppressed.

oryyyy@e|t|dvar[+|-]nwww

yyyy
(4 digits), is the year including the century (range 0000...9999). Leading zeroes are required in case the defined year is less than 1000 and other components of the date part are trailing the year.
@e
(2 characters), is the reference to the Easter Sunday's date.
@t
(2 characters), is the reference to today's date.
@dvar
(2 characters), is the reference to a date variable.
[+|-]nwww
(3...7 alphanumeric characters), is the optional displacement value in weekdays, the fixed date occurs relative to the Easter Sunday's date, relative to today's date, or relative to a date variables date. A given -99 means the first weekday www of the year. A given +99 or 99 means the last weekday www of the year. If the computed date does not occur in the year, i.e. exceeds the year bounds, the fixed date message is suppressed.

Please note:

Hint:
Preceding table ease misleading assumption that a fixed date, which shall be valid for any days of the year, can be defined with a date part only consisting of a 0. But that is only correct in that the so-defined fixed date is respected in some few fixed date periods only (see Coding Scheme).

If a fixed date is defined which shall be respected for any days of the year, it must be designed with a 0*d1#999 date part. For example, the same is likewise valid for fixed dates which represent a weekly event, and that shall be valid during all the year. Instead of creating such a fixed date with a 000000www date part (that is likewise respected in some few fixed date periods only), it should be defined with a date part like 0*d1www#99www.7. See Ranges of days, and Appearance factor of days, for further information.


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5.1.3 Further date part attributes

The date part —which is leading a fixed date text of a Gcal resource file line— may be provided with further attributes, that are either specifications of lists of days or ranges of days, which provide the information at which date a fixed date happens. More further attributes are the repetition factor as well as the appearance factor.

All of those date parts in a Gcal resource file line, which are structured as follows, may generally be provided with further attributes:

Attention:
If the date part is supplied with further attributes and the year of the fixed date is not given in a concrete manner, i.e. the year yyyy is set to zero, such kinds of fixed dates are only computed correctly in simple year bounds —which means during a current year— and not in fixed dates shown after the current year has changed, e.g. in fiscal years.


Next: , Previous: Further date part attributes, Up: Further date part attributes
5.1.3.1 Lists of days

A list of days is used to define recurrent fixed dates and to use only one line in the resource file for them, instead of using several lines in a resource file needed for defining these recurrent fixed dates separately.

A list of days is specified by a ‘,’ separator character; it must contain two elements minimum and may have any number of elements. A single element of the list may not be set to a zero value and be not concrete therefore. (This would not make any sense in this context.)

Assuming a fixed date shall always occur on the 1st and the 15th day in every month of the year 1996, e.g. ‘Tax returns’, one solution would be on the one hand a fixed date entry in the resource file for the 1st of the month and another entry for the 15th of the month, which would be a total of two entries in the resource file for such a fixed date.

On the other hand, this expense can be reduced to a total of only one entry in the resource file by using a list of days, which is likewise valid for the 1st and the 15th day in every month, that is

     19960001,15 Tax returns

The use of lists of days in the date part is permitted as follows:

Some examples to this:

000001fr3,12,99,mon,apr14,993,julfri3,08fr
In every year in January: on the 3rd Friday, on the 12th, on the last day of the month and on every Monday. And in every year: on the 14th April, on the 3rd December, on the 3rd Friday in July and on every Friday in August.
199600mon,fr,12
In the year 1996 in every month: on every Monday, on every Friday and on the 12th.
0*d1,1fr,999,17mo
In every year: on the first day of the year, on the 1st Friday of the year, on the last day of the year and on the 17th Monday of the year.
1996*w1fr,1,17mo,99fr
In the year 1996: on Friday of the 1st week, on Monday of the first week, on Monday of the 17th week and on Friday of the last week.
0@a,+1,-3,5,+4fr,2fr,-10sa
In every year: on the date of the date variable a, one day after the date of a, three days before the date of a, five days after the date of a, four Fridays after the date of a, two Fridays after the date of a and ten Saturdays before the date of a.
1996@e+1,-3,5,+4fr,2fr,-10sa
In the year 1996: one day after the Easter Sunday's date, three days before the Easter Sunday's date, five days after the Easter Sunday's date, four Fridays after the Easter Sunday's date, two Fridays after the Easter Sunday's date and ten Saturdays before the Easter Sunday's date.
1996@t+1,-3,5,+4fr,2fr,-10sa
In the year 1996: one day after today's date, three days before today's date, five days after today's date, four Fridays after the today's date, two Fridays after today's date and ten Saturdays before today's date.


Next: , Previous: Lists of days, Up: Further date part attributes
5.1.3.2 Ranges of days

A range of days just as a list of days is used to define recurrent fixed dates and to use only one line in the resource file for them, instead of using several lines in a resource file needed for defining these recurrent fixed dates separately.

A range of days is specified by a ‘#’ separator character and must consist of two elements, namely the starting day and the final day. The starting day and likewise the final day of the range may not be set to a zero value and be not concrete therefore. (This would not make any sense in this context.)

Assuming a fixed date shall always occur during the 1st and the 15th day (inclusive) in every month of the year 1996, e.g. ‘Inside work’, one solution would be on the one hand a fixed date entry in the resource file for the 1st of the month, another one for the 2nd of the month until the 15th of the month, which would be a total of 15 entries in the resource file for such a fixed date44.

On the other hand, this expense can be reduced to a total of only one entry in the resource file by using a range of days, which is likewise valid for the 1st until the 15th day in every month, that is

     19960001#15 Inside work

The use of ranges of days in the date part is permitted as follows:

Preceding table shows that the starting and ending day can only be specified by using date formats of the same type left and right the ‘#’ separator character. Thus, it is not explicitly possible to define a range of days by using different types of date formats, means, fixed date entries like:

     1996@e+3fr#1012 In the year 1996: every day that appears within the\
                     period of the date 3 Fridays after Easter Sunday's\
                     date until the 12th October.

cannot be defined like this. But this problem can be solved by using an inclusive date period %i[date][#[date]] special text for defining the ending day of the range45, and the fixed dates are simply produced until the last day of the year, e.g.:

     1996@e+3fr#+999 In the year 1996: every day that appears within the\
                     period of the date 3 Fridays after Easter Sunday's\
                     date until the 12th October.%i0#19961012

See Inclusive date period %i[date][#[date]] special text, for more details.

Some examples to this:

199600mon#fr
In the year 1996 in every month: every day that appears within the day sequence ‘mon, tue, wed, thu, fri’.
000000fr#mon
In every year in every month: every day that appears within the day sequence ‘fri, sat, sun, mon’.
000001fr3#12
In every year in January: every day that appears within the period of the 3rd Friday of the month until the 12th of the month.
00000112#fr3
In every year in January: every day that appears within the period of the 12th of the month until the 3rd Friday of the month.
00000112#augfri3
In every year: every day that appears within the period of the 12th January until the 3rd Friday of August.
0000sep13#99fr9
In every year: every day that appears within the period of the 13th September until the last Friday of December.
0*d1#1fr
In every year: every day that appears within the period of the 1st day of the year until the 1rd Friday of the year.
0*d99fr#333
In every year: every day that appears within the period of the last Friday of the year until the 333rd day of the year.
1996*w1fr#17mo
In the year 1996: every day that appears within the period of the Friday of the 1st week until the Monday of the 17th week.
0@a#+4fr
In every year: every day that appears within the period of the date of the date variable a until the 4th Friday after the date of the date variable a.
1996@e-3#+9fr
In the year 1996: every day that appears within the period of the date three days before the Easter Sunday's date until the 9th Friday after the date of the Easter Sunday's date.
1996@t-3#+99fr
In the year 1996: every day that appears within the period of the date three days before today's date until the last Friday of the year.


Next: , Previous: Ranges of days, Up: Further date part attributes
5.1.3.3 Repetition factor of days

A repetition factor of days is used to define recurrent fixed dates and to use only one line in the resource file for them, instead of using several lines in a resource file needed for defining these recurrent fixed dates separately.

A repetition factor of days (‘:n’) is specified by a ‘:’ character and must trail the day field —which must have a concrete value in a date part of a Gcal resource file and has not been set to a zero value— respectively either lead or trail an appearance factor of days. Except ranges of days or fixed dates which occur only on a definite weekday like ‘199600mon Every Monday 1996’, such a repetition factor may be specified in all possible codings of date parts of a Gcal resource file.

This factor may have values in range 1...999. Values greater than the real difference between the date of the first occurrence of the fixed date and the last day of the year are always reduced to this real difference. In this sense, any value greater 36546 means a repetition factor until the last day of the year.

Assuming a fixed date shall always occur on the 15th day in every month of the year 1996 and covers a period of four days (inclusive the 15th itself), e.g. ‘Co-workers training’, one solution would be on the one hand a fixed date entry in the resource file for the 15th of the month and the succeeding three days, which would be a total of four entries in the resource file for such a fixed date47.

On the other hand, this expense can be reduced to a total of only one entry in the resource file by using a repetition factor of days, which is likewise valid for the 15th and the three days which succeed the 15th in every month, namely

     19960015:4 Co-workers training

The use of repetition factors of days in the date part is permitted as follows:

Some examples to this:

000001fr3:11
In every year in January: every day that appears within the period of the 3rd Friday of the month and the succeeding ten days.
00000112:3
In every year in January: every day that appears within the period of the 12th of the month and the succeeding two days.
00000112:3,fr3:5
In every year in January: every day that appears within the period of the 12th of the month and the succeeding two days, and that appears within the period of the 3rd Friday of the month and the succeeding four days.
0*d1:1
In every year: every day that appears within the period of the 1st day of the year and no succeeding day.
0*d1:2
In every year: every day that appears within the period of the 1st day of the year and the succeeding day.
0*d99fr:333
In every year: every day that appears within the period of the last Friday of the year and the succeeding 332 days. Well, in cases a fixed date exceeds the year bounds, it will only be produced until the last day of the year.
1996*w1fr:17
In the year 1996: every day that appears within the period of the Friday of the 1st week and the succeeding 16 days.
0@a:4
In every year: every day that appears within the period of the date of the date variable a and the succeeding three days.
1996@e-3:9
In the year 1996: every day that appears within the period of the date three days before the Easter Sunday's date and the succeeding eight days.
1996@t-3:9
In the year 1996: every day that appears within the period of the date three days before today's date and the succeeding eight days.


Previous: Repetition factor of days, Up: Further date part attributes
5.1.3.4 Appearance factor of days

An appearance factor of days is used to define a concrete displacement of recurrent fixed dates.

An appearance factor of days (‘.n’) is specified by a ‘.’ character and must trail the day field —which must have a concrete value in a date part of a Gcal resource file and has not been set to a zero value— respectively either lead or trail a repetition factor of days. Except fixed dates which occur only on a definite weekday and are not specified by using a range of days, like ‘199600mon Every Monday 1996’, such an appearance factor may be specified in all possible codings of date parts of a Gcal resource file. This factor may be specified with each single element of lists of days, but in a range of days, this factor may trail only the final day of the range. Well, the use of such an appearance factor is only helpful if it is either given in a range of days, or if it is given together with a repetition factor.

This factor may have values in range 1...999. Fixed dates will be ignored if the factor takes values greater than the real difference between the date of the occurrence of the fixed date and the last day of the year, respectively the end of the period, for which the fixed dates shall either be produced or respected.

Assuming a fixed date shall always occur on the 15th day in every month of the year 1996 and covers a period of seven days (inclusive the 15th itself), but shall only be respected every third day (i.e. two days have to be skipped at a time) within this period, e.g. ‘Training-college’, one solution would be on the one hand a fixed date entry in the resource file for the 15th of the month, for the 18th and for the 21st of the month, which would be a total of three entries in the resource file for such a fixed date48.

On the other hand, this expense can be reduced to a total of only one entry in the resource file by using an appearance factor of days, which is likewise valid for the 15th, the 18th and the 21st in every month, namely on the one hand by the use of a repetition factor

     19960015:7.3 Training-college

or on the other hand by the use of a range of days

     19960015#21.3 Training-college

The use of appearance factors of days in the date part is permitted as follows:

Some examples to this:

000001fr3:11.3
In every year in January: every day that appears within the period of the 3rd Friday of the month and the succeeding ten days, but only every 3rd day within this period (skip two days at a time).
00000112:3.2
In every year in January: every day that appears within the period of the 12th of the month and the succeeding two days, but only every 2nd day within this period (skip one day at a time).
00000112:3.2,fr3:5.3
In every year in January: every day that appears within the period of the 12th of the month and the succeeding two days, but only every 2nd day within this period (skip one day at a time), and that appears within the period of the 3rd Friday of the month and the succeeding four days, but only every 3rd day within this period (skip two days at a time).
0*d1:10.1
In every year: every day that appears within the period of the 1st day of the year and the succeeding nine days, and this for any day within this period (skip zero days at a time).
0*d1:2.5
In every year: every day that appears within the period of the 1st day of the year and the succeeding day, but only every 5th day within this period (skip four days at a time). Well, the succeeding days (only one in this example) of the starting day (1st day of year) are not respected, because the next day resulted by the appearance factor exceeds the final day (resulted by the repetition factor) of the period.
0*d99fr:333.61
In every year: every day that appears within the period of the last Friday of the year and the succeeding 332 days, but only every 61st day within this period (skip 60 days at a time). Well, in cases a fixed date exceeds the year bounds, it will only be produced until the last day of the year. No succeeding day (332 in this example) of the starting day (last Friday of the year) is respected by reason of the displacement value of 60 days, because the next day resulted by the appearance factor exceeds the final day (resulted by the repetition factor) of the period (the last day of the year).
1996*w1fr:17.8
In the year 1996: every day that appears within the period of the Friday of the 1st week and the succeeding 16 days, but only every 8th day within this period (skip seven days at a time).
0@a:4.3
In every year: every day that appears within the period of the date of the date variable a and the succeeding three days, but only every 3rd day within this period (skip two days at a time).
1996@e-3:9.4
In the year 1996: every day that appears within the period of the date three days before the Easter Sunday's date and the succeeding eight days, but only every 4th day within this period (skip three days at a time).
1996@e3#-20sun.15
In the year 1996: every day that appears within the period of the date three days after the Easter Sunday's date until the 20th Sunday before the Easter Sunday's date, but only every 15th day within this period (skip 14 days at a time).
1996@t3#-20sun.15
In the year 1996: every day that appears within the period of the date three days after today's date until the 20th Sunday before today's date, but only every 15th day within this period (skip 14 days at a time).


Next: , Previous: Further date part attributes, Up: Resource file

5.1.4 Text part of a line

The text part of a line in a resource file can be any text you like. Indeed, some characters have a special meaning (‘%’, ‘$’, ‘~’, ‘^’ and ‘\’) and must be protected should the occasion arise that special character combinations are formed with them49 which might be used only textually. If the text part contains characters that are used for highlighting the text or format it for a printer, or characters with decimal values above 127 in the code table of the used character set50 not produced by Gcal itself, such characters respectively sequences are displayed by Gcal in an uninterpreted manner! For that very reason, it can happen that the output of such characters can potentially create problems with the used screen device driver software and/or the external pager program, likewise mailing of such texts by means of electronic mail.

So-called NUL characters51 may also occur in the text part, but they only cause the suppression of all succeeding characters in the line. In my opinion, it makes no perceptible sense to output these NUL characters uninterpreted, so they are used for remarking purposes only; besides, the NUL characters would lead to the same problems as already mentioned above.

A line of the resource file is continued on the next line if a ‘\-\n (backslash-newline) character sequence is found, e.g.:

The line:

     000000Mo Every Monday

and the lines:

     000000Mo \
     Every \
     Monday

produce the same output and are essentially equivalent.

Furthermore, you can break-up the text of a long text part at any place you like. The term long means in this context, that the text displayed by Gcal would override the right text margin of the screen respectively break-up at that margin.

Each time a ‘~’ (tilde) character is found in the text part, this character is replaced by a real ‘\n’ (newline) character. Such texts will be displayed by Gcal in a formatted manner at a left margin, this means, they are lead by a definite number of space characters.

You may depreciate the special meaning of the ‘~’ (tilde) character —in case this character itself is needed— by placing a ‘\’ (backslash) character before it, e.g. ‘\~’. If you need the ‘\~’ characters themselves, you have to protect the ‘\’ (backslash) character by another ‘\’ (backslash) character, e.g. ‘\\~’.

Each time a ‘^’ (caret) character is found in the text part, this character is also replaced by a real ‘\n’ (newline) character. Such texts will be displayed by Gcal at column 1, this means, they are not lead by space characters. The rules for protecting the ‘^’ character are the same as the rules used for protecting the ‘~’ character.

The resource file lbrk-1.rc

     

$ cat lbrk-1.rc -| ; Hi, I'm `lbrk-1.rc' and alive now -| ; -| 0 I know I'm a short text -| 0 I hope I'm long enough~here, a line break-up~\ -| and again~and now for the last time... -| 0 I hope I'm also long enough^here, a line break-up\ -| ~and again^and now for the last time... -| 0 Am I another short text? Dunno...

is displayed as follows:

     

$ gcal %00000101 --resource-file=./lbrk-1.rc --disable-highlighting -| -| Fixed date list: -| -| Sat, Jan 1st 2000: Am I another short text? Dunno... -| Sat, Jan 1st 2000: I hope I'm also long enough -| here, a line break-up -| and again -| and now for the last time... -| Sat, Jan 1st 2000: I hope I'm long enough -| here, a line break-up -| and again -| and now for the last time... -| Sat, Jan 1st 2000: I know I'm a short text

Because whitespace characters are used to separate the date part from the text part52, it is not possible to supply the text part with leading whitespace characters without further ado. If one or more whitespace characters shall lead the text part, this can be arranged by protecting the first of these whitespace characters (and that by placing a ‘\’ (backslash) character before it), e.g. ‘\ ’ if it is a space character. By means of such a character sequence, Gcal notices that the text trailing the ‘\’ character is no longer used for separating purposes, but is member of the text part. Gcal skips this specific, marking backslash character (avoids its output) and processes the rest of the line as usual.

The following example should be enough to elucidate the above facts. The resource file wspc-1.rc

     

$ cat wspc-1.rc -| 0 BANG BANG -| 0 bogus -| 0 bogomips -| 0 \hello world -| 0 \ main(){for(;;)fork();} -| 0 \ sh $0 & $0 & -| 0 \ a \ b \\ c \\\ d -| 0 What happens now?\ -| ~0 \ This! -| 0 What happens now?\\ -| ~0 \ That!

is displayed as follows:

     

$ gcal --resource-file=./wspc-1.rc --disable-highlighting -| -| Fixed date list: -| -| Wed, Jun 14th 2000: sh $0 & $0 & -| Wed, Jun 14th 2000: a \ b \\ c \\\ d -| Wed, Jun 14th 2000: main(){for(;;)fork();} -| Wed, Jun 14th 2000: BANG BANG -| Wed, Jun 14th 2000: What happens now?~0 \ That! -| Wed, Jun 14th 2000: What happens now? -| 0 \ This! -| Wed, Jun 14th 2000: \hello world -| Wed, Jun 14th 2000: bogomips -| Wed, Jun 14th 2000: bogus


Next: , Previous: Text part of a line, Up: Resource file

5.1.5 %?... Special Texts

The text part of a resource file line may be provided with different special texts which may occur in any53 number and order. All these texts start with a ‘%’ (percent) character which may be protected by a leading ‘\’ (backslash) character if the ‘%’ (percent) character itself is wanted to be used in the text part, e.g. ‘\%’. The ‘%’ character is mostly trailed by an optional format instruction, (see Format Instruction, for the detailed description of the format instruction and its components), and then trailed by a distinguishing mark —which defines the kind of the special text to be used— and if it is a letter, Gcal accepts it case-sensitive.

The purpose of these special texts is mainly to suppress output of fixed dates in definite cases, either, or to provide them with particular texts respectively to start external commands. See Description of all %?... Special Texts, for a complete description of all usable special texts, and Summary of all %?... Special Texts, for an according short-list of them.

For example, the resource file speci-1.rc

     

$ cat speci-1.rc -| ; I'm veracious very special :) -| ; -| 0 1. Today is %>1u*K , %>02&*D %U %Y ! -| 0 2. It's the %>03&*N day of the year. -| 0 3. The actual week number is: %k . -| 0 4. Currently, it's %t* o'clock, Mr. %-USER . -| 0 5. Hurry up with your work~\ -| by reason sunrise is at %o+5158+00738+61,2: .

is displayed as follows (in case today's date is the 4th October 1996):

     

$ gcal --resource-file=speci-1.rc -H no -ox -| -| Mon, Oct 4th 1999: 1. Today is MONDAY, 04th October 1999! -| 2. It's the 277th day of the year. -| 3. The actual week number is: 40. -| 4. Currently, it's 06:53pm o'clock, Mr. esken. -| 5. Hurry up with your work -| by reason sunrise is at 07:33.


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5.1.6 Comment line

A line54 beginning with a ‘;’ (semicolon) character in the resource file is treated as a remark and will not be used by Gcal! Any whitespace characters may lead the remark character. See Text part of a line, for information how a NUL character can be used for remarking purposes in a text part.

The following example of the remark.rc resource file —which only consists of remarks— should be enough to elucidate the above facts:

     

$ cat remark.rc -| ;00001031 ^\ -| .......^\ -| ;::;::,^\ -| ;::;::;,^\ -| ;;::;;:;;,^\ -| .vmnv\%vnv\%,.;;;:::;;:;;, .,vnmv\%vnn,^\ -| vmmmn\%vmmnv\%vnmmnv\%;;;;;;\%nmmmnv\%vnmv\%vmmv^\ -| vmmnv\%vmmmnv\%vnmmmmmnv\%;:\%nmmmmmmnv\%vnm\%vnmmmv^\ -| vmmnv\%vmmmnv\%vnmmmmmmmmnv\%nmmmmmmmmnv\%vnmm\%vnmmmv^\ -| vmmnv\%vmmmnv\%vnmmmmmmmmnv\%vmmmmmmmmmmnv\%vnmv\%vnmmmv^\ -| vmmnv\%vmmmnv\%vnmm;mmmmmmnv\%vmmmmmmmm;mmnv\%vnmv\%vnmmmv,^\ -| vmmnv\%vmmmnv\%vnmm;' mmmmmnv\%vmmmmmmm;' mmnv\%vnmv\%vnmmmv,^\ -| vmmnv\%vmmmnv\%vn;; mmmmnv\%vmmmmmm;; nv\%vnmmv\%vnmmmv^\ -| vmmnv\%vmmmmnv\%v;; mmmnv\%vmmmmm;; v\%vnmmmv\%vnmmmv^\ -| vmmnv\%vmmmmnv\%vnmmmmmmmmm;; mmmmmmmmmnv\%vnmmmmv\%vnmmmv^\ -| vmmnv\%vmmmmnv\%vnmmmmmmmmmm;; mmmmmmmmmmnv\%vnmmmmv\%vnmmmv^\ -| vmmnv\%vmmmmnv\%vnmmmmmmmmmmnv;,mmmmmmmmmmmmnv\%vn;mmmv\%vnmmmv^\ -| vmmnv\%vmmm. nv\%vnmmmmmmmmmnv\%;mmmmmmmmmmmnv\%vn; mmmv\%vnmmmv^\ -| `vmmnv\%vmm, v\%vnmmmmmmmmmmnv\%nmmmmmmmmmmnv\%v; mmv\%vnnmmv'^\ -| vmmnv\%vmm;, \%vnmmmmmmmmmnv\%nmmmmmmmmmnv\%;' mv\%vnmmmmv^\ -| vmmnv\%vmm;;, nmmm;' mmmm;;' mv\%vnmmmmv'^\ -| `vmmnv\%vmmm;;,. mmnvv;, mmv\%vnmmmmv'^\ -| `vmmnv\%vmmmmnv\%vnmmmmmmmmnvvnmmmmmmnv\%vnmmmv\%vnmmmmv'^\ -| `vmvn\%vmmmmnv\%vnmmmmmmmnvvnmmmmmnv\%vnmmmm\%vnmmmv'^\ -| `v\%mmmmmn%:\%vnmnmmmmn\%vnmmmnv%:\%vnmv\%nmv' -| -| ; A remarked line -| ; Also a remarked line -| ; A \ -| formatted and multi-line \ -| remark


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5.1.7 Include directives

You may add #include directives in a resource file for searching and loading further resource files55. An #include directive tells Gcal to suspend reading the current resource file and read one other resource file before continuing. The directive is a line in the resource file that looks like this template:

     #include whitespace argument [whitespace] newline

The argument can either be

     "file name"

or56

     <file name>

One whitespace character minimum is required between #include and the argument. The argument may be trailed by extra whitespace characters and the line must always end with a ‘\n’ (newline) character, except it is the last line of a resource file.

Let us inspect a example which is a bit more concrete:

  1. #include "foo/bar"
  2. #include <bar>

The first #include directive tells Gcal to load the file bar in the file directory foo from the actual file directory. If this fails, Gcal tries to load this file by using steps 1...4 of the previously explained mechanism used for searching files (see File searching mechanism).

The second #include directive tells Gcal to load the file bar from the user respectively system data file directory by using steps 3...4 of the previously explained mechanism used for searching files. It is not allowed to include files which have a fixed access path starting from the root file directory by such an #include directive like ‘#include </file> or ‘#include </foo/bar/file>; just as the specification of a single or an extended file name containing a disk/drive specifier57, because the resulting path name58 would not be a valid file name any longer.

Included files may include other files again. But the nesting level of included files is limited on the one hand by the amount of usable working storage of the computer, and on the other hand by the value which is given by the operating system respectively the compiler for the number of files which can be opened simultaneously. Recursive includes59 or cyclic includes60 are not permitted, because such backward references would produce an infinite loop in the program internally! Gcal recognizes such situations and terminates immediately with a fatal error. See Error Code 119, for more information.

If an included resource file cannot be found and no --debug=abort option is given, processing of the resource file containing the #include continues.


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5.1.8 Date variables

Gcal respects global and/or local date variables which may be used either in the date part of a Gcal resource file line, or which may be part of a special text in the text part of a Gcal resource file line. This means, up to 24 user-defined date variables can be set and referenced during program execution. See Fixed date option --date-variable=argument, for more information how global date variables can be used.

A date variable name dvar consists of a single, case-insensitive letter61. In a definition, this name is trailed by the assignment operator character ‘=’, and the numerical values of month mm (or a short, three characters month name, e.g. ‘Jan’, ‘Feb...) and day dd, this variable has to store62, e.g.:

     a=1127
     c=a

stores the 27th November into the local date variable a and into the local date variable c. You should always remember that date variables can only be referenced in a line if they are already defined, because Gcal processes a resource file line by line.

Only local date variables can store dynamical dates given in the mmwwwn, dvar[+|-]n[www] or *d|wn[www] format, e.g.:

     a=03su2
     b=JunMon9
     c=b-3
     d=c+4Sa
     x=*d10
     y=*d10fri
     z=*w3Su

which means, date variable a stores the date of second Sunday in March and b stores date of last Monday in June. The date variable c stores the date which is three days before the date of the last Monday in June and this date is set in the date variable d to that date which is four Saturdays after the date of c. The date variable x stores the date of the 10th absolute day of the year (== 10th January). y stores the date of the 10th Friday of the year, and the assignment to z is the date of the Sunday which occurs in the 3rd week of the year.

Caution:
These kinds of assignments to date variables are only computed correctly in simple year bounds —which means during a current year— and not in fixed dates shown after the current year has changed, e.g. in fiscal years.

Date variables which are defined in a resource file are always local and only respected in this specific file, and that file which is included by it. This means for the included file, that all local variables of the caller are visible. The included file itself may define its own local variables in its own name-space, which are not exported to caller on return. All other definitions of date variables63 are always global. If a resource file line contains a reference to a date variable which is not locally defined in that file, Gcal will try to use the global values held by this variable. If this fails because no global definition of this date variable is given, Gcal will not process this line. If the simple --debug respectively --debug=internal option is given, informational messages for each undefined date variable will be shown on the standard error channel (see Global option --debug=internal). If the --debug=abort option is given, the Gcal program will be aborted with an error code when the first undefined global date variable reference occurs. See Error Code 113, and Global option --debug=abort, for further information.

A local date variable can be deleted. This means, that this date variable is no longer valid in its local scope and be undefined therefore. So it is possible to use its potentially defined global value in succeeding lines if this date variable is referenced there. The following example of the resource file dvar-1.rc elucidates these facts:

     

$ cat dvar-1.rc -| ; dvar-1.rc -| ; -| z=0202 -| 0@z The local assigned date to `z' -| z= -| 0@z The global assigned date to `z' -| z=0404 -| 0@z The local assigned date to `z'

So Gcal creates the following output:

     

$ gcal %1777 -H no -x -v z=1212 -f ./dvar-1.rc -y -| -| Sun, Feb 2nd 1777: The local assigned date to `z' -| Fri, Apr 4th 1777: The local assigned date to `z' -| Fri, Dec 12th 1777: The global assigned date to `z' $ gcal %1777 -H no -x -f ./dvar-1.rc -y -| -| Sun, Feb 2nd 1777: The local assigned date to `z' -| Fri, Apr 4th 1777: The local assigned date to `z'

Only advanced users should apply the --export-date-variables option which causes that the actual incarnation of a local date variable —which was previously defined in a resource file and not in an included file— is being exported to further resource files instead of using its global value, in case that date variable is not locally defined in that further resource file. See Include directives, for more details.

But be aware, the use of this option could create unwanted results, because the order of processing the resource files is an important entity in managing the --export-date-variables option, so it is not recommended to use it. You, the user, must exactly know what you are doing when applying this option; you are expressively warned now!

Some basic operations can be performed on date variables. These are:

Operation Description

dvar++ Simple increment by one day.
dvar-- Simple decrement by one day.
dvar+=[+|-]n Addition of a constant numerical day factor [+|-]n.
dvar-=[+|-]n Subtraction of a constant numerical day factor [+|-]n.
dvar+=nwww Addition of n weekdays www.
dvar-=nwww Subtraction of n weekdays www.

The scope of the operations which are done on a local date variable, is that resource or include file, where the local date variable is defined.

If operations on a global date variable are performed in a resource file or that file which is included by it, these operations are only valid in that specific file64, not in further resource files processed. This means, the initial values of global date variables are always restored if the resource file changes.

Please finally note, that each date variable assignment/operation must be given separately on a single line in the resource file.


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5.1.9 Text variables

Gcal respects global and/or local text variables which may be used anywhere in a line of a Gcal resource file. This means, up to 26 user-defined text variables can be set and referenced during program execution. See Fixed date option --text-variable=argument, for more information how global text variables can be used.

A text variable name tvar consists of the ‘$’ prefix and a single, case-insensitive letter.

A text variable is defined as follows:

Indeed, Gcal executes external commands only if the --execute-command option is given at program start-up. See Fixed date option --execute-command, for more details.

The text which appears at the right side of one of the valid assignment operator characters may reference names of already defined text variables. These references are converted to the according textual values just before the assignment is performed by Gcal. You should always remember that text variables can only be referenced in a line if they are already defined, because Gcal processes a resource file line by line. Gcal always expands text variable references recursively until all sub-references to other text variables are resolved.

Local text variables are set to an empty value and thus defined in a special mode in case no text appears at the right side of one of the valid assignment operator characters.

If a text variable is referenced, an optional format instruction may be specified between the ‘$’ prefix and the single letter (here: the variable name), which makes it possible to modify the representation of the text (here: the contents) at which the text variable points to. Let us assume a resource file by the name of tvarf-1.rc exists with the following contents:

     

$ cat tvarf-1.rc -| ; tvarf-1.rc -| ; -| $a=123 -| $b=$:010*a -| $c=$b -| $b= -| 0 1. \$c=.$c. -| 0 2. \$c=.$:20*c. -| 0 3. \$b=.$>1w*b. -| 0 4. \$a=.$>5#a.

So Gcal creates the following output:

     

$ gcal -Ux --text-variable='$b=XXX YY' --resource-file=./tvarf-1.rc -| -| 1. $c=.0000000123. -| 2. $c=. 0000000123 . -| 3. $b=.Xxx Yy. -| 4. $a=. 123.

See Format Instruction, for the detailed description of the format instruction and its components.

You may depreciate the special meaning of the ‘$’ prefix character —in case this character itself is needed in the text— by placing a ‘\’ (backslash) character before it, e.g. ‘\$’. If you need the ‘\$’ characters themselves in the text, you have to protect the ‘\’ (backslash) character by another ‘\’ (backslash) character, e.g. ‘\\$’.

External commands are not directly executed by Gcal, they are executed by means of the command line interpreter of the operating system, the shell. As consequence to this, of course the commands have to be specified according to the syntax conventions of the used shell, concerning the grouping conventions, list processing conventions, redirection conventions et cetera! For example, it is possible that you have to write ‘$a?(cat text) instead of the simple ‘$a?cat text. See the pertinent literature for more details.

If the output of external commands, which appears on the standard output channel, is assigned to text variables in an interpreted manner, this output is internally directed by Gcal into a temporary file. Thereafter, the contents of the temporary file is transfered to the text variable and the temporary file is removed.

If the output of external commands, which appears on the standard output channel, is assigned to text variables in an uninterpreted manner, this output is internally processed by the Txt2gcal program first (see Invoking txt2gcal), and then this output is directed by Gcal into a temporary file. Thereafter, the contents of the temporary file is transfered to the text variable and the temporary file is removed. In case a TXT2GCALPROG environment variable (see Environment Variable TXT2GCALPROG) is defined and set with the file name of the executable Txt2gcal program, Gcal will use this file name for calling Txt2gcal. Otherwise, the file name txt2gcal —which is burned-in during the compilation step of the Gcal program— is used for calling the Txt2gcal program. The TXT2GCALPROG environment variable must always be set if the Txt2gcal program is installed under another name than the standard name txt2gcal, otherwise Gcal is unable to execute the Txt2gcal program automatically!

If the simple --debug respectively --debug=internal option is given at program start-up, informational messages about the executed command and its exit code will be shown on the standard error channel (see Global option --debug=internal).

If the --debug=abort option is given, the Gcal program will be aborted with an error code in case an exit code not equal zero occurred during the execution of the command. See Error Code 2, and Global option --debug=abort, for further information.

Here is an example which explains how the output of external commands can be assigned to text variables. Supposing there is a resource file by the name of tvarc-1.rc with the following contents:

     

$ cat tvarc-1.rc -| %t $a $>+06*b $>1u*c

This file is used in the resource file tvarc-1a.rc and processed by Gcal as follows:

     

$ cat tvarc-1a.rc -| ; tvarc-1a.rc -| ; -| $a=bonjour -| $b=123 -| $c=bonsoir -| $x?cat $f -| 0 \$x=---$:30*x--- -| $y:cat $f -| 0 \$y=---$y--- -| 0 \$y=:::$>1u*y::: $ gcal -f tvarc-1a.rc -QUx --exe -r'$f=./tvarc-1.rc' -| $x=--- 18:54 bonjour +00123 BONSOIR --- -| $y=---%t $a $>+06*b $>1u*c--- -| $y=:::%T $A $>+06*B $>1U*C:::

Here are some more examples showing how Gcal processes text variables. Let us assume a resource file by the name of tvar-1.rc exists with the following contents:

     

$ cat tvar-1.rc -| ; tvar-1.rc -| ; -| $a=foo -| 0 \$a:1=$a -| $c=$a -| 0 \$c=$c -| $b=$c bar $a -| 0 \$b=$b -| $a=bar $b baz $a booz -| 0 \$a:2=$a -| $a= -| $b=0 $b $c frozz $a frozz -| $b ->That's \$b -| 0 \$x='$x' and \$d is undefined: $d... -| $a= 0 ~ 1~2~\$3~%n~$c~\ -| now it's enough! -| 0 \$a=---$a--- -| $a=0 \ \ \\ And this... -| $a works too!

So Gcal creates the following output:

     

$ gcal %19960101 -H no -x -r '$A=FROBOZZ:$x=' -f ./tvar-1.rc -| -| Mon, Jan 1st 1996: \ \\ And this... works too! -| Mon, Jan 1st 1996: $a:1=foo -| Mon, Jan 1st 1996: $a:2=bar foo bar foo baz foo booz -| Mon, Jan 1st 1996: $a=--- 0 -| 1 -| 2 -| $3 -| 01-Jan-1996 -| foo -| now it's enough!--- -| Mon, Jan 1st 1996: $b=foo bar foo -| Mon, Jan 1st 1996: $c=foo -| Mon, Jan 1st 1996: $x='' and $d is undefined: $d... -| Mon, Jan 1st 1996: foo bar foo foo frozz FROBOZZ frozz ->That's $b

Or a resource file by the name of tvar-2.rc exists with the following contents:

     

$ cat tvar-2.rc -| ; tvar-2.rc -| ; -| $a=$b foo -| $b=0@e -| $a bar -| $b \$b -| 0 \$a:$a -| 0 \$b:$b

So Gcal creates the following output:

     

$ gcal %19960101 -H no -x -f ./tvar-2.rc -| -| Mon, Jan 1st 1996: $a:0@e foo -| Mon, Jan 1st 1996: $b:0@e $ gcal %19960101 -H no -x -f ./tvar-2.rc -y -| -| Sun, Apr 7th 1996: $b -| Sun, Apr 7th 1996: foo bar

As seen before, it is allowed to store complete (or partial) date parts (see Date part of a line), likewise special texts (see %?... Special Texts) into text variables or references to other text variables, which are processed by Gcal after their expansion. See Description of all %?... Special Texts, for limitations concerning the assignment of special texts to text variables.

Text variables which are defined in a resource file are always local and only respected in this specific file, and that file which is included by it. This means for the included file, that all local variables of the caller are visible. The included file itself may define its own local variables in its own name-space, which are not exported to caller on return. All other definitions of text variables65 are always global. If a resource file line contains a reference to a text variable which is not locally defined in that file, Gcal will try to use the global values held by this variable. If this fails because no global definition of this text variable is given, Gcal keeps the name of this text variable untouched in this line, except this text variable held an empty value. In such a case, Gcal completely ignores this text variable while processing and displaying instead of keeping its name untouched in this line.

An example to this. Supposing a resource file by the name of tvar-3.rc exists with the following contents:

     

$ cat tvar-3.rc -| ; tvar-3.rc -| ; -| $c=+00+000 -| $h= -| $d=$c$h -| 0 %o$d %s$d -| 0 \$c=$c \$h=$h \$d=$d \$x=$x

So Gcal creates the following output:

     

$ gcal -QUx -f ./tvar-3.rc -| $c=+00+000 $h= $d=+00+000 $x=$x -| 05:57 18:04 $ gcal -QUx -r '$h=+1000:$x=' -f ./tvar-3.rc -| $c=+00+000 $h=+1000 $d=+00+000+1000 $x= -| 05:52 18:09

Only advanced users should apply the --export-text-variables option which causes that the actual incarnation of a local text variable —which was previously defined in a resource file and not in an included file— is being exported to further resource files instead of using its global value, in case that text variable is not locally defined in that further resource file. See Include directives, for more details.

But be aware, the use of this option could create unwanted results, because the order of processing the resource files is an important entity in managing the --export-text-variables option, so it is not recommended to use it. You, the user, must exactly know what you are doing when applying this option; you are expressively warned now!

Some basic operations can be performed on text variables in case they contain integer values. These are:

Operation Description

tvar++ Simple increment by one.
tvar-- Simple decrement by one.
tvar+=[+|-]n Addition of a constant numerical factor [+|-]n.
tvar-=[+|-]n Subtraction of a constant numerical factor [+|-]n.

Here is an example showing how Gcal processes text variable operations. Let us assume a resource file by the name of tvaro-1.rc exists with the following contents:

     

$ cat tvaro-1.rc -| ; tvaro-1.rc -| ; -| $a=130 -| $b=2 -| 0 1. \$b=$b -| $b++ -| 0 2. \$b=$b -| $b+=7 -| 0 3. \$b=$b -| $b-- -| 0 4. \$b=$b -| $b-=-5 -| 0 5. \$b=$b -| $b+=123 -| 0 6. \$b=$b -| $b-=$a -| 0 7. \$b=$b -| $b-=10000 -| 0 8. \$b=$b -| $b+=10000 -| 0 9. \$b=$b -| $b=02 -| 0 a. \$b=$b -| $b++ -| 0 b. \$b=$b

So Gcal creates the following output:

     

$ gcal -QUx -f ./tvaro-1.rc -| 1. $b=2 -| 2. $b=3 -| 3. $b=10 -| 4. $b=09 -| 5. $b=14 -| 6. $b=137 -| 7. $b=007 -| 8. $b=-9993 -| 9. $b=00007 -| a. $b=02 -| b. $b=03

As you can see in the former example, if operations are made like these, the default behavior of Gcal is to fill with leading zeroes to preserve a former length of a text variable, in case a carry into one of the next decimal places has happened and is taken back by an operation at a later place in the resource file. But this default behavior can be disabled respectively changed by using the already above mentioned format instruction.

The scope of the definitions which are done on a local text variable, is that resource or include file, where the local text variable is defined.

If a global text variable is redefined in a resource file or that file which is included by it, these redefinitions are only valid in that specific file66, not in further resource files processed. This means, the initial values of global text variables are always restored if the resource file changes.

Please finally note, that each text variable assignment/operation must be given separately on a single line in the resource file.


Previous: Resource file, Up: Fixed Dates

5.2 Resource file examples

Here are some examples of problem oriented resource files which might be useful to get a deeper impression about the attributes of Gcal's fixed date feature.

Let us begin with a common example, the resource file common.rc:

     

$ cat common.rc -| ; common.rc, a common example of a resource file. -| ; -| 19940715 Local time: %t --> Dentist at 10:00 -| 00000921 My %B1962 birthday%i1952#2062 -| 0000093 Gregorian~Reformation\~is %y1752 years ago -| 0000Sep03 Gregorian~Reformation\~is %y1752 years ago -| 0 Every day in every month in every year -| 0000 Every day in every month in every year -| 00000000 Every day in every month in every year -| 199400fri Every Friday in 1994 -| 000007mo3 Every third Monday~in July every year less 1980%i#1979 -| 0000@e-10 Easter Sunday-10 days every year -| 0@e-10 Easter Sunday-10 days every year -| 0000@e+10 Easter Sunday+10 days every year -| a=1127 -| 0@a+20 20 days after date of date variable `a' -| a=*W10FR -| 0@a-1 The Thursday of the 10th week every year -| 0@a The Friday of the 10th week every year -| 0@a1 The Saturday of the 10th week every year -| 1995*d10 The 10th absolute day in 1995 -| 1995*d99tue The last Tuesday in 1995 -| 0*w99su The Sunday of the last week every year -| ; -| ; Next entry is respected by ALL fixed date period modifiers. -| ; -| 1994*d1sun#99SUN.7 Each Sunday in 1994 -| ; -| ; Day of Prayer & Repentance is Wednesday before the Sunday, -| ; which is before the 1st Advent's Sunday. -| ; -| a=1225 -| a=a-5sun -| 0@a-4 Day of Prayer & Repentance -| ; or -| 0@a-1wed Day of Prayer & Repentance

And here is a resource file by the name of demo-1.rc, used to detect all Fridays the 13th of a year:

     

$ cat demo-1.rc -| ; demo-1.rc -| ; -| $a=Friday the 13th%i0000 -| $b=#0000 -| $c=fri2 -| $d=fri3 -| 00000113 $a01$c$b01$c -| 00000113 $a01$d$b01$d -| 00000213 $a02$c$b02$c -| 00000213 $a02$d$b02$d -| 00000313 $a03$c$b03$c -| 00000313 $a03$d$b03$d -| 00000413 $a04$c$b04$c -| 00000413 $a04$d$b04$d -| 00000513 $a05$c$b05$c -| 00000513 $a05$d$b05$d -| 00000613 $a06$c$b06$c -| 00000613 $a06$d$b06$d -| 00000713 $a07$c$b07$c -| 00000713 $a07$d$b07$d -| 00000813 $a08$c$b08$c -| 00000813 $a08$d$b08$d -| 00000913 $a09$c$b09$c -| 00000913 $a09$d$b09$d -| 00001013 $a10$c$b10$c -| 00001013 $a10$d$b10$d -| 00001113 $a11$c$b11$c -| 00001113 $a11$d$b11$d -| 00001213 $a12$c$b12$c -| 00001213 $a12$d$b12$d

The result for the years 1996...2002 is as follows:

     

$ gcal -H no -u -x -f ./demo-1.rc 1996+2002 -| -| Fri, Sep 13th 1996: Friday the 13th -| Fri, Dec 13th 1996: Friday the 13th -| -| Fri, Jun 13th 1997: Friday the 13th -| -| Fri, Feb 13th 1998: Friday the 13th -| Fri, Mar 13th 1998: Friday the 13th -| Fri, Nov 13th 1998: Friday the 13th -| -| Fri, Aug 13th 1999: Friday the 13th -| -| Fri, Oct 13th 2000: Friday the 13th -| -| Fri, Apr 13th 2001: Friday the 13th -| Fri, Jul 13th 2001: Friday the 13th -| -| Fri, Sep 13th 2002: Friday the 13th -| Fri, Dec 13th 2002: Friday the 13th

Or a bit shorter version of the resource file demo-1.rc by the name of demo-2.rc, likewise used to detect all Fridays the 13th of a year, and that by using the fact, that a Friday the 13th only occurs if the first day of a month is a Sunday:

     

$ cat demo-2.rc -| ; demo-2.rc -| ; -| $a=%n+12 is a Friday%i0000 -| $b=#0000 -| $c=sun1 -| 00000101 $a01$c$b01$c -| 00000201 $a02$c$b02$c -| 00000301 $a03$c$b03$c -| 00000401 $a04$c$b04$c -| 00000501 $a05$c$b05$c -| 00000601 $a06$c$b06$c -| 00000701 $a07$c$b07$c -| 00000801 $a08$c$b08$c -| 00000901 $a09$c$b09$c -| 00001001 $a10$c$b10$c -| 00001101 $a11$c$b11$c -| 00001201 $a12$c$b12$c

The result for the years 1996...2002 is as follows:

     

$ gcal -H no -u -x -f ./demo-2.rc 1996+2002 -| -| Sun, Sep 1st 1996: 13-Sep-1996 is a Friday -| Sun, Dec 1st 1996: 13-Dec-1996 is a Friday -| -| Sun, Jun 1st 1997: 13-Jun-1997 is a Friday -| -| Sun, Feb 1st 1998: 13-Feb-1998 is a Friday -| Sun, Mar 1st 1998: 13-Mar-1998 is a Friday -| Sun, Nov 1st 1998: 13-Nov-1998 is a Friday -| -| Sun, Aug 1st 1999: 13-Aug-1999 is a Friday -| -| Sun, Oct 1st 2000: 13-Oct-2000 is a Friday -| -| Sun, Apr 1st 2001: 13-Apr-2001 is a Friday -| Sun, Jul 1st 2001: 13-Jul-2001 is a Friday -| -| Sun, Sep 1st 2002: 13-Sep-2002 is a Friday -| Sun, Dec 1st 2002: 13-Dec-2002 is a Friday

Of course, preceding textual expense for the purpose of detecting all Fridays the 13th of a year can be dramatically reduced by simply using of

     0*d1fri#99fri.7 Friday the 13th%i00000013#00000013

in the resource file demo-1.rc, respectively,

     0*d1sun#99sun.7 %n+12 is a Friday%i00000001#00000001

in the demo-2.rc resource file.

On the one hand, preceding one-liners reduce the coding expense quite considerably —from 28 respectively 15 lines to 1 line in each case—, but on the other hand, this partly increases the checking expense of these one-liners considerably and result in a longer program run-time therefore. Both one-liners produce about 52 internal productions respectively effective fixed date entries of themselves for each year checked by Gcal, at which the demo-1.rc and demo-2.rc resource files cause 24 respectively 12 effective fixed date entries only.

And here is a resource file by the name of demo-3.rc, used to detect all working-days of any month:

     

$ cat demo-3.rc -| ; demo-3.rc -| ; -| $a=%VWork day -| $c=%i#0000$b99 -| a=$bmon1 -| 0@a#+4 $a -| a=$btue1 -| 0@a#+3 $a -| a=$bwed1 -| 0@a#+2 $a -| a=$bthu1 -| 0@a#+1 $a -| a=$bfri1 -| 0@a $a -| a=$bmon2 -| 0@a#+4 $a -| a=$bmon3 -| 0@a#+4 $a -| a=$bmon4 -| 0@a#+4 $a$c -| a=$bmon9 -| 0@a#+4 $a$c

Respectively a bit shorter version of the resource file demo-3.rc:

     ; demo-3.rc
     ;
     $a=%VWork day
     $c=%i#0000$b99
     0000$bmon1:5 $a
     0000$btue1:4 $a
     0000$bwed1:3 $a
     0000$bthu1:2 $a
     0000$bfri1:1 $a
     0000$bmon2:5 $a
     0000$bmon3:5 $a
     0000$bmon4:5 $a$c
     0000$bmon9:5 $a$c

And a resource file by the name of include.rc exists which is only used to include one given resource file:

     

$ cat include.rc -| #include "$f"

Then the result for the month August 1996 is as follows:

     

$ gcal -H no -u -x -r '$b=08:$f=demo-3.rc' -f ./include.rc Aug 1996 -| -| Thu, Aug 1st 1996: Work day -| Fri, Aug 2nd 1996: Work day -| Mon, Aug 5th 1996: Work day -| Tue, Aug 6th 1996: Work day -| Wed, Aug 7th 1996: Work day -| Thu, Aug 8th 1996: Work day -| Fri, Aug 9th 1996: Work day -| Mon, Aug 12th 1996: Work day -| Tue, Aug 13th 1996: Work day -| Wed, Aug 14th 1996: Work day -| Thu, Aug 15th 1996: Work day -| Fri, Aug 16th 1996: Work day -| Mon, Aug 19th 1996: Work day -| Tue, Aug 20th 1996: Work day -| Wed, Aug 21st 1996: Work day -| Thu, Aug 22nd 1996: Work day -| Fri, Aug 23rd 1996: Work day -| Mon, Aug 26th 1996: Work day -| Tue, Aug 27th 1996: Work day -| Wed, Aug 28th 1996: Work day -| Thu, Aug 29th 1996: Work day -| Fri, Aug 30th 1996: Work day

And of course, the preceding textual expense for the purpose of detecting all work days of any month can be dramatically reduced by simply using of

     00000001#0099 %V%rWork day

in the resource file demo-3.rc.

And next the resource file by the name of sun-1.rc which detects the actual local time, the approximate time of sunrise and sunset, day and night length of two geographic locations:

     

$ cat sun-1.rc -| ; sun-1.rc, comparison of sunrise / sunset, day length and night -| ; length of two locations, namely: Muenster.DE / Bangkok.TH -| ; All references are based on Muenster.DE ! -| ; -| ; Common definitions -| $p=0*d1#999 -| $v=%2%4 for that places local time -| $z=actual local time in -| ; Definitions for winter time -| $a=%e#1980 %e0@a#0@b-1 -| $x=Sun:~%o$c,$w rise, %s$c,$w set, %u$c,$w day, %z$c,$w night~$l -| ; Winter time in Germany == CEWT/GMT-1 (+60 minutes) -| $w=+60 -| ; Starting date of winter time in Germany -| b=10sun9 -| ; Definitions for summer time (daylight-saving time) -| $b=%e#1980 %i0@a#0@b-1 -| $y=Sun:~%o$c,$s rise, %s$c,$s set, %u$c,$s day, %z$c,$s night~$l -| ; Summer time in Germany == CEST/GMT-2 (+120 minutes) -| $s=+120 -| ; Starting date of summer time in Germany -| a=03sun9 -| ; Geographic co-ordinate and name of the location Muenster, Germany -| $c=+5158+00738+61 -| $l=%1Muenster -| ; Muenster's local time sunrise etc. for that places local time -| $p $a $x$v -| $p $b $y$v -| ; Muenster's actual local time -| 0 $a %1%@$w %2 $z $l -| 0 $b %1%@$s %2 $z $l -| ; Geographic co-ordinate and name of the location Bangkok, Thailand -| $c=+1345+10031+10 -| $l=%3Bangkok%4-time converted to $l's%2 local time -| ; Bangkok's sunrise etc. based on Muenster's local time -| $p $a $x -| $p $b $y -| ; Bangkok's local time == WAST/GMT-7 (+420 minutes) -| $t=+420 -| $w=$t -| ; Bangkok's actual local time -| $l=%3Bangkok -| 0 $a %3%@$t %4 $z $l -| 0 $b %3%@$t %4 $z $l -| ; Bangkok's sunrise etc. for that places local time -| $l=$l$v -| $p $x

The result for the 12th September 1999 is as follows:

     

$ gcal -fsun-1.rc -Ux -Hno -| -| 18:53/12-Sep-1999 actual local time in Muenster -| 23:53/12-Sep-1999 actual local time in Bangkok -| Sun: -| 01:06rise, 13:22set, 12h16'day, 11h44'night -| Bangkok-time converted to Muenster's local time -| Sun: -| 06:06rise, 18:22set, 12h16'day, 11h44'night -| Bangkok for that places local time -| Sun: -| 06:56rise, 19:54set, 12h58'day, 11h02'night -| Muenster for that places local time

The next example is the resource file redir-1.rc which demonstrates the use of the shell command %![argument] special text:

     

$ cat redir-1.rc -| ; redir.rc, run shell command $c and redirect it to $f -| ; -| $p=0*d1#999 -| $c=$p %!$c -| $g=|txt2gcal - $p -| ; -| $c $g>$f

The result of succeeding call of Gcal, to which you can also add the --debug=all option for a better understanding of the execution methods, is as follows:

     

$ gcal --exe -QUx -f./redir-1.rc+XX -r'$f=XX:$c=echo $f' -#'0 %!rm $f' -| XX

And finally a resource file by the name of swtim-1.rc which produces fixed date messages reminding Daylight Saving that are valid since 1981 for the Federal Republic of Germany67.

     

$ cat swtim-1.rc -| ; swtim-1.rc, daylight-saving time BRD -| ; -| $a=daylight-saving time starts Sunday -| ; -| a=03sun9 -| 0@a-2#+2 Summer $a~+1 hrs. (02:00 --> 03:00 h.)%i1981 -| ; -| a=09sun9 -| 0@a-2#+2 Winter $a~-1 hrs. (03:00 --> 02:00 h.)%i1981#1995 -| ; -| a=10sun9 -| 0@a-2#+2 Winter $a~-1 hrs. (03:00 --> 02:00 h.)%i1996

The result for the year 1998 is as follows:

     

$ gcal %1998 -Hno -xy -f ./swtim-1.rc -| -| Fri, Mar 27th 1998: Summer daylight-saving time starts Sunday -| +1 hrs. (02:00 --> 03:00 h.) -| Sat, Mar 28th 1998: Summer daylight-saving time starts Sunday -| +1 hrs. (02:00 --> 03:00 h.) -| Sun, Mar 29th 1998: Summer daylight-saving time starts Sunday -| +1 hrs. (02:00 --> 03:00 h.) -| Mon, Mar 30th 1998: Summer daylight-saving time starts Sunday -| +1 hrs. (02:00 --> 03:00 h.) -| Tue, Mar 31st 1998: Summer daylight-saving time starts Sunday -| +1 hrs. (02:00 --> 03:00 h.) -| Fri, Oct 23rd 1998: Winter daylight-saving time starts Sunday -| -1 hrs. (03:00 --> 02:00 h.) -| Sat, Oct 24th 1998: Winter daylight-saving time starts Sunday -| -1 hrs. (03:00 --> 02:00 h.) -| Sun, Oct 25th 1998: Winter daylight-saving time starts Sunday -| -1 hrs. (03:00 --> 02:00 h.) -| Mon, Oct 26th 1998: Winter daylight-saving time starts Sunday -| -1 hrs. (03:00 --> 02:00 h.) -| Tue, Oct 27th 1998: Winter daylight-saving time starts Sunday -| -1 hrs. (03:00 --> 02:00 h.)


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Appendix A Genesis of the Gregorian Calendar

The nowadays calendar was first formulated in several inaccurate variations by the Romans based on methods developed by the Babylonians and Egyptians. The aim of all these calendars was to harmonize the cycles of the Moon and the Sun. During Julius Caesar's reign, January was falling in autumn so he ordered Sosigenes to make changes to the calendar. He added 90 days to the year 46 BC to make up for the seasonal drift and adjusted the lengths of the months similarly as we know them to be today. He introduced the leap year by adding one day to February every four years. For the present, the leap year regulation was made in the way that all four years after the 23rd day in February a leap day was laid in, so the 24th February occurred twice. The use of the leap year was an improvement but not entirely accurate.

But in the later years, the leap rule was used in the wrong way so that the errors are corrected by emperor Augustus in the year 8 BC. A curious sequel happened on this occasion. Because Augustus reacted with great jealousy to all things previously made and propagated by Julius Caesar, he did not like Caesar's name in the calendar, namely the today's month of July. Offhandedly he ordered to name another month to himself and so the month name August arose. Furthermore, Augustus did not tolerate the fact that his month of birth (the August) was shorter than Caesar's month in the sense of the periodical sequence of months with 30 and 31 days. Consequently, the month of August got 31 days, too. Due to this modification, the number of days in February were reduced to 28 and 29 days, respectively, so the 29th February was designed to be the leap day now.

This calendar is well known under the term Julian calendar and is based on a plain solar year. The nominal length of a solar year (respectively a so-called tropical year) is 365 days, 5 hours, 48 minutes, and 46 seconds. One 366-day year every four years equates to an average Julian year of 365 days and 6 hours, consequently to 365.25 days. This means, every four years, an error of 44 minutes, 56 seconds was accumulated by this kind of calendar calculation. Because of this counting method, the length of the years becomes a bit too long, by more than 11 minutes.

By the 16th century, the vernal equinox occurred around March 11, rather than March 21, by reason of an accumulated error of ten days. The feast of Easter shifted away more and more from the habitual vernal date, which must have always been celebrated on an earlier date. So Pope Gregory XIII introduced the new style calendar in 1582. Thursday, the 4th October 1582, was followed by Friday, the 15th October, by suppressing the ten days between both dates. Moreover, he ordained that years ending in hundreds should not be leap years unless they are divisible by 400. Incidentally, the Gregorian reform compensates by 72 hours (3 days) every 400 years. The actual excess accumulated is 74 hours, 53 minutes and 20 seconds. The error of 2 hours, 53 minutes and 20 seconds every 400 years accumulates to one day in about 3300 years. Thereby, the Gregorian year has an average length of 365.2425 days.

But this Gregorian calendar was accepted very slowly by others. Catholic countries adopted the Gregorian calendar almost immediately. Most Protestant countries on the Continent adopted the new calendar around 1700. England and the American colonies changed in 1752, by act of Parliament. Orthodox Christian countries adopted the Gregorian calendar later. Russia was the last European country to do so, after the communist revolution of 1917. As a result, the former U.S.S.R. celebrated the October Revolution (happened on October 25th, 1917) in the old style calendar on November 7th.

The era of a world wide uniform calendar is already part of history today. The Iran returned to the traditional Mohammedan lunar calendar in 1979 after removal of the Shah reign. There are some efforts to improve our currently valid Gregorian calendar. Its disadvantages are the reason why an appointed day is not always on the same week day. Besides, the month lengths are not equal and the holidays, which have relations to the feast of Easter, are moved within the calendar from one year to another. A very sophisticated suggestion was proposed by the United Nations, but the international establishment of this suggestions has failed, since it was resisted by some countries as well as the churches.


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Appendix B Gcal Utilities

Three small utility programs are part of the Gcal 3.6 package. The Tcal program runs the Gcal program with the date set one day ahead. The Txt2gcal program creates a verbatim Gcal resource file from a text file, and in contrast to this, the Gcal2txt program creates a verbatim text file from a Gcal resource file.


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B.1 Invoking tcal

The Tcal program runs the Gcal program with the date of tomorrow's day68. Its arguments are as follows:

     tcal [--help | --version] | [--shift=[+|-]number] [argument...]

All given arguments are passed unmodified to the Gcal program. If the Gcal program shall be called with another date than tomorrow's date, this desired date can be selected by using the --shift=[+|-]number option, in which [+|-]number is the distance of days the desired date is distant from the actual system date (==today). (Works only for Gregorian years.) The --shift option must be given before all other arguments that are passed to the Gcal program.

In case a GCALPROG environment variable (see Environment Variable GCALPROG) is defined and set with the file name of the executable Gcal program, Tcal will use this file name for calling Gcal. Otherwise, the file name gcal —which is burned-in during the compilation step of the Tcal program— is used for calling the Gcal program. The GCALPROG environment variable must always be set if the Gcal program is installed under another name than the standard name gcal, otherwise Tcal is unable to execute the Gcal program automatically! An exit status of 0 means all processing is successfully done, any other value means an error has occurred.

The program accepts the following options:

--help
Print a usage message listing all available options, then exit successfully.
--version
Print the version number, then exit successfully.
--shift=[+|-]number
Define the displacement in ‘[+|-]number’ days the desired date is distant from the actual date.


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B.2 Invoking txt2gcal

The Txt2gcal program creates a verbatim Gcal resource file from a text file. Its arguments are as follows:

     txt2gcal [--help | --version] | [text-file|-] [date-part]

If no text-file argument is given or/but a single ‘-’ character, the program reads and processes all input received from the standard input channel. If no date-part argument is given, Txt2gcal creates a ‘0’ for the date part. All results are always shown on the standard output channel. An exit status of 0 means all processing is successfully done, any other value means an error has occurred.

The program accepts the following options:

--help
Print a usage message listing all available options, then exit successfully.
--version
Print the version number, then exit successfully.

Here comes an example how to use Txt2gcal. Let us suppose there is a text file by the name of tdemo-1.txt with the following contents:

     

$ cat tdemo-1.txt -| Hi friends, -| -| I'm the demo text containing funny characters and character -| sequences like ~~ \~ % %% $a $1 %%%\ -| %\ %s %%foo %bar \%Baz \\~ \~\ and so on... -| I'm be anxious how I'll be transformed by `txt2gcal'. -|

and Txt2gcal processes this file, redirecting the output to tdemo-1.rc:

     

$ txt2gcal tdemo-1.txt 0*d1#999 > tdemo-1.rc $ cat tdemo-1.rc -| 0*d1#999 \ Hi friends,~\ -| ~\ -| I'm the demo text containing funny characters and character~\ -| sequences like \~\~ \\~ % %% \$a $1 %%%\ ~\ -| %\ \%s %\%foo \%bar \\%Baz \\\~ \\~\ and so on...~\ -| I'm be anxious how I'll be transformed by `txt2gcal'.~\

then Txt2gcal has now created a new Gcal resource file tdemo-1.rc from the text file tdemo-1.txt. Let us finally see, how Gcal will interpret this new resource file:

     

$ gcal %19960101 -H no -Ax -f ./tdemo-1.rc -| -| Mon, Jan 1st 1996: -| Hi friends, -| -| I'm the demo text containing funny characters and character -| sequences like ~~ \~ % %% $a $1 %%%\ -| %\ %s %%foo %bar \%Baz \\~ \~\ and so on... -| I'm be anxious how I'll be transformed by `txt2gcal'. -|


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B.3 Invoking gcal2txt

The Gcal2txt program creates a verbatim text file from a Gcal resource file. Its arguments are as follows:

     gcal2txt [--help | --version] | [resource-file|-]

If no resource-file argument is given or/but a single ‘-’ character, the program reads and processes all input received from the standard input channel. All results are always shown on the standard output channel. An exit status of 0 means all processing is successfully done, any other value means an error has occurred.

The sense and purpose of Gcal2txt is to retrieve all additional texts, which are put into the output by means of the Txt2gcal program.

The program accepts the following options:

--help
Print a usage message listing all available options, then exit successfully.
--version
Print the version number, then exit successfully.

Here comes an example how to use Gcal2txt. For that purpose, let us use the resource file tdemo-1.rc of the previous section (see Invoking txt2gcal), which was created by means of the Txt2gcal program from a text file and which looks like this:

     

$ txt2gcal tdemo-1.txt 0*d1#999 > tdemo-1.rc $ cat tdemo-1.rc -| 0*d1#999 \ Hi friends,~\ -| ~\ -| I'm the demo text containing funny characters and character~\ -| sequences like \~\~ \\~ % %% \$a $1 %%%\ ~\ -| %\ \%s %\%foo \%bar \\%Baz \\\~ \\~\ and so on...~\ -| I'm be anxious how I'll be transformed by `txt2gcal'.~\

Now let us see, how this resource file will be processed by Gcal2txt:

     

$ gcal2txt tdemo-1.rc -| Hi friends, -| -| I'm the demo text containing funny characters and character -| sequences like ~~ \~ % %% $a $1 %%%\ -| %\ %s %%foo %bar \%Baz \\~ \~\ and so on... -| I'm be anxious how I'll be transformed by `txt2gcal'.


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Appendix C Aspects in Internationalization

Starting with version 2.00, Gcal is able to display message texts using any native languages instead of using the English language only, because parts of the GNU gettext package are integrated into the Software. See Introduction, for more details.

By default, Gcal displays all message texts using the English native language in case no other native language is wanted. A so-called message catalog is read by Gcal at run-time if message texts from another native language are required. Gcal 3.6 supports the following native languages:

Native Language Language Code

English en
German de
French fr
Dutch nl
Polish pl
Russian ru
Swedish sv

It is only necessary to set one of the environment variables69:

1. LANGUAGE
2. LC_ALL
3. LC_MESSAGES
4. LANG

with a language code to select another native language instead of the English native language.

Normally, users only have to set the LANG environment variable to tell Gcal the native language to use at run-time level. Presuming users want to run Gcal using the German native language for displaying message texts, they merely have to execute ‘setenv LANG de (in csh) or ‘export LANG; LANG=de (in sh) at the shell prompt. Of course they could even do this from their .login or .profile file. See The User's View, for more details.

As shown above, a simple setting of de in the environment variable LANG is sufficient to enable German message texts. de is the two-letter language code for the German language defined in the ISO-639:1988, and is called simple language code information in the further context. Other language codes can be taken from this ISO-document70.

Because Gcal as calendar program must also comply the specifics of a used native language concerning the ordering of day, month and year (and further things) of a displayed date, the period of Gregorian Reformation, the type of week number and the representation of calendar sheets, these criteria are likewise bound to the language code71.

A en language code causes the following internal defaults of above criteria:

And a de language code72 causes the following internal defaults:

Remember, all these internal defaults are modifiable by the options --date-format, --gregorian-reform, --starting-day, --iso-week-number and --type.

If no language code is detected, Gcal takes the internal defaults of the en language code73.

If a language code is specified for which no message catalog is installed, Gcal takes the internal defaults of the de language code, but displays the message texts using the English native language. Actually, this behavior seems to me the most proper solution in such a case. The English native language is spoken all over the world unlike the German or other native languages, so it is wise to use it here. But the other criteria bound to the English native language are so special for users of other native languages, that it is wise to use the criteria taken for internal defaults of the de language code, because most European countries (taken as standard) essentially use them.

Now British users will certainly ask whether they could use their date format as an internal default74. The answer to this is a simple yes, nevertheless, these users have to set the environment variable LANG with an extended language code information instead of a simple language code information.

The usual template of an extended language code information is as follows:

Both syntaxes contain the language and territory components, which are used by Gcal to select the native language and the other criteria. The language component is equivalent to the simple language code information and the territory component is a two-letter territory or country code as defined by the ISO-3166 like ‘GB’ for Great Britain or ‘US’ for the U.S.A. See the pertinent literature for more details. So British users only have to set the LANG environment variable with a en_GB contents, and after that, they can use the British date format as an internal default.


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Appendix D Metasymbols

Within this document, the following metasyntactic conventions will be used when discussing command line options, commands, arguments and templates:

n
Argument is not optional and n must be a valid number.
e|t|dvar
Argument is not optional and must be a single alphabetic character.
$tvar
Argument is not optional and must be a single alphabetic character, that is lead by a ‘$’ character.
[text]
Argument is optional and text is a valid string of text.
[ab]
Arguments are optional, any number may be used in any order, e.g.:
          NOTHING, a, b, ab, ba ...

{ab}
Arguments are not optional, minimum one up to any number may be used in any order, e.g.:
          a, b, ab, ba ...

[a|b]
Arguments are optional, select either a or b, but not both.
a|b
Arguments are not optional, select either a or b, but not both.
[a[b]]
Arguments are optional, select either a or ab, but not b.
[a|b[c]]
Arguments are optional, select a or b or ac or bc, but not c.
[a|bc]
Arguments are optional, select either ac or bc, but not a or b or c.
[a]|[b]
Argument lists are optional, select either list a or list b, but not both.
[...]
Additional arguments/files may be specified and are optional.


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Appendix E Regular Expressions

This appendix is derived from the gawk-3.0.0 and regex-0.12 manuals.

A regular expression, or regexp, is a way of describing a set of strings. The simplest regular expression is a sequence of letters, numbers, or both. Such a regexp matches any string that contains that sequence. Thus, the regexp ‘foo’ matches any string containing ‘foo’. Other kinds of regular expressions let you specify more complicated classes of strings.

Gcal uses exactly one of the following regular expression programming libraries respectively methods, and that in the decreasing priority how it is chosen at configuration time, or better, compile time of the software:

No. Function Symbol

1. GNU re_compile_pattern() and regex.h GNU-REGEX
2. POSIX regcomp() and regex.h POSIX-REGEX
3. BSD re_comp() BSD-REGEX
4. System V regcmp() SysV-REGEX
5. Henry Spencer V8 regcomp() and regexp.h V8-REGEX
6. Pattern matching is supported, but without metacharacters NO-REGEX

Try ‘gcal --version for detecting the kind of regular expression programming library respectively method that is burned-in in your Gcal program!


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E.1 How to Use Regular Expressions

A regular expression can be used as a pattern if Gcal's --filter-text=pattern option is specified at program start-up.

See Fixed date option --filter-text=pattern, for more details.

Then the regular expression is tested against the entire, completely expanded text of each valid fixed date, and the fixed date is only displayed in case the pattern matches the text75.


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E.2 Regular Expression Operators

You can combine regular expressions with the following characters, called regular expression operators, or metacharacters, to increase the power and versatility of regular expressions.

Here is a table of these metacharacters. All characters that are not listed in the table stand for themselves.

\
This is used to suppress the special meaning of a character when matching. For example:
          \$

matches the character ‘$’.

^
This matches the beginning of a string. For example:
          ^@chapter

matches the ‘@chapter’ at the beginning of a string, and can be used to identify chapter beginnings in Texinfo source files. The ‘^’ is known as an anchor, since it anchors the pattern to matching only at the beginning of the string.

$
This is similar to ‘^’, but it matches only at the end of a string. For example:
          p$

matches a string that ends with a ‘p’. The ‘$’ is also an anchor.

.
The period, or dot, matches any single character. For example:
          .P

matches any single character followed by a ‘P’ in a string. Using concatenation we can make a regular expression like ‘U.A, which matches any three-character sequence that begins with ‘U’ and ends with ‘A’.

[...]
This is called a character list. It matches any one of the characters that are enclosed in the square brackets. For example:
          [MVX]

matches any one of the characters ‘M’, ‘V’, or ‘X’ in a string.

Ranges of characters are indicated by using a hyphen between the beginning and ending characters, and enclosing the whole thing in brackets. For example:

          [0-9]

matches any digit. Multiple ranges are allowed. E.g., the list [A-Za-z0-9] is a common way to express the idea of “all alphanumeric characters.”

To include one of the characters ‘\’, ‘]’, ‘-’ or ‘^’ in a character list, put a ‘\’ in front of it. For example:

          [d\]]

matches either ‘d’, or ‘]’.

Character classes are a new feature introduced in the POSIX standard. A character class is a special notation for describing lists of characters that have a specific attribute, but where the actual characters themselves can vary from country to country and/or from character set to character set. For example, the notion of what is an alphabetic character differs in the U.S.A. and in France.

A character class is only valid in a regexp inside the brackets of a character list. Character classes consist of ‘[:’, a keyword denoting the class, and ‘:]’. Here are the character classes defined by the POSIX standard:

[:alnum:]
Alphanumeric characters.
[:alpha:]
Alphabetic characters.
[:blank:]
Space and tab characters.
[:cntrl:]
Control characters.
[:digit:]
Numeric characters.
[:graph:]
Characters that are printable and are also visible76.
[:lower:]
Lower-case alphabetic characters.
[:print:]
Printable characters77.
[:punct:]
Punctuation characters78.
[:space:]
Space characters79.
[:upper:]
Upper-case alphabetic characters.
[:xdigit:]
Characters that are hexadecimal digits.

For example, before the POSIX standard, to match alphanumeric characters, you had to write [A-Za-z0-9]. If your character set had other alphabetic characters in it, this would not match them. With the POSIX character classes, you can write [[:alnum:]], and this will match all the alphabetic and numeric characters in your character set.

Two additional special sequences can appear in character lists. These apply to non-ascii character sets, which can have single symbols (called collating elements) that are represented with more than one character, as well as several characters that are equivalent for collating, or sorting, purposes. (E.g., in French, a plain ‘e’ and a grave-accented ‘è’ are equivalent.)

Collating Symbols
A collating symbol is a multi-character collating element enclosed in ‘[.’ and ‘.]’. For example, if ‘ch’ is a collating element, then [[.ch.]] is a regexp that matches this collating element, while [ch] is a regexp that matches either ‘c’ or ‘h’.
Equivalence Classes
An equivalence class is a list of equivalent characters enclosed in ‘[=’ and ‘=]’. Thus, [[=eè=]] is a regexp that matches either ‘e’ or ‘è’.

These features are very valuable in non-English speaking locales.

Caution:
The library functions that Gcal uses for regular expression matching currently only recognize POSIX character classes (possibly); they do not recognize collating symbols or equivalence classes.

[^ ...]
This is a negated character list respectively complemented character list. The first character after the ‘[must be a ‘^’. It matches any characters except those in the square brackets. For example:
          [^0-9]

matches any character that is not a digit.

|
This is the alternation operator, and it is used to specify alternatives. For example:
          ^P|[0-9]

matches any string that matches either ‘^P’ or ‘[0-9]. This means it matches any string that starts with ‘P’ or contains a digit.

The alternation applies to the largest possible regexps on either side. In other words, ‘|’ has the lowest precedence of all the regular expression operators.

(...)
Parentheses are used for grouping in regular expressions as in arithmetic. They can be used to concatenate regular expressions containing the alternation operator, ‘|’. For example, ‘@(samp|code)\{[^}]+\} matches both ‘@code{foo} and ‘@samp{bar}. (These are Texinfo formatting control sequences.)
*
This symbol means that the preceding regular expression is to be repeated as many times as necessary to find a match. For example:
          ph*

applies the ‘*’ symbol to the preceding ‘h’ and looks for matches of one ‘p’ followed by any number of ‘h’s. This will also match just ‘p’ if no ‘h’s are present.

The ‘*’ repeats the smallest possible preceding expression. (Use parentheses if you wish to repeat a larger expression.) It finds as many repetitions as possible. For example:

          gcal --filter-text='\(c[ad][ad]*r x\)' -f sample.rc -y

prints every fixed date in sample.rc containing a fixed date text of the form ‘(car x), ‘(cdr x), ‘(cadr x), and so on. Notice the escaping of the parentheses by preceding them with backslashes.

+
This symbol is similar to ‘*’, but the preceding expression must be matched at least once. This means that:
          wh+y

would match ‘why and ‘whhy but not ‘wy, whereas ‘wh*y would match all three of these strings. This is a simpler way of writing the last ‘*’ example:

          gcal --filter-text='\(c[ad]+r x\)' -f sample.rc -y

?
This symbol is similar to ‘*’, but the preceding expression can be matched either once or not at all. For example:
          fe?d

will match ‘fed and ‘fd, but nothing else.

{n}
{n,}
{n,m}
One or two numbers inside braces denote an interval expression which is available in the POSIX standard. If there is one number in the braces, the preceding regexp is repeated n times. If there are two numbers separated by a comma, the preceding regexp is repeated n to m times. If there is one number followed by a comma, then the preceding regexp is repeated at least n times.
wh{3}y
matches ‘whhhy but not ‘why or ‘whhhhy.
wh{3,5}y
matches ‘whhhy or ‘whhhhy or ‘whhhhhy, only.
wh{2,}y
matches ‘whhy or ‘whhhy, and so on.

GNU software that deals with regular expressions provides a number of additional regexp operators. These operators are described here.

Most of the additional operators are for dealing with word matching. For our purposes, a word is a sequence of one or more letters, digits, or underscores (‘_’).

\w
This operator matches any word-constituent character, i.e. any letter, digit, or underscore. Think of it as a short-hand for [A-Za-z0-9_] or [[:alnum:]_].
\W
This operator matches any character that is not word-constituent. Think of it as a short-hand for [^A-Za-z0-9_] or [^[:alnum:]_].
\<
This operator matches the empty string at the beginning of a word. For example, \<away matches ‘away’, but not ‘stowaway’.
\>
This operator matches the empty string at the end of a word. For example, stow\> matches ‘stow’, but not ‘stowaway’.
\b
This operator matches the empty string at either the beginning or the end of a word (the word boundary). For example, ‘\bballs?\b’ matches either ‘ball’ or ‘balls’ as a separate word.
\B
This operator matches the empty string within a word. In other words, ‘\B’ matches the empty string that occurs between two word-constituent characters. For example, \Brat\B matches ‘crate’, but it does not match ‘dirty rat’. ‘\B’ is essentially the opposite of ‘\b’.

There are two other operators that work on buffers. In Emacs, a buffer is, naturally, an Emacs buffer. For other programs, the regexp library routines that Gcal uses consider the entire string to be matched as the buffer80.

For Gcal, since ‘^’ and ‘$’ always work in terms of the beginning and end of strings, these operators do not add any new capabilities. They are provided for compatibility with other GNU software.

\`
This operator matches the empty string at the beginning of the buffer.
\'
This operator matches the empty string at the end of the buffer.

In regular expressions, the ‘*’, ‘+’, and ‘?’ operators, as well as the braces ‘{’ and ‘}’, have the highest precedence, followed by concatenation, and finally by ‘|’. As in arithmetic, parentheses can change how operators are grouped.

Case is normally significant in regular expressions, both when matching ordinary characters (i.e. not metacharacters), and inside character sets. Thus a ‘w’ in a regular expression matches only a lower-case ‘w’ and not an upper-case ‘W’.

The simplest way to do a case-independent match is to use a character list: ‘[Ww]. However, this can be cumbersome if you need to use it often; and unfortunately, it can make the regular expressions harder to read. Supplying a want, Gcal offers the --ignore-case option which ignores all case distinctions in both the regular expression and the completely expanded text of each valid fixed date. See Fixed date option --ignore-case.


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Appendix F Summary of all Regular Expressions

Regular expressions are based on POSIX EREs (Extended Regular Expressions). Regexps are composed of characters. Here is a short-list of them all:

c
matches the character c (assuming c is none of the characters listed below).
\c
matches the literal character c.
.
matches any character.
^
matches the beginning of a string.
$
matches the end of a string.
[abc...]
matches any of the characters abc... (character list).
[[:keyword:]]
matches any character in the character class keyword. Allowable classes are alnum, alpha, blank, cntrl, digit, graph, lower, print, punct, space, upper, and xdigit.
[[.element.]]
matches the multi-character collating element. Gcal does not currently support collating symbols.
[[=list=]]
matches any of the equivalent characters in list. Gcal does not currently support equivalence classes.
[^abc...]
matches any character except abc... (negated resp. complemented character list).
r1|r2
matches either r1 or r2 (alternation).
r1r2
matches r1, and then r2 (concatenation).
r+
matches one or more r's.
r*
matches zero or more r's.
r?
matches zero or one r's.
(r)
matches r (grouping).
r{n}
r{n,}
r{n,m}
matches at least n, n to any number, or n to m occurrences of r (interval expressions).
\b
matches the empty string at either the beginning or the end of a word.
\B
matches the empty string within a word.
\<
matches the empty string at the beginning of a word.
\>
matches the empty string at the end of a word.
\w
matches any word-constituent character (alphanumeric characters and the underscore).
\W
matches any character that is not word-constituent.
\`
matches the empty string at the beginning of a buffer81.
\'
matches the empty string at the end of a buffer.


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Appendix G %?... Special Texts

The %?... special texts which can be used in the text part of a Gcal resource file line can coarsely be separated into three categories. So there are special texts used for suppression output of fixed dates in definite cases. Others are replaced by particular texts or cause the shell to start external commands. See %?... Special Texts, for a general description of the special texts which may be used in the text part of a Gcal resource file line.

Some of these special texts may have an optional format instruction (called format in the further context), which affects the representation of an expanded special text. See Format Instruction, for the detailed description of the format instruction and its components. A possibly specified format within special texts which may not have a format instruction is ignored by Gcal and not displayed in output.

But Gcal is also able to represent such special texts in a special way by using a format instruction, and that by using an indirect method. For displaying, you simply assign the special text exclusively to a text variable which contains a format instruction. Nevertheless, it is important to note that the field width component of the format instruction is chosen in the way that it refers to the assigned contents of the text variable, if the format instruction has a fixed format component. The contents assigned to the text variable is only the special text, and not its expanded result. Gcal has to proceed like that, because the special text which is hidden in the text variable could not be used (here: displayed) only for a definite date, but possibly also for several dates, and that adjusted to each date it is referenced. Thus exists a special text in the text variable which has a definite length, and a format instruction also exists, whose field width component has to affect the expanded result of the special text. Indeed, Gcal does not know at the moment when the assignment of the special text to the text variable is made, of which length the expanded result will be, because this expansion is made at a much later phase in the program execution. So, in such a case, the field width component of a format instruction should have the length of the special text minimum, otherwise it is crippled and expanded respectively displayed incorrectly by the internal methods which effect the expansion.

Of course, not all possibilities concerning the representation —which are offered by the format instruction— are listed here for those special texts those expanded representation may be affected by an optional format instruction, but only some few exemplary.

And some of these special texts may also have an optional simple or special date argument (called date in the further context) or another argument (called argument in the further context). The date argument must be given in one of the following date formats in case a special text is directly trailed by it:

Special texts that may have a date argument must always be trailed by a whitespace character which is removed in output, no matter whether date was given or not!

See Summary of all %?... Special Texts, for a short-list of all applicable special texts.


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G.1 %?... special texts for date exclusion

%?... special texts used for exclusion of points of time or periods of dates are very useful if they are used together with ranges of days (see Ranges of days). The complete special text is always suppressed in output in case the fixed date text must be displayed.


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G.1.1 Exclusions with date argument %?[date] special texts

First of all, an inclusive date period %?[date] special text can be specified with the effect, that only those fixed dates are respected and displayed which are part of this period. And the specification of an exclusive date period %?[date] special text has the effect, that only those fixed dates are respected and displayed which are not part of this period.

Cleverly combined, these special texts offer very effective filtration capabilities used for the definition of special periods in a highly flexible manner, for example:

     0*d1#999 Every day of year: from January...August except April\
              %i00001#00008 %e00004#00004
     ;
     0*d1#999 Every day of year: from 1991...1993 and from 1996\
              except February 1992 and all September\
              %i1991#1993 %i1996# %e19922#19922 %e00009#00009


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G.1.1.1 Inclusive date period %i[date][#[date]] special text

%i[date][#[date]] references an inclusive date period, i.e. all dates which are part of the specified period are valid and are displayed. Of course this means, that all fixed dates which are not part of this period (not covered by it) are invalid and remain undisplayed therefore.

The first specified date defines the starting date of the fixed date, i.e. the first date the fixed date may occur. For the starting date, the following rules concerning definite omission values are valid, elucidated by using the yyyy[mm[dd|wwwn]] date format:

The second specified date defines the ending date of the fixed date, i.e. the last date the fixed date may occur. For the ending date, the following rules concerning definite omission values are valid, likewise elucidated by using the yyyy[mm[dd|wwwn]] date format:

The preceding rules are analogously valid for the other permitted date formats.

If the starting date, which is encoded in the %i... special text, is later the ending date, the %i... special text will be ignored.

In case neither the starting date nor the ending date is specified, means only ‘%i’ is given, the implicit period 1st January 1...31st December 9999 (00010101...99991231) will be used.

If only the starting date is specified, means either ‘%idate or ‘%idate# is given, the implicit ending date 31st December 9999 (99991231) will be used.

In case only the ending date is specified, means ‘%i#date is given, the implicit starting date 1st January 1 (00010101) will be used.

For example:

     0d*1#999 Every day of year: only April and July\
              %i00004#00004 %i00007#00007
     ;
     0*d1#999 Every day of year: from January...October\
              %i#000010
     ;
     0*d1#999 Every day of year: from August 1990\
              %i19908
     ;
     0*d1#999 Every day of year: from August...December\
              %i00008
     ;
     0*d1#999 Every day of year: only today%i0@t#0@t


Previous: Inclusive date period, Up: Exclusions with date argument
G.1.1.2 Exclusive date period %e[date][#[date]] special text

%e[date][#[date]] references an exclusive date period, i.e. all dates which are part of the specified period are invalid and remain undisplayed therefore. Of course this means, that all fixed dates which are not part of this period (not covered by it) are valid and are displayed.

The first specified date defines the starting date of the fixed date, i.e. the first date the fixed date may occur. For the starting date, the following rules concerning definite omission values are valid, elucidated by using the yyyy[mm[dd|wwwn]] date format:

The second specified date defines the ending date of the fixed date, i.e. the last date the fixed date may occur. For the ending date, the following rules concerning definite omission values are valid, likewise elucidated by using the yyyy[mm[dd|wwwn]] date format:

The preceding rules are analogously valid for the other permitted date formats.

If the starting date, which is encoded in the %e... special text, is later the ending date, the %e... special text will be ignored.

In case neither the starting date nor the ending date is specified, means only ‘%e’ is given, the implicit period 1st January 1...31st December 9999 (00010101...99991231) will be used.

If only the starting date is specified, means either ‘%edate’ or ‘%edate#’ is given, the implicit ending date 31st December 9999 (99991231) will be used.

In case only the ending date is specified, means ‘%e#date’ is given, the implicit starting date 1st January 1 (00010101) will be used.

For example:

     0d*1#999 Every day of year: except April and July\
             %e00004#00004 %e00007#00007
     ;
     0*d1#999 Every day of year: except January...October\
              %e#000010
     ;
     0*d1#999 Every day of year: until July 1990\
              %e19908
     ;
     0*d1#999 Every day of year: except August...December\
              %e00008
     ;
     0*d1#999 Every day of year: except today%e0@t#0@t


Previous: Exclusions with date argument, Up: Exclusions

G.1.2 Exclusions without any argument %? special texts

First of all, an inclusive day period %? special text can be specified with the effect, that only those fixed dates are respected and displayed which are part of this period. And the specification of an exclusive day period %? special text has the effect, that only those fixed dates are respected and displayed which are not part of this period.

Cleverly combined, these special texts also offer very effective filtration capabilities used for the definition of very special periods.

For example:

     0*d1#999 Every day of year: all Mondays...Fridays\
              except Wednesdays and all legal holidays\
              %r%F%V
     ;
     00001001#9999 Every day in last quarter of year: all holidays\
                   which are not on a Sunday%x %P


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G.1.2.1 Inclusive day period %? special texts

The following inclusive day periods %? special texts are respected, at which inclusive is meant for the period which is not excluded.

%v
Excludes fixed date in case it is not listed as legal holiday in the eternal holiday list.
%x
Excludes fixed date in case it is neither listed as legal holiday nor memorial day in the eternal holiday list.
%a
Excludes fixed date in case it is no Monday.
%c
Excludes fixed date in case it is no Tuesday.
%f
Excludes fixed date in case it is no Wednesday.
%g
Excludes fixed date in case it is no Thursday.
%h
Excludes fixed date in case it is no Friday.
%l
Excludes fixed date in case it is no Saturday.
%p
Excludes fixed date in case it is no Sunday.
%q
Excludes fixed date in case it is no Monday...Thursday.
%r
Excludes fixed date in case it is no Monday...Friday.


Previous: Inclusive day period, Up: Exclusions without any argument
G.1.2.2 Exclusive day period %? special texts

The following exclusive day periods %? special texts are respected, at which exclusive is meant for the period which is excluded.

%V
Excludes fixed date in case it is listed as legal holiday in the eternal holiday list.
%X
Excludes fixed date in case it is either listed as legal holiday or memorial day in the eternal holiday list.
%A
Excludes fixed date in case it is a Monday.
%C
Excludes fixed date in case it is a Tuesday.
%F
Excludes fixed date in case it is a Wednesday.
%G
Excludes fixed date in case it is a Thursday.
%H
Excludes fixed date in case it is a Friday.
%L
Excludes fixed date in case it is a Saturday.
%P
Excludes fixed date in case it is a Sunday.
%Q
Excludes fixed date in case it is a Monday...Thursday.
%R
Excludes fixed date in case it is a Monday...Friday.


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G.2 %?... special texts for text replacement

%?... special texts which are replaced by particular texts at program run-time causes the interspersing of data into the fixed date text, which quality is essentially depending on the command line arguments given for running the program. The complete special text is always replaced accordingly in output if the fixed date text must be displayed.

Cleverly combined, these special texts also offer very effective mechanisms used for the definition of particular texts in a highly flexible manner, for example:

     0*d1#999 Every day of year: Today is %K, the %n (%N)


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G.2.1 Replacements with date argument %?[date] special texts

Apart from different representations of a weekday name, it is possible to create its weekday number. Likewise, the current day-of-year number, the day number, the week number, the month name, the month number, the year number, the Moon phase, the biorhythm, and some useful difference values can be produced.

For the date argument these %?[date] special text may have, the following rules concerning definite omission values are valid, elucidated by using the yyyy[mm[dd|wwwn]] date format82:


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G.2.1.1 Weekday name %[format]K[date] special text

%K[date]
Is replaced by the complete weekday name of the current day, e.g.:
The text ‘Today is %K , the %n will be expanded to
==> ‘Today is Monday, the 10-Jun-1996, in case the actual system date is the 10th June 1996.

%>3#K[date]
Is replaced by the 3-letter weekday name of the current day, e.g.:
The text ‘Today is %>3#K0@t+1 , the %n+1 will be expanded to
==> ‘Today is Tue, the 11-Jun-1996, in case the actual system date is the 10th June 1996.

%>2#K[date]
Is replaced by the 2-letter weekday name of the current day, e.g.:
The text ‘Today is %>2#K , the %n will be expanded to
==> ‘Today is Mo, the 10-Jun-1996, in case the actual system date is the 10th June 1996.


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G.2.1.2 Weekday number %[format]?[date] special texts

The following weekday number %[format]?[date] special texts are respected, e.g.:

%W[date]
Is replaced by the weekday number of the current day, and which is determined by the Monday==1...Sunday==7 counting method, e.g.:
The text ‘Today is weekday %W , the %n will be expanded to
==> ‘Today is weekday 1, the 10-Jun-1996, in case the actual system date is the 10th June 1996.

%>1&*W[date]
Is replaced by the weekday number with trailing Ordinal Number suffix of the current day, and which is determined by the Monday==1...Sunday==7 counting method, e.g.:
The text ‘Today is weekday %>1&*W0@t+1 , the %n+1 will be expanded to
==> ‘Today is weekday 2nd, the 11-Jun-1996, in case the actual system date is the 10th June 1996.

%E[date]
Is replaced by the weekday number of the current day, and which is determined by the Monday==0...Sunday==6 counting method, e.g.:
The text ‘Today is weekday %E , the %n will be expanded to
==> ‘Today is weekday 0, the 10-Jun-1996, in case the actual system date is the 10th June 1996.

%>1&*E[date]
Is replaced by the weekday number with trailing Ordinal Number suffix of the current day, and which is determined by the Monday==0...Sunday==6 counting method, e.g.:
The text ‘Today is weekday %>1&*E , the %n will be expanded to
==> ‘Today is weekday 0th, the 10-Jun-1996, in case the actual system date is the 10th June 1996.

%I[date]
Is replaced by the weekday number of the current day, and which is determined by the Sunday==1...Saturday==7 counting method, e.g.:
The text ‘Today is weekday %I , the %n will be expanded to
==> ‘Today is weekday 2, the 10-Jun-1996, in case the actual system date is the 10th June 1996.

%>1&*I[date]
Is replaced by the weekday number with trailing Ordinal Number suffix of the current day, and which is determined by the Sunday==1...Saturday==7 counting method, e.g.:
The text ‘Today is weekday %>1&*I , the %n will be expanded to
==> ‘Today is weekday 2nd, the 10-Jun-1996, in case the actual system date is the 10th June 1996.

%J[date]
Is replaced by the weekday number of the current day, and which is determined by the Sunday==0...Saturday==6 counting method, e.g.:
The text ‘Today is weekday %J , the %n will be expanded to
==> ‘Today is weekday 1, the 10-Jun-1996, in case the actual system date is the 10th June 1996.

%>1&*J[date]
Is replaced by the weekday number with trailing Ordinal Number suffix of the current day, and which is determined by the Sunday==0...Saturday==6 counting method, e.g.:
The text ‘Today is weekday %>1&*J , the %n will be expanded to
==> ‘Today is weekday 1st, the 10-Jun-1996, in case the actual system date is the 10th June 1996.

%S[date]
Is replaced by the weekday number of the current day, and which is determined by the starting day of week==1...ending day of week==7 counting method (see Calendar option --starting-day=argument), e.g.:
The text ‘Today is weekday %S , the %n will be expanded to
==> ‘Today is weekday 4, the 10-Jun-1996, in case the actual system date is the 10th June 1996 and Friday (==5) is the starting day of week.

%>1&*S[date]
Is replaced by the weekday number with trailing Ordinal Number suffix of the current day, and which is determined by the starting day of week==1...ending day of week==7 counting method (see Calendar option --starting-day=argument), e.g.:
The text ‘Today is weekday %>1&*S , the %n will be expanded to
==> ‘Today is weekday 4th, the 10-Jun-1996, in case the actual system date is the 10th June 1996 and Friday (==5) is the starting day of week.

%T[date]
Is replaced by the weekday number of the current day, and which is determined by the starting day of week==0...ending day of week==6 counting method (see Calendar option --starting-day=argument), e.g.:
The text ‘Today is weekday %T , the %n will be expanded to
==> ‘Today is weekday 3, the 10-Jun-1996, in case the actual system date is the 10th June 1996 and Friday (==5) is the starting day of week.

%>1&*T[date]
Is replaced by the weekday number with trailing Ordinal Number suffix of the current day, and which is determined by the starting day of week==0...ending day of week==6 counting method (see Calendar option --starting-day=argument), e.g.:
The text ‘Today is weekday %>1&*T , the %n will be expanded to
==> ‘Today is weekday 3rd, the 10-Jun-1996, in case the actual system date is the 10th June 1996 and Friday (==5) is the starting day of week.


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G.2.1.3 Day-of-year number %[format]N[date] special text

%N[date]
Is replaced by the day-of-year number of the current day of year, e.g.:
The text ‘Day %N  of year, the %n will be expanded to
==> ‘Day 53 of year, the 22-Feb-1996, in case the actual system date is the 22nd February 1996.

%>03*N[date]
Is replaced by the 3-digit day-of-year number with leading zeroes of the current day of year, e.g.:
The text ‘Day %>03*N0@t-1  of year, the %n-1 will be expanded to
==> ‘Day 052 of year, the 21-Feb-1996, in case the actual system date is the 22nd February 1996.

%>1&*N[date]
Is replaced by the day-of-year number with trailing Ordinal Number suffix of the current day of year, e.g.:
The text ‘Day %>1&*N  of year, the %n will be expanded to
==> ‘Day 53rd of year, the 22-Feb-1996, in case the actual system date is the 22nd February 1996.

%>03&*N[date]
Is replaced by the 3-digit day-of-year number with leading zeroes and trailing Ordinal Number suffix of the current day of year, e.g.:
The text ‘Day %>03&*N  of year, the %n will be expanded to
==> ‘Day 053rd of year, the 22-Feb-1996, in case the actual system date is the 22nd February 1996.


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G.2.1.4 Day number %[format]D[date] special text

%D[date]
Is replaced by the day number of the current day of month, e.g.:
The text ‘Day %D , %n will be expanded to
==> ‘Day 2, 02-Feb-1996, in case the actual system date is the 2nd February 1996.

%>02*D[date]
Is replaced by the 2-digit day number with leading zero of the current day of month, e.g.:
The text ‘Day %>02*D0@t-1 , %n-1 will be expanded to
==> ‘Day 01, 01-Feb-1996, in case the actual system date is the 2nd February 1996.

%>1&*D[date]
Is replaced by the day number with trailing Ordinal Number suffix of the current day of month, e.g.:
The text ‘Day %>1&*D , %n will be expanded to
==> ‘Day 2nd, 02-Feb-1996, in case the actual system date is the 2nd February 1996.

%>02&*D[date]
Is replaced by the 2-digit day number with leading zero and trailing Ordinal Number suffix of the current day of month, e.g.:
The text ‘Day %>02&*D , %n will be expanded to
==> ‘Day 02nd, 02-Feb-1996, in case the actual system date is the 2nd February 1996.


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G.2.1.5 Week number %k[date] special text

%k[date]
Is replaced by either the 2-digit ISO week number or the standard week number with leading zero, or a 4-alphanumeric character text of the current week of year
(see Calendar option --starting-day=argument, Calendar option --iso-week-number=yes|no, and Aspects in Internationalization, for further details), e.g.:
The text ‘Today is %K  of week %k will be expanded to
==> ‘Today is Monday of week 24, in case the actual system date is the 10th June 1996.


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G.2.1.6 Month name %[format]U[date] special text

%U[date]
Is replaced by the complete month name of the current month of year, e.g.:
The text ‘Today is %U , %n will be expanded to
==> ‘Today is June, 10-Jun-1996, in case the actual system date is the 10th June 1996.

%>3#U[date]
Is replaced by the 3-letter month name of the current month of year, e.g.:
The text ‘Today is %>3#U19961010 , %n will be expanded to
==> ‘Today is Oct, 10-Jun-1996, in case the actual system date is the 10th June 1996.


Next: , Previous: Month name, Up: Replacements with date argument
G.2.1.7 Month number %[format]M[date] special text

%M[date]
Is replaced by the month number of the current month of year, e.g.:
The text ‘Month %M , %n will be expanded to
==> ‘Month 2, 22-Feb-1996, in case the actual system date is the 22nd February 1996.

%>02*M[date]
Is replaced by the 2-digit month number with leading zero of the current month of year, e.g.:
The text ‘Month %>02*M000001 , %n will be expanded to
==> ‘Month 01, 22-Feb-1996, in case the actual system date is the 22nd February 1996.

%>1&*M[date]
Is replaced by the month number with trailing Ordinal Number suffix of the current month of year, e.g.:
The text ‘Month %>1&*M , %n will be expanded to
==> ‘Month 2nd, 22-Feb-1996, in case the actual system date is the 22nd February 1996.

%>02&*M[date]
Is replaced by the 2-digit month number with leading zero and trailing Ordinal Number suffix of the current month of year, e.g.:
The text ‘Month %>02&*M , %n will be expanded to
==> ‘Month 02nd, 22-Feb-1996, in case the actual system date is the 22nd February 1996.


Next: , Previous: Month number, Up: Replacements with date argument
G.2.1.8 Year number %[format]Y[date] special text

%Y[date]
Is replaced by the year number of the current year, e.g.:
The text ‘Year %Y , %n will be expanded to
==> ‘Year 933, 22-Feb-0933, in case the actual system date is the 22nd February 933.

%>04*Y[date]
Is replaced by the 4-digit complete year number with leading zeroes of the current year, e.g.:
The text ‘Year %>04*Y0015 , %n will be expanded to
==> ‘Year 0015, 22-Feb-0933, in case the actual system date is the 22nd February 933.


Next: , Previous: Year number, Up: Replacements with date argument
G.2.1.9 Moon phase %[format]?[date] special texts

Gcal uses a very simple algorithm for detecting the Moon phase, which computes approximate values only. The Moon phase is always calculated for 0 o'clock Universal time (UTC/GMT). See Calendar option --time-offset=argument, how to change the base time for which the astronomical functions are calculated. The following Moon phase %[format]?[date] special texts are respected:

%O[date]
Is replaced by the Moon phase text of the current day of year, e.g.:
The text ‘Moon phase %O , %n will be expanded to
==> ‘Moon phase 94%+, 22-Dec-1996, in case the actual system date is the 22nd December 1996.

The constructed Moon phase text consists of a percent value, which informs about the illuminated fraction of the Moon's disk, and a trailing sign that tells something about the state of the Moon. A trailing ‘+’ sign indicates a waxing Moon, a ‘-’ sign a waning Moon, a ‘@’ sign indicates the Full Moon phase, and a ‘!’ sign the New Moon phase.

%>03*O[date]
Is replaced by the 3-digit Moon phase text with leading zeroes of the current day of year, e.g.:
The text ‘Moon phase %>03*O0@t+1 , %n+1 will be expanded to
==> ‘Moon phase 098%+, 23-Dec-1996, in case the actual system date is the 22nd December 1996.

The constructed Moon phase text consists of a percent value, which informs about the illuminated fraction of the Moon's disk, and a trailing sign that tells something about the state of the Moon. A trailing ‘+’ sign indicates a waxing Moon, a ‘-’ sign a waning Moon, a ‘@’ sign indicates the Full Moon phase, and a ‘!’ sign the New Moon phase.

%Z[date]
Is replaced by the Moon phase text graphics of the current day of year, e.g.:
The text ‘Date %n %Z  --- Moon phase %>03*O ~Text will be expanded to
==> ‘Date 08-Mar-1995 
==> ‘           (       @@@@@@
==> ‘      (              @@@@@@@@@
==> ‘    (                @@@@@@@@@@@
==> ‘  (                   @@@@@@@@@@@@
==> ‘ (                    @@@@@@@@@@@@@
==> ‘(                      @@@@@@@@@@@@@
==> ‘(                      @@@@@@@@@@@@@
==> ‘ (                    @@@@@@@@@@@@@
==> ‘  (                   @@@@@@@@@@@@
==> ‘   (                  @@@@@@@@@@@
==> ‘      (             @@@@@@@@@
==> ‘           (        @@@@@@@ --- Moon phase 041%+
==> ‘Text, in case the actual system date is the 8th March 1995.

See Fixed date option --moonimage-lines=number, how to change the size of a Moon phase text graphics.

A possibly specified format within this special text is ignored by Gcal.


Next: , Previous: Moon phase, Up: Replacements with date argument
G.2.1.10 Biorhythm %?[date] special texts

Gcal is able to create a biorhythm for any specified date of birth. The created text shows the three standard biorhythm cycles, and that are the 28 day emotional cycle, the 33 day intellectual cycle, and the 23 day physical cycle. The emotional cycle governs sensibility, nerves, moodiness, and creative ability. The intellectual cycle reflects intelligence, memory, mental alertness, and reasoning power. The physical cycle represents physical strength, endurance, energy and resistance. All cycles start in the zero point at the date of birth and swing like sine curves between their positive and negative maximum values. The periods above the zero point show the days of full vitality and efficiency while the periods below the zero point indicate days of reduced efficiency. The biorhythm is implemented for entertaining purposes only! It is up to the user to interpret the biorhythm texts.

Gcal counts critical days, positive likewise negative days. Critical days are those days in which one or more of the biological cycles crosses the zero point. At that time, one's system is said to be in a state of flux and it may be desirable to exhibit caution. Positive days are those days in which one or more of the biological cycles have a positive maximum value. At that time, one's system is said to be in a raised state. Negative days are those days in which one or more of the biological cycles have a negative maximum value. At that time, one's system is said to be in a lessen state.

The following biorhythm %?[date] special texts are respected:

%,[date]
Is replaced by the biorhythm text of the current day of year, e.g.:
The text ‘%,19620921 will be expanded to
==> ‘1! 0+ 0- , Emo=+022%- Int=-091%+ Phy=-014%-, in case the actual system date is the 12th December 1996.

The preceding example shows the calculated biorhythm expressed as a series of values for a person born in 1962, September 21st. The constructed text consists of two parts, and that is on the one hand a triplet of total values which indicate the critical, positive and negative day. And on the other hand a triplet of values which indicate the emotional, intellectual and physical cycle.

In the first triplet of total values, a ‘!’ suffix means a critical day, a ‘+’ indicates a positive day, and a ‘-’ suffix marks a negative day.

In the second triplet of values, each single cycle percent value consists of a leading positive or negative sign that tells something about the distance of this value to the zero point, and a trailing character that tells something about the state of each cycle. A trailing ‘+’ character marks a waxing phase, a ‘-’ suffix means a waning phase, and a ‘@’ indicates the maximum value of a phase.

%;[date]
Is replaced by the biorhythm text graphics of the current day of year, e.g.:
The text ‘%;19620921 will be expanded to
==> ‘0-  I               P 1   E                +0, in case the actual system date is the 12th December 1996.

The preceding example shows the calculated biorhythm expressed as a text graphics line for a person born in 1962, September 21st. The constructed line is a bar with a negative and positive axis of adjustable length (see Fixed date option --biorhythm-axis=number), which left margin is represented by the total value of the negative days (the ‘0-’ in this case), and which right margin is represented by the total value of the positive days (the ‘+0’ in this case). The zero point of the co-ordinate is represented by the total value of the critical days, which is the ‘1’ in this case. The emotional, intellectual and the physical phase value is accordingly placed in scaled manner on this bar, and that by using the initial letter of the cycle in each case (‘E’, ‘I’ and ‘P’). Coincidental phase values are marked by a ‘@’ character.


Previous: Biorhythm, Up: Replacements with date argument
G.2.1.11 Difference value %[format]?[date] special texts

The following difference value %[format]?[date] special texts are respected:

%ydate
Is replaced by a year difference value, e.g.:
The text ‘Sylvester 1912 is %y1912  years ago will be expanded to
==> ‘Sylvester 1912 is -82 years ago, in case the year of the actual system date is 1994.

%B[date]
Is replaced by an age value, e.g.:
The text ‘My %B1962  birthday%i1952#2062 will be expanded to
==> ‘My 32 birthday, in case the year of the actual system date is 1994.

Those age values are only displayed, if the computation of an age value is greater zero. The fixed date warning in preceding example is displayed only in case the current year is greater than 1952 and less than 2062.

%>1&*B[date]
Is replaced by an age value with trailing Ordinal Number suffix, e.g.:
The text ‘My %>1&*B1962  birthday%i1952#2062 will be expanded to
==> ‘My 32nd birthday, in case the year of the actual system date is 1994.

Those age values are only displayed, if the computation of an age value is greater zero. The fixed date warning in preceding example is displayed only in case the current year is greater than 1952 and less than 2062.


Next: , Previous: Replacements with date argument, Up: Replacements

G.2.2 Replacements with other argument %[format]?[argument] special texts

Apart from different representations of the actual system time, a fixed format date text can be created. Moreover, it is possible to produce a day number, which bears the Julian date as base date and which can be deferred if needed. Furthermore, the approximate distance and the course angle between two geographic point locations, and different Sun and Moon oriented data and times for at pleasure any geographical location can be created. It is also possible to display the contents of environment variables in the fixed date text.

For the argument these %?[argument] special texts may have, no special rules concerning definite omission values are valid.


Next: , Previous: Replacements with other argument, Up: Replacements with other argument
G.2.2.1 Actual clocktime %[format]?[argument] special texts

Gcal is able to represent the actual clocktime as local/zone time and as Universal time (UTC/GMT), and additionally the RFC-82283 style numerical Universal time timezone offset value and the actual numerical local time timezone offset value. See Actual local time %t[argument] special text, for the detailed description of all components of the argument, which may trail the actual clocktime %[format]?[argument] special texts. All actual clocktime %[format]?[argument] special texts must always be trailed by a whitespace character which is removed in output! The following actual clocktime %[format]?[argument] special texts are respected:

%t[argument]
%t[*][[+|-]mmmm|hh:[mm]] references the actual local time, which is displayed by using the hh:mm output format, e.g.:
The text ‘Local time: %t  --> Dentist at 10:00 will be expanded to
==> ‘Local time: 07:32 --> Dentist at 10:00, in case the actual local time value is 07:32 o'clock (hh:mm).

If only %t is specified, the local time value will implicitly be displayed by using the 24-hours format. For displaying using the 12-hours format, add a ‘*’ character directly behind %t, e.g. ‘%t*’.

A displacement value may trail the %t special text, which has to be specified either by using the [+|-]mmmm format or the [+|-]hh:[mm] format. [+|-]mmmm adds respectively subtracts the specified amount of minutes mmmm from the local time value (range 0...9999), while [+|-]hh:[mm] adds respectively subtracts the given amount of hours hh (range 0...99) and minutes mm (range 0...59) from the local time value. The displacement value is always added to the local time value in case it is specified without a +|- sign. In case Gcal is unable to compute the actual local time in hh:mm format by reason of a misspecified argument, a ??:?? text will be created instead of the actual local time in hh:mm format.

The text ‘Local time: %t-3:  --> Dentist at 10:00 will be expanded to
==> ‘Local time: 04:32 --> Dentist at 10:00, in case the actual local time value is 07:32 o'clock (hh:mm).

%[format]'[argument]
%[format]'[[+|-]mmmm|hh:[mm]] references the actual local time in minutes since midnight, which is displayed by using the m[m...] output format, e.g.:
The text ‘Local time: %'  --> Dentist at 10:00 will be expanded to
==> ‘Local time: 452 --> Dentist at 10:00, in case the actual local time value is 07:32 o'clock (hh:mm).

In case Gcal is unable to compute the actual local time in m[m...] format by reason of a misspecified argument, a ?? text will be created instead of the actual local time in m[m...] format.

%[format]_[argument]
%[format]_[*][[+|-]mmmm|hh:[mm]] references the actual local time hour, which is displayed by using the h[h...] output format, e.g.:
The text ‘Local time hour: %_-1: will be expanded to
==> ‘Local time hour: 6 in case the actual local time value is 07:32 o'clock (hh:mm).

In case Gcal is unable to compute the actual local time hour by reason of a misspecified argument, a ?? text will be created instead of the actual local time hour h[h...].

%[format]?[argument]
%[format]?[[+|-]mmmm|hh:[mm]] references the actual local time minute, which is displayed by using the m[m...] output format, e.g.:
The text ‘Local time minute: %>04*?+:2 will be expanded to
==> ‘Local time minute: 0034 in case the actual local time value is 07:32 o'clock (hh:mm).

In case Gcal is unable to compute the actual local time minute by reason of a misspecified argument, a ?? text will be created instead of the actual local time minute m[m...].

%[format]{[argument]
%[format]{[[+|-]mmmm|hh:[mm]] references the actual local time 12-hour format suffix, which is displayed as am|pm, e.g.:
The text ‘Local time suffix: %{ will be expanded to
==> ‘Local time suffix: am in case the actual local time value is 07:32 o'clock (hh:mm).

In case Gcal is unable to compute the actual local time 12-hour format suffix by reason of a misspecified argument, a ?? text will be created instead of the actual local time 12-hour format suffix am|pm.

%@[argument]
%@[*][[+|-]mmmm|hh:[mm]] references the actual Universal time (UTC/GMT), which is displayed by using the hh:mm/date output format, e.g.:
The text ‘Universal time: %@*-3. will be expanded to
==> ‘Universal time: 03:32am/15-Feb-1999, in case the actual date is the 15th February 1999 and the actual Universal time value is 06:32 o'clock (hh:mm).

In case Gcal is unable to compute the actual Universal time in hh:mm/date format by reason of a misspecified argument, a ??:??/??-???-???? text will be created instead of the actual Universal time in hh:mm/date format.

%[format]`[argument]
%[format]`[[+|-]mmmm|hh:[mm]] references the actual Universal time in minutes since midnight, which is displayed by using the m[m...]/date output format, e.g.:
The text ‘Universal time: %>06*`-3: will be expanded to
==> ‘Universal time: 000212/15-Feb-1999 in case the actual date is the 15th February 1999 and the actual Universal time value is 06:32 o'clock (hh:mm).

In case Gcal is unable to compute the actual Universal time in m[m...]/date format by reason of a misspecified argument, a ??/??-???-???? text will be created instead of the actual Universal time in m[m...]/date format.

%[format].[argument]
%[format].[*][[+|-]mmmm|hh:[mm]] references the actual Universal time hour, which is displayed by using the h[h...] output format, e.g.:
The text ‘Universal time hour: %.-1: will be expanded to
==> ‘Universal time hour: 5 in case the actual Universal time value is 06:32 o'clock (hh:mm).

In case Gcal is unable to compute the actual Universal time hour by reason of a misspecified argument, a ?? text will be created instead of the actual Universal time hour h[h...].

%[format]/[argument]
%[format]/[[+|-]mmmm|hh:[mm]] references the actual Universal time minute, which is displayed by using the m[m...] output format, e.g.:
The text ‘Universal time minute: %>04*/+:2 will be expanded to
==> ‘Universal time minute: 0034 in case the actual Universal time value is 06:32 o'clock (hh:mm).

In case Gcal is unable to compute the actual Universal time minute by reason of a misspecified argument, a ?? text will be created instead of the actual Universal time minute m[m...].

%[format]}[argument]
%[format]}[[+|-]mmmm|hh:[mm]] references the actual Universal time 12-hour format suffix, which is displayed as am|pm, e.g.:
The text ‘Universal time suffix: %>1w*}+10: will be expanded to
==> ‘Universal time suffix: Pm in case the actual Universal time value is 06:32 o'clock (hh:mm).

In case Gcal is unable to compute the actual Universal time 12-hour format suffix by reason of a misspecified argument, a ?? text will be created instead of the actual Universal time 12-hour format suffix am|pm.

%"[argument]
%"[[+|-]mmmm|hh:[mm]] references the RFC-822 style numerical Universal time timezone offset value, which is displayed by using the +|-hhmm output format, e.g.:
The text ‘Universal time timezone offset value: %"-90 will be expanded to
==> ‘Universal time timezone offset value: -0130, at which calculations are always based on the timezone of the Universal time UTC/GMT.

In case Gcal is unable to compute the numerical Universal time timezone offset value by reason of a misspecified argument, a +???? text will be created instead of the numerical Universal time timezone offset value +|-hhmm.

%=[argument]
%=[[+|-]mmmm|hh:[mm]] references the RFC-822 style actual numerical local time timezone offset value, which is displayed by using the +|-hhmm output format, e.g.:
The text ‘Local time timezone offset value CET: %=-10 will be expanded to
==> ‘Local time timezone offset value CET: +0050, in case the actual timezone is equal the Central European (winter)time CEWT/CET (+hhmm). Calculations are always based on the timezone of the local time.

In case Gcal is unable to compute the actual numerical local time timezone offset value by reason of a misspecified argument, a +???? text will be created instead of the actual numerical local time timezone offset value +|-hhmm.


Next: , Previous: Actual clocktime, Up: Replacements with other argument
G.2.2.2 Textual date %n[argument] special text

%n[[+|-]n] references the current respectively queried day number relative to the current date ‘+/-’ n days and is replaced by a date text by using the fixed ‘%>02*D-%>3#U-%>04*Y format, e.g.:

The resource file line ‘1962Sep21 10000 days old: %n+10000 will be expanded to
==> ‘10000 days old: 06-Feb-1990, in case you call Gcal with the simple -c option and the command sep 1962 (see Single command mm yyyy).


Next: , Previous: Textual date, Up: Replacements with other argument
G.2.2.3 Julian day number %[format]j[argument] special text

%[format]j[[+|-]n] references the current respectively queried Julian day number relative to the actual system date (==today). This day number is based on the date 1st January 4713 BCE —which is the starting day zero of a consecutive day counting used in astronomical computations— and is known as the Julian Date (J.D.). The real zero of this date is at 12 o'clock Universal time (UTC/GMT); the day does not change at midnight, but at noon Universal time. Here, Gcal does not evaluate the timezone returned by the systems date function. For that reason, this day number is represented without a time fraction on the supposition that the day has already changed at noon. If you do not like the feature that the day displayed has already changed at noon, you can decrease the resulting Julian day number of that special text always by one, e.g. ‘%j-1’.

For example:

The resource file line ‘0 Julian day %j since 01-Jan-4713 BCE will be expanded to
==> ‘Julian day 2437929 since 01-Jan-4713 BCE, in case you call Gcal with the -c %19620921 option and no command.

If the %[format]j text is directly trailed by an unsigned number, this number is always subtracted from the real Julian day number. So you are able to work with any quantities referenced, e.g.:

The resource file line ‘0 Julian day %j2415021 since 01-Jan-1900 will be expanded to
==> ‘Julian day 4 since 01-Jan-1900, in case you call Gcal with the -c %19000105 option and no command.


Next: , Previous: Julian day number, Up: Replacements with other argument
G.2.2.4 Geographical distance and course angle %[format]bargument special text

%[format]b[*][mode]ISO-6709:1983-co-ordinate-1/ISO-6709:1983-co-ordinate-2 references either the approximate air line distance or the approximate course angle (true track)84 between any of two geographic point locations. The selection, which value has to be calculated by using this special text is done by specifying the mode part of the preceding argument. Actually, exactly three different modes can be used that are represented by the ‘0...2 characters:

Mode Description

0 Calculates the air line distance between ISO-6709:1983-co-ordinate-1 and ISO-6709:1983-co-ordinate-2. The calculated air line distance value is displayed in kilometers by default. A ‘*’ character directly before this mode character causes Gcal to display the distance value for another quantity, and that in statute miles; where one statute mile is equal to 1.609344 kilometer. If Gcal is unable to compute the approximate distance between the two geographic point locations by reason of a misspecified argument, a ?? text will be created instead of the distance value.

1 Calculates the course angle (true track) between ISO-6709:1983-co-ordinate-1 and ISO-6709:1983-co-ordinate-2. The calculated course angle value is displayed in degrees and arcminutes by default. The course angle is measured clockwise relative to the geographic, true North (not the magnetic North as shown by a compass), where angle values for the North direction are both denoted as 0 degree and 360 degree. A ‘*’ character directly before this mode character causes Gcal to display the course angle value using another style; and that in decimal degrees. If Gcal is unable to compute the approximate course angle between the two geographic point locations by reason of a misspecified argument, a ???d??' text will be created instead of the course angle value.

2 Like mode 1, but the course angle (true track) between ISO-6709:1983-co-ordinate-2 and ISO-6709:1983-co-ordinate-1 is calculated.

If no mode is given, Gcal automatically uses that mode, which is enabled by the mode character ‘0’. If a mode character is given that is not according to one of the ‘0...2 characters, Gcal also automatically uses that mode, which is enabled by the mode character ‘0’.

After the optional style and mode characters, the latitude and longitude of the geographic co-ordinates follows, for which the calculations must be made. They must be conform the ISO-6709:1983 standard representation of latitude and longitude for geographic point locations. The two co-ordinates have to be separated by a ‘/’ termination character from each other.

See Arguments of the Sun oriented special texts, for the detailed description of the components of the ISO-6709:1983 standard representation of latitude and longitude for geographic point locations.

For example:

The text ‘Distance Paris-Tokyo: %b+4852+00220/+3542+13946 km will be expanded to
==> ‘Distance Paris-Tokyo: 9746km.
The text ‘Distance Paris-Tokyo: %b*0+4852+00220/+3542+13946 ms will be expanded to
==> ‘Distance Paris-Tokyo: 6056ms.
The text ‘Course angle Paris-Tokyo: %b1+4852+00220/+3542+13946 will be expanded to
==> ‘Course angle Paris-Tokyo: 033d22'.
The text ‘Course angle Tokyo-Paris: %b*2+4852+00220/+3542+13946 will be expanded to
==> ‘Course angle Tokyo-Paris: 333.548.

While praying, people of Islamic faith always turn their heads into the direction of Makkah, Saudi-Arabia. Now by means of Gcal, these people can easily find out for their respective location, where they have to turn to, and that by:

     %b1ISO-6709:1983-co-ordinate-1/+212516+0394929

where ISO-6709:1983-co-ordinate-1 is simply replaced by the co-ordinate of the respective location.

See Fixed date option --precise, how to obtain a more precise representation of the values that are caused by this special text.

This special text must always be trailed by a whitespace character which is removed in output!


Next: , Previous: Geographical distance and course angle, Up: Replacements with other argument
G.2.2.5 Sun data %[format]?argument special texts

%[format]o[*][mode]ISO-6709:1983-co-ordinate[,[+|-]mmmm|hh:[mm]] references the approximate time of sunrise by default,
%[format]s[*][mode]ISO-6709:1983-co-ordinate[,[+|-]mmmm|hh:[mm]] references the approximate time of sunset by default,
%[format]u[*][mode]ISO-6709:1983-co-ordinate[,[+|-]mmmm|hh:[mm]] references the approximate period of visibility of the Sun (solar day length) by default,
%[format]z[*][mode]ISO-6709:1983-co-ordinate[,[+|-]mmmm|hh:[mm]] references the approximate period of non-visibility of the Sun (solar night length) by default.

All these special texts can be used for at pleasure any geographic point location, i.e. it is possible to determine different astronomical values for any location on the globe, and that for at pleasure any clocktime with a resolution of a single minute within the period of the years AD 1 until AD 9999, that is respected by Gcal.

The selection which value has to be calculated by these special texts is done by specifying the mode part of the preceding argument. Actually, exactly 54 different modes can be used that are represented by the ‘0...9, ‘a...z and ‘A...R characters, and which create different kind of results that are depending on the special text used. First of all, here is a table in which all usable modes are described and explained sufficiently. You can also see from this table, which Sun oriented special text or texts are corresponding to which mode, i.e. cause the determination of an astronomical value as it is described in the table:

Mode Special text Description

0 o, s Calculates the approximate midnight time of the Sun. The astronomical midnight time of the Sun is at that clocktime, when the Sun holds an azimuth (horizontal angular distance between the vertical circle, that passes the Sun, and the North point) of either precisely 0 degrees of precisely 180 degrees (noon line), which depends on the season and the geographical location. At that clocktime, the Sun is close its lowest culmination point, i.e. close the lowest point below or above the horizontal plane the Sun transits during this day.

1 o, s Calculates the approximate noon time of the Sun. The astronomical noon time of the Sun is at that clocktime, when the Sun holds an azimuth of either precisely 180 degrees of precisely 0 degrees (noon line), which depends on the season and the geographical location. At that clocktime, the Sun is close its highest culmination point, i.e. close the highest point above or below the horizontal plane the Sun transits during this day. People of Islamic faith normally pray for the second time on the day during the period, which is between the astronomical noon time of the Sun (or some minutes later) and the Islamic prayer time by the name of Asr. These people commonly use the term Zuhr for this prayer time. The timing of Asr depends on the length of the shadow cast by a vertical pole (gnomon). According to the Shafi school of jurisprudence, Asr begins when the length of the shadow of a vertical pole exceeds the length of the pole. According to the Hanafi school of jurisprudence, Asr begins when the length of the shadow exceeds twice the length of the vertical pole. In both cases, the minimum length of the shadow at astronomical noon time of the Sun is subtracted from the length of the shadow before comparing it with the length of the pole. See Islamic Asr-1 prayer time, and Islamic Asr-2 prayer time, for further details.

2 o Calculates the approximate time when the center of the Sun passes a reference altitude of 0 degrees on a mathematical-geocentric horizon in the morning; thus rising. A mathematical horizon is a purely geometrically-built horizon which disregards the phenomenon of refraction as it arises in reality by the influence of the Earth's atmosphere. A geocentrical horizon is the horizontal plane that passes through the Earth's center, orthogonal to the observer's local vertical. In the further context, the shorter term mathematical horizon is used which actually means the mathematical-geocentric horizon.

2 s Calculates the approximate time when the center of the Sun passes a reference altitude of 0 degrees on a mathematical horizon in the evening; thus setting.

2 u Calculates the approximate period while the center of the Sun is above a reference altitude of 0 degrees on a mathematical horizon; thus is visible.

2 z Calculates the approximate period while the center of the Sun is below a reference altitude of 0 degrees on a mathematical horizon; thus is non-visible.

3 o Calculates the approximate time when the upper limb of the Sun passes a reference altitude of 0 degrees on a mathematical horizon in the morning; thus rising. The above mentioned reference altitude is computed from the value of the Sun's semidiameter as it appear at that clocktime. If the reference altitude that is referring to the Sun's upper limb is converted to a reference altitude that is referring to the Sun's center, this results in a value of about 16 arcminutes below the geocentric horizon.

3 s Calculates the approximate time when the upper limb of the Sun passes a reference altitude of 0 degrees on a mathematical horizon in the evening; thus setting. The above mentioned reference altitude is computed from the value of the Sun's semidiameter as it appear at that clocktime.

3 u Calculates the approximate period while the upper limb of the Sun is above a reference altitude of 0 degrees on a mathematical horizon; thus is visible.

3 z Calculates the approximate period while the upper limb of the Sun is below a reference altitude of 0 degrees on a mathematical horizon; thus is non-visible.

4 o Calculates the approximate time when the center of the Sun passes a reference altitude of 34 arcminutes below the geocentric horizon in the morning; thus rising. The phenomenon of refraction is already respected in this as it arises in reality by the influence of the Earth's atmosphere, and that with the standard value of 34 arcminutes, which can indirectly be changed by using the --atmosphere option. Fixed dates option --atmosphere=air-pressure[,temperature], how to change the base data of the atmosphere, so that the atmospheric conditions as defined by it are used to calculate the amount of refraction.

4 s Calculates the approximate time when the center of the Sun passes a reference altitude of 34 arcminutes below the geocentric horizon in the evening; thus setting. The phenomenon of refraction is already respected in this as it arises in reality by the influence of the Earth's atmosphere, and that with the standard value of 34 arcminutes, which can indirectly be changed by using the --atmosphere option.

4 u Calculates the approximate period while the center of the Sun is above a reference altitude of 34 arcminutes below the geocentric horizon; thus is visible.

4 z Calculates the approximate period while the center of the Sun is below a reference altitude of 34 arcminutes below the geocentric horizon; thus is non-visible.

5 o Calculates the approximate time when the upper limb of the Sun passes a reference altitude of 34 arcminutes below the geocentric horizon in the morning; thus rising. This kind of rise time calculation is done according to the standard calculation method as it is commonly used internationally. The phenomenon of refraction is already respected in this as it arises in reality by the influence of the Earth's atmosphere, and that with the standard value of 34 arcminutes, which can indirectly be changed by using the --atmosphere option. Fixed dates option --atmosphere=air-pressure[,temperature], how to change the base data of the atmosphere, so that the atmospheric conditions as defined by it are used to calculate the amount of refraction. The above mentioned reference altitude is computed from the respective values of the Sun's semidiameter and (standard) refraction as they appear at that clocktime. If the reference altitude that is referring to the Sun's upper limb is converted to a reference altitude that is referring to the Sun's center, this results in a value of about 50 arcminutes below the geocentric horizon.

5 s Calculates the approximate time when the upper limb of the Sun passes a reference altitude of 34 arcminutes below the geocentric horizon in the evening; thus setting. This kind of set time calculation is done according to the standard calculation method as it is commonly used internationally. The phenomenon of refraction is already respected in this as it arises in reality by the influence of the Earth's atmosphere, and that with the standard value of 34 arcminutes, which can indirectly be changed by using the --atmosphere option. The above mentioned reference altitude is computed from the respective values of the Sun's semidiameter and (standard) refraction as they appear at that clocktime. People of Islamic faith normally pray for the second-last time on the day at this clocktime, or some minutes later. These people commonly use the term Maghrib for this prayer time.

5 u Calculates the approximate period while the upper limb of the Sun is above a reference altitude of 34 arcminutes below the geocentric horizon; thus is visible. This kind of visibility period calculation is done according to the standard calculation method as it is commonly used internationally.

5 z Calculates the approximate period while the upper limb of the Sun is above a reference altitude of 34 arcminutes below the geocentric horizon; thus is non-visible. This kind of non-visibility period calculation is done according to the standard calculation method as it is commonly used internationally.

6 o Calculates the approximate time when the center of the Sun passes a reference altitude of 6 degrees below a mathematical horizon in the morning; thus the beginning of civil twilight. The scattered light of the Sun that is remaining at the beginning of the civil twilight phase is in general not yet sufficient for reading outside without artificial illumination.

6 s Calculates the approximate time when the center of the Sun passes a reference altitude of 6 degrees below a mathematical horizon in the evening; thus the ending of civil twilight.

6 u Calculates the approximate period while the center of the Sun is above a reference altitude of 6 degrees below a mathematical horizon; thus the period, while the center of the Sun is always above -6 degrees.

6 z Calculates the approximate period while the center of the Sun is below a reference altitude of 6 degrees below a mathematical horizon; thus the period, while the center of the Sun is always below -6 degrees.

7 o Calculates the approximate time when the center of the Sun passes a reference altitude of 12 degrees below a mathematical horizon in the morning; thus the beginning of nautical twilight. The scattered light of the Sun that is remaining at the beginning of the nautical twilight phase is in general not yet sufficient for navigation using a sea horizon.

7 s Calculates the approximate time when the center of the Sun passes a reference altitude of 12 degrees below a mathematical horizon in the evening; thus the ending of nautical twilight.

7 u Calculates the approximate period while the center of the Sun is above a reference altitude of 12 degrees below a mathematical horizon; thus the period, while the center of the Sun is always above -12 degrees.

7 z Calculates the approximate period while the center of the Sun is below a reference altitude of 12 degrees below a mathematical horizon; thus the period, while the center of the Sun is always below -12 degrees.

8 o Calculates the approximate time when the center of the Sun passes a reference altitude of 15 degrees below a mathematical horizon in the morning; thus the beginning of amateur-astronomical twilight. The scattered light of the Sun that is remaining at the beginning of the amateur-astronomical twilight phase is in general yet so faint that most astronomical observations can be made.

8 s Calculates the approximate time when the center of the Sun passes a reference altitude of 15 degrees below a mathematical horizon in the evening; thus the ending of amateur-astronomical twilight.

8 u Calculates the approximate period while the center of the Sun is above a reference altitude of 15 degrees below a mathematical horizon; thus the period, while the center of the Sun is always above -15 degrees.

8 z Calculates the approximate period while the center of the Sun is below a reference altitude of 15 degrees below a mathematical horizon; thus the period, while the center of the Sun is always below -15 degrees.

8 o Calculates the approximate time when the center of the Sun passes a reference altitude of 18 degrees below a mathematical horizon in the morning; thus the beginning of astronomical twilight. No appreciable scattered sunlight is remaining at the beginning of the astronomical twilight phase, the sky is completely dark yet. People of Islamic faith normally pray for the first time on the day during the period, which is between this clocktime and the time of standard sunrise. These people commonly use the term Fajr for this prayer time. See Standard rise time of the Sun, for further details.

9 s Calculates the approximate time when the center of the Sun passes a reference altitude of 18 degrees below a mathematical horizon in the evening; thus the ending of astronomical twilight. People of Islamic faith normally pray for the last time on the day at this clocktime, or some minutes later. These people commonly use the term Isha for this prayer time.

9 u Calculates the approximate period while the center of the Sun is above a reference altitude of 18 degrees below a mathematical horizon; thus the period, while the center of the Sun is always above -18 degrees.

9 z Calculates the approximate period while the center of the Sun is below a reference altitude of 18 degrees below a mathematical horizon; thus the period, while the center of the Sun is always below -18 degrees.

a o, s Calculates the approximate topocentric, apparent elevation of the Sun, thus the vertical angular distance between the Sun's center and the horizon, in degrees and arcminutes as it happen at civil midnight time. Results with a negative sign signify that the Sun's center is below the horizon at the moment, and results with a positive sign mean that the momentary center of the Sun is above the horizon. Observations of celestial objects that are done from the surface of the Earth yield in topocentrically based data. The locations of the celestial bodies are often at another place if the data is topocentrically determined instead of determine it geocentrically, i.e. at the fictitious center of the Earth. This is mainly caused by the refraction, which raises a celestial body to another location as it is been in reality. Because the terrestrial globe flattens towards the pole caps and therefore cannot be taken as an ideally shaped sphere, the individual Earth radius between the observer's location and the center of the Earth also affects the computation of topocentrically based data.

b o, s Calculates the approximate topocentric, apparent azimuth of the Sun in degrees and arcminutes as it happen at civil midnight time.

c o, s Calculates the approximate topocentric, apparent declination of the Sun, thus the vertical angular distance between the Sun's center and the celestial equator, in degrees and arcminutes as it happen at civil midnight time. Results with a negative sign signify that the Sun's center is below the celestial equator at the moment, and results with a positive sign mean that the momentary center of the Sun is below the celestial equator.

d o, s Calculates the approximate topocentric, apparent ecliptic longitude of the Sun, thus the horizontal angular distance between the Sun's center and the vernal equinox point on the ecliptic (the zodiacal line or Sun's orbit), in degrees and arcminutes as it happen at civil midnight time.

e o, s Calculates the approximate topocentric, apparent right ascension of the Sun, thus the horizontal angular distance between the Sun's center and the hour circle that passes through the vernal equinox point on the ecliptic, as time value in hours and minutes as it happen at civil midnight time.

f o, s Calculates the approximate topocentric, apparent distance of the Sun from the Earth in astronomical units as it happen at civil midnight time. An astronomical unit, abbreviated by ae, is equal to the mean distance of the Sun from the Earth, which is about 149,597,870.691 kilometers.

g o, s Calculates the approximate topocentric, apparent horizontal parallax of the Sun in degrees and arcminutes as it happen at civil midnight time. The horizontal parallax of the Sun specifies the diameter of the Earth as it is seen from the surface of the Sun.

h o, s Calculates the approximate topocentric, apparent semidiameter of the Sun in degrees and arcminutes as it happen at civil midnight time.

i o, s Calculates the approximate refraction of the Earth's atmosphere in degrees and arcminutes as it happen at civil midnight time.

j o, s Calculates the approximate geocentric, apparent elevation of the Sun in degrees and arcminutes as it happen at civil midnight time. Results with a negative sign signify that the Sun's center is below the horizon at the moment, and results with a positive sign mean that the momentary center of the Sun is above the horizon.

k o, s Calculates the approximate geocentric, apparent azimuth of the Sun in degrees and arcminutes as it happen at civil midnight time.

l o, s Calculates the approximate geocentric, apparent declination of the Sun in degrees and arcminutes as it happen at civil midnight time. Results with a negative sign signify that the Sun's center is below the celestial equator at the moment, and results with a positive sign mean that the momentary center of the Sun is above the celestial equator.

m o, s Calculates the approximate geocentric, apparent ecliptic longitude of the Sun in degrees and arcminutes as it happen at civil midnight time.

n o, s Calculates the approximate geocentric, apparent right ascension of the Sun as time value in hours and minutes as it happen at civil midnight time.

o o, s Calculates the approximate geocentric, apparent distance of the Sun from the Earth in astronomical units as it happen at civil midnight time.

p o, s Calculates the approximate geocentric, apparent horizontal parallax of the Sun in degrees and arcminutes as it happen at civil midnight time.

q o, s Calculates the approximate geocentric, apparent semidiameter of the Sun in degrees and arcminutes as it happen at civil midnight time.

r o, s Calculates the approximate delta-t in seconds as it happen at civil midnight time. Delta-t is the difference between the Terrestrial Dynamical time (abbreviated by TDT), that was formerly known as Ephemeris time (abbreviated by ET), and the Universal time (UT). Thus, ‘delta-t == TDT - UT.

s o, s Calculates the approximate, apparent location oriented sidereal time (local sidereal time (LAST), also known as local star time) in hours and minutes as it happen at civil midnight time. A star day is the period between two consecutive upper culminations of the vernal equinox point on the ecliptic in the meridian of the observer's location. Therefore, the local star time is the momentary period, which is past between the last upper culmination of the vernal equinox point in the meridian of the observer's location (the momentary hour angle of the vernal equinox point), thus the right ascension of the stars in the observer's meridian at the moment.

t o, s Outputs the base time as time value in hours and minutes, for which the dynamical, i.e. depending on the respective clocktime, astronomical data and times of the Sun are calculated. Without a given --time-offset=argument option, the astronomical data and times of the Sun are always calculated for 0 o'clock Universal time (UTC/GMT). See Calendar option --time-offset=argument, for further details.

u o, s Calculates the approximate Julian date in days as it happen at civil midnight time. See Julian day number, for further information about the Julian date.

v o, s Calculates the approximate Julian Ephemeris date, thus a Julian date that is corrected by delta-t, in days as it happen at civil midnight time.

w o, s Calculates the approximate difference between true solar time and mean solar time as time value in hours and minutes as it happen at civil midnight time. This so-called equation of time is a correction to be added to the true solar time —as read on a sundial— to obtain the mean solar time. A true solar day is the period between two consecutive lower culminations of the Sun. This entity is taken as the base for deriving the true solar time (as it is also shown by a sundial during the day). A star day is also known as a mean solar day. Because the Sun apparently shifts with respect to the vernal equinox point on the ecliptic due to the Earth's orbit around the Sun, the star day and the true solar day have a different length. As the true Sun namely moves irregularly through the ecliptic, a fictitious mean Sun with a symmetrical motion through the celestial equator is used for deriving the mean solar time. So, this difference in time is a consequence of the ellipticity and tilt of the Earth's orbit, causing the irregular apparent movement of the Sun across the sky.

x o, s Calculates the difference of the approximate topocentric, apparent elevation of Sun and Moon (delta), at which the Sun is used as the reference point, in degrees and arcminutes as it happen at civil midnight time. Results with a negative sign signify that the momentary center of the Sun is at an elevation that is below the momentary elevation of the Moon's center; thus the Sun is lower than the Moon. Results with a positive sign signify that the momentary center of the Sun is at an elevation that is above the momentary elevation of the Moon's center; thus the Sun is higher than the Moon.

y o, s Calculates the difference of the approximate topocentric, apparent azimuth of Sun and Moon (delta), at which the Sun is used as the reference point, in degrees and arcminutes as it happen at civil midnight time. The result specifies the horizontal angular distance, by which the momentary center of the Sun is distant from the momentary Moon's center, and that measured at the vertical circles that pass the Sun and the North point and the Moon and the North point. Results with a negative sign signify that the Moon is to the right (clockwise) of the Sun if one looks to the Sun — or alternatively expressed, that the Sun is to the left (anti-clockwise) of the Moon. Results with a positive sign signify that the Moon is to the left (anti-clockwise) of the Sun if one looks to the Sun — or alternatively expressed, that the Sun is to the right (clockwise) of the Moon.

z o, s Calculates the difference of the approximate geocentric, apparent elevation of Sun and Moon (delta), at which the Sun is used as the reference point, in degrees and arcminutes as it happen at civil midnight time.

A o, s Calculates the difference of the approximate geocentric, apparent azimuth of Sun and Moon (delta), at which the Sun is used as the reference point, in degrees and arcminutes as it happen at civil midnight time.

B o Calculates the difference of the approximate topocentric, apparent elevation of Sun and Moon (delta), at which the Sun is used as the reference point, in degrees and arcminutes as it happen at standard rise time of the Sun. See Standard rise time of the Sun, for further details.

B s Calculates the difference of the approximate topocentric, apparent elevation of Sun and Moon (delta), at which the Sun is used as the reference point, in degrees and arcminutes as it happen at standard set time of the Sun. See Standard set time of the Sun, for further details.

C o Calculates the difference of the approximate topocentric, apparent azimuth of Sun and Moon (delta), at which the Sun is used as the reference point, in degrees and arcminutes as it happen at standard rise time of the Sun. See Standard rise time of the Sun, for further details.

C s Calculates the difference of the approximate topocentric, apparent azimuth of Sun and Moon (delta), at which the Sun is used as the reference point, in degrees and arcminutes as it happen at standard set time of the Sun. See Standard set time of the Sun, for further details.

D o Calculates the difference of the approximate geocentric, apparent elevation of Sun and Moon (delta), at which the Sun is used as the reference point, in degrees and arcminutes as it happen at standard rise time of the Sun. See Standard rise time of the Sun, for further details.

D s Calculates the difference of the approximate geocentric, apparent elevation of Sun and Moon (delta), at which the Sun is used as the reference point, in degrees and arcminutes as it happen at standard set time of the Sun. See Standard set time of the Sun, for further details.

E o Calculates the difference of the approximate geocentric, apparent azimuth of Sun and Moon (delta), at which the Sun is used as the reference point, in degrees and arcminutes as it happen at standard rise time of the Sun. See Standard rise time of the Sun, for further details.

E s Calculates the difference of the approximate geocentric, apparent azimuth of Sun and Moon (delta), at which the Sun is used as the reference point, in degrees and arcminutes as it happen at standard set time of the Sun. See Standard set time of the Sun, for further details.

F o, s Calculates the difference of the approximate astronomical midnight times of Sun and Moon (delta), at which the Sun is used as the reference point, as time value in hours and minutes as it happen at astronomical midnight time of the Sun. Results with a negative sign signify that the astronomical midnight time of the Sun is earlier than the astronomical midnight time of the Moon; thus the solar midnight is before the lunar midnight. Results with a positive sign signify that the astronomical midnight time of the Sun is later than the astronomical midnight time of the Moon; thus the solar midnight is after the lunar midnight. See Astronomical midnight time of the Sun, and Astronomical midnight time of the Moon, for further details.

G o, s Calculates the difference of the approximate astronomical noon times of Sun and Moon (delta), at which the Sun is used as the reference point, as time value in hours and minutes as it happen at astronomical noon time of the Sun. Results with a negative sign signify that the astronomical noon time of the Sun is earlier than the astronomical noon time of the Moon; thus the solar noon is before the lunar noon. Results with a positive sign signify that the astronomical noon time of the Sun is later than the astronomical noon time of the Moon; thus the solar noon is after the lunar noon. See Astronomical noon time of the Sun, and Astronomical noon time of the Moon, for further details.

H o Calculates the difference of the approximate standard rise times of Sun and Moon (delta), at which the Sun is used as the reference point, as time value in hours and minutes as it happen at standard rise time of the Sun. Results with a negative sign signify that the standard rise time of the Sun is earlier than the standard rise time of the Moon; thus the sunrise is before the moonrise. Results with a positive sign signify that the standard rise time of the Sun is later than the standard rise time of the Moon; thus the sunrise is after the moonrise. See Standard rise time of the Sun, and Standard rise time of the Moon, for further details.

H s Calculates the difference of the approximate standard set times of Sun and Moon (delta), at which the Sun is used as the reference point, as time value in hours and minutes as it happen at standard set time of the Sun. Results with a negative sign signify that the standard set time of the Sun is earlier than the standard set time of the Moon; thus the sunset is before the moonset. Results with a positive sign signify that the standard set time of the Sun is later than the standard set time of the Moon; thus the sunset is after the moonset. See Standard set time of the Sun, and Standard set time of the Moon, for further details.

I o, s Calculates the approximate topocentric, apparent elevation of the Sun in degrees and arcminutes as it happen at astronomical midnight time of the Sun (topocentric midnight height). See Astronomical midnight time of the Sun, for further details.

J o, s Calculates the approximate topocentric, apparent elevation of the Sun in degrees and arcminutes as it happen at astronomical midnight time of the Sun (topocentric midnight height). See Astronomical noon time of the Sun, for further details.

K o Calculates the approximate topocentric, apparent elevation of the Sun in degrees and arcminutes as it happen at standard rise time of the Sun (topocentric rise height). See Standard rise time of the Sun, for further details.

K s Calculates the approximate topocentric, apparent elevation of the Sun in degrees and arcminutes as it happen at standard set time of the Sun (topocentric set height). See Standard set time of the Sun, for further details.

L o Calculates the approximate topocentric, apparent azimuth of the Sun in degrees and arcminutes as it happen at standard rise time of the Sun (topocentric rise azimuth). The horizontal angular distance between the topocentric rise azimuth and the East direction is also known as the topocentric morning width of the Sun. See Standard rise time of the Sun, for further details.

L s Calculates the approximate topocentric, apparent azimuth of the Sun in degrees and arcminutes as it happen at standard set time of the Sun (topocentric set azimuth). The horizontal angular distance between the topocentric set azimuth and the West direction is also known as the topocentric evening width of the Sun. See Standard set time of the Sun, for further details.

M o, s Calculates the approximate geocentric, apparent elevation of the Sun in degrees and arcminutes as it happen at astronomical midnight time of the Sun (geocentric midnight height). See Astronomical midnight time of the Sun, for further details.

N o, s Calculates the approximate geocentric, apparent elevation of the Sun in degrees and arcminutes as it happen at astronomical midnight time of the Sun (geocentric midnight height). See Astronomical noon time of the Sun, for further details.

O o Calculates the approximate geocentric, apparent elevation of the Sun in degrees and arcminutes as it happen at standard rise time of the Sun (geocentric rise height). See Standard rise time of the Sun, for further details.

O s Calculates the approximate geocentric, apparent elevation of the Sun in degrees and arcminutes as it happen at standard set time of the Sun (geocentric set height). See Standard set time of the Sun, for further details.

P o Calculates the approximate geocentric, apparent azimuth of the Sun in degrees and arcminutes as it happen at standard rise time of the Sun (geocentric rise azimuth). The horizontal angular distance between the geocentric rise azimuth and the East direction is also known as the geocentric morning width of the Sun. See Standard rise time of the Sun, for further details.

P s Calculates the approximate geocentric, apparent azimuth of the Sun in degrees and arcminutes as it happen at standard set time of the Sun (geocentric set azimuth). The horizontal angular distance between the geocentric set azimuth and the West direction is also known as the geocentric evening width of the Sun. See Standard set time of the Sun, for further details.

Q o Calculates the approximate time when the length of the shadow cast by a vertical pole in the forenoon is equal the length of the pole. Nevertheless, the minimum length of the shadow is subtracted from the length of the shadow before comparing it with the length of the pole. See Fixed dates option --adjust-value=argument, how to change the shadow length factor.

Q s Calculates the approximate time when the length of the shadow cast by a vertical pole in the afternoon is equal the length of the pole. Nevertheless, the minimum length of the shadow is subtracted from the length of the shadow before comparing it with the length of the pole. People of Islamic faith, and that the people holding the Shafi school of jurisprudence, normally pray for the third time on the day at this clocktime, or some minutes later. These people commonly use the term Asr for this prayer time. See Astronomical noon time of the Sun, for more information. And note Fixed dates option --adjust-value=argument, how to change the shadow length factor.

Q u Calculates the approximate period while the center of the Sun is above a reference altitude, at which the length of the shadow cast by a vertical pole is of single or shorter length than the pole itself.

Q z Calculates the approximate period while the center of the Sun is below a reference altitude, at which a vertical pole either casts no shadow anymore, or casts a shadow that is longer than the single length of the pole itself.

R o Calculates the approximate time when the length of the shadow cast by a vertical pole at forenoon is twice the length of the pole. Nevertheless, the minimum length of the shadow is subtracted from the length of the shadow before comparing it with the length of the pole. See Fixed dates option --adjust-value=argument, how to change the shadow length factor.

R s Calculates the approximate time when the length of the shadow cast by a vertical pole in the afternoon is twice the length of the pole. Nevertheless, the minimum length of the shadow is subtracted from the length of the shadow before comparing it with the length of the pole. People of Islamic faith, and that the people holding the Hanafi school of jurisprudence, normally pray for the third time on the day at this clocktime, or some minutes later. These people commonly use the term Asr for this prayer time. See Astronomical noon time of the Sun, for more information. And note Fixed dates option --adjust-value=argument, how to change the shadow length factor.

R u Calculates the approximate period while the center of the Sun is above a reference altitude, at which the length of the shadow cast by a vertical pole is of double or shorter length than the pole itself.

R z Calculates the approximate period while the center of the Sun is below a reference altitude, at which a vertical pole either casts no shadow anymore, or casts a shadow that is longer than twice the length of the pole itself.

If no mode is given, Gcal automatically uses that mode, which is enabled by the mode character ‘5’. If a mode character is given that is not according to one of the ‘0...9, ‘a...z and ‘A...R characters, Gcal also automatically uses that mode, which is enabled by the mode character ‘5’.

Gcal represents the Sun oriented special texts depending on the selected mode using the following types and styles:

  1. Unsigned decimal based rational number value
    Unsigned decimal based rational number values are represented using the n.n... format by default. A ‘*’ character that is directly given before some mode characters causes Gcal to represent the value for another quantity. For the mode characters, which
    1. cause the calculation of Earth/Sun or Earth/Moon distances, the calculated distance is represented in kilometers.
    2. cause the calculation of phase angles of the Moon, the calculated phase angle is represented as a phase value in percents.

    If definite events happen, Gcal displays special event oriented texts instead of using the previously described representations. See Event texts of the Sun oriented special texts, where you can find the event oriented texts that are created for clocktime values, which are schematically and analogously used for the type of representation as it is described here.

  2. Signed decimal based rational number value
    Signed decimal based rational number values are represented using the +|-n.n... format by default. A ‘*’ character that is directly given before a mode character causes Gcal not to represent such values using another style.

    If definite events happen, Gcal displays special event oriented texts instead of using the previously described representations. See Event texts of the Sun oriented special texts, where you can find the event oriented texts that are created for clocktime values, which are schematically and analogously used for the type of representation as it is described here.

  3. Clocktime value
    Clocktime values are represented in hours and minutes, and that in the hh:mm 24-hour format by default. A ‘*’ character that is directly given before a mode character causes Gcal to represent the clocktime value using the 12-hour format, thus to provide it with a time suffix. See Actual local time %t[argument] special text, for more details about the above mentioned time value template.

    If definite events happen, Gcal displays special event oriented texts instead of using the previously described representations:

  4. Unsigned time value
    Unsigned time values, which mostly denote a period or interval of time, are represented in hours and minutes using the hhhmm' format by default. A ‘*’ character that is directly given before a mode character causes Gcal to represent the time value using another style, and that in decimal hours, i.e. in the hh.h... format.

    If definite events happen, Gcal displays special event oriented texts instead of using the previously described representations. See Event texts of the Sun oriented special texts, where you can find the event oriented texts that are created for clocktime values, which are schematically and analogously used for the type of representation as it is described here.

  5. Signed time value
    Signed time values, which mostly denote a period or interval of time, are represented in hours and minutes using the +|-hhhmm' format by default. A ‘*’ character that is directly given before a mode character causes Gcal to represent the time value using another style, and that in decimal hours, i.e. in the +|-hh.h... format.

    If definite events happen, Gcal displays special event oriented texts instead of using the previously described representations. See Event texts of the Sun oriented special texts, where you can find the event oriented texts that are created for clocktime values, which are schematically and analogously used for the type of representation as it is described here.

  6. Unsigned angular value
    Unsigned angular values are represented in degrees and arcminutes using the ddddmm' format by default. A ‘*’ character that is directly given before a mode character causes Gcal to represent the angular value using another style, and that in decimal degrees, i.e. in the ddd.d... format.

    If definite events happen, Gcal displays special event oriented texts instead of using the previously described representations. See Event texts of the Sun oriented special texts, where you can find the event oriented texts that are created for clocktime values, which are schematically and analogously used for the type of representation as it is described here.

  7. Signed angular value
    Signed angular values are represented in degrees and arcminutes using the +|-ddddmm' format by default. A ‘*’ character that is directly given before a mode character causes Gcal to represent the angular value using another style, and that in decimal degrees, i.e. in the +|-ddd.d... format.

    If definite events happen, Gcal displays special event oriented texts instead of using the previously described representations. See Event texts of the Sun oriented special texts, where you can find the event oriented texts that are created for clocktime values, which are schematically and analogously used for the type of representation as it is described here.

After the optional style and mode characters, the latitude and longitude of the geographic co-ordinates follows, for which the calculations must be made. They must be conform the ISO-6709:1983 standard representation of latitude and longitude for geographic point locations, so that the co-ordinate has to be declared like this:

All components of the co-ordinates must have leadings zeroes in case they have less digits than the templates shown above. Declared decimal seconds are not respected by Gcal. Heights which have a negative sign remain unrespected if Gcal determinates Sun and Moon data and times, respectively. In such a case, Gcal always uses the height +0. Latitude and longitude co-ordinates, and the height of the observer's location are connected without any separating characters, like ‘+40-075+61’, ‘+401213.1-0750015.1’ or ‘+40.20361-075.00417+0061’. See the pertinent literature for more details.

A time value [+|-]mmmm|hh:[mm], which is separated by a ‘,’ character, may trail the co-ordinate. Such a time value informs Gcal, about how many minutes mmmm respectively hours hh and minutes mm the geographic location is displaced from Universal time (UTC/GMT). This time displacement value defines the timezone, which is actually valid for this location. If summer- and wintertimes are respected for the location, you should include that change in time into the timezone value for the period in which the summertime is valid, by which the clock is put on during the summertime period — such a change is either subtracted from the timezone value for locations West of the prime meridian (Greenwich), or it is added for locations East of the prime meridian, because Gcal is actually unable to perform such operations automatically! See Actual local time %t[argument] special text, for more details about the above mentioned time value template. If no time displacement value is specified for a given co-ordinate, Gcal assumes a time displacement value of 0, which is equal to the actual Universal time (UTC/GMT).

The following table informs you about which type of representation is caused by a mode. The previously defined numbering scheme, as it has been used for the introduction of the types of representations, is used as key value in the column that holds the type of representation. The table also contains a column that shows whether a mode enables dynamical values, i.e. values that are depending on the respective clocktime (if you use the --time-offset=argument option, you can change the respective clocktime that is used for calculating such values). In a next table column, it is listed whether the given co-ordinate of the location influences the determination of a value, and the last column of the table gives you the information whether a given timezone value affects the values determination:

Mode Representation Type Dynamical Co-ordinate Timezone

0 3 No Yes Yes
1 3 No Yes Yes
2 3 or 4 No Yes Yes
3 3 or 4 No Yes Yes
4 3 or 4 No Yes Yes
5 3 or 4 No Yes Yes
6 3 or 4 No Yes Yes
7 3 or 4 No Yes Yes
8 3 or 4 No Yes Yes
9 3 or 4 No Yes Yes
a 7 Yes Yes Yes
b 6 Yes Yes Yes
c 7 Yes Yes Yes
d 6 Yes Yes Yes
e 4 Yes Yes Yes
f 1 or 1a Yes Yes Yes
g 6 Yes Yes Yes
h 6 Yes Yes Yes
i 6 Yes No No
j 7 Yes Yes Yes
k 6 Yes Yes Yes
l 7 Yes Yes Yes
m 6 Yes Yes Yes
n 4 Yes Yes Yes
o 1 or 1a Yes Yes Yes
p 6 Yes Yes Yes
q 6 Yes Yes Yes
r 2 Yes No No
s 3 Yes Yes Yes
t 3 Yes No No
u 1 Yes No No
v 1 Yes No No
w 5 Yes No Yes
x 7 Yes Yes Yes
y 7 Yes Yes Yes
z 7 Yes Yes Yes
A 7 Yes Yes Yes
B 7 No Yes Yes
C 7 No Yes Yes
D 7 No Yes Yes
E 7 No Yes Yes
F 5 No Yes Yes
G 5 No Yes Yes
H 5 No Yes Yes
I 7 No Yes Yes
J 7 No Yes Yes
K 7 No Yes Yes
L 6 No Yes Yes
M 7 No Yes Yes
N 7 No Yes Yes
O 7 No Yes Yes
P 6 No Yes Yes
Q 3 or 4 No Yes Yes
R 3 or 4 No Yes Yes

And now some examples to these special texts:

The text ‘Sunrise at %o+5158+00738,120  in MS, BRD will be expanded to
==> ‘Sunrise at 05:16 in MS, BRD, in case the actual system date is the 1st June 1998.
The text ‘Sunset at %s*5+5158+00738,120  in MS, BRD will be expanded to
==> ‘Sunset at 09:39pm in MS, BRD, in case the actual system date is the 1st June 1998.
The text ‘Sun visible %u5+5158+00738,120  in MS, BRD will be expanded to
==> ‘Sun visible 16h24' in MS, BRD, in case the actual system date is the 1st June 1998.
The text ‘Sun non-visible %z*+5158+00738,120  in MS, BRD will be expanded to
==> ‘Sun non-visible 7.607 in MS, BRD, in case the actual system date is the 1st June 1998.
The text ‘Sun azimuth 0 o'clock=%s*a+5158+00738,120  in MS, BRD will be expanded to
==> ‘Sun azimuth 0 o'clock=339d16' in MS, BRD, in case the actual system date is the 1st June 1998.
The text ‘Equation of time %ot+00+000=%o*w+00+000,120  BRD will be expanded to
==> ‘Equation of time +16h00'=+00h02'13.201" BRD, in case you call Gcal with the --time-offset=16: and --precise options and the actual system date is the 1st June 1998.
The text ‘Julian date at %ot+00+000 =%ou+00+000 will be expanded to
==> ‘Julian date at +10h15'=2450965.927, in case you call Gcal with the --time-offset=10:15 option and the actual system date is the 1st June 1998.

Here is a list that reports about the used reference systems in a short manner, describes other aspects that are unmentioned now, and informs about the lacks and limitations that are existing for the Sun oriented special texts:

Please also note the following references:

All Sun oriented special texts must always be trailed by a whitespace character which is removed in output!


Next: , Previous: Sun data, Up: Replacements with other argument
G.2.2.6 Moon data %[format]?argument special texts

%[format]([*][mode]ISO-6709:1983-co-ordinate[,[+|-]mmmm|hh:[mm]] references the approximate time of moonrise by default,
%[format])[*][mode]ISO-6709:1983-co-ordinate[,[+|-]mmmm|hh:[mm]] references the approximate time of moonset by default,
%[format][[*][mode]ISO-6709:1983-co-ordinate[,[+|-]mmmm|hh:[mm]] references the approximate period of visibility of the Moon (lunar day length) by default,
%[format]][*][mode]ISO-6709:1983-co-ordinate[,[+|-]mmmm|hh:[mm]] references the approximate period of non-visibility of the Moon (lunar night length) by default.

All these special texts can be used for at pleasure any geographic point location, i.e. it is possible to determine different astronomical values for any location on the globe, and that for at pleasure any clocktime with a resolution of a single minute within the period of the years AD 1 until AD 9999, that is respected by Gcal.

The selection which value has to be calculated by these special texts is done by specifying the mode part of the preceding argument. Actually, exactly 61 different modes can be used that are represented by the ‘0...9, ‘a...z and ‘A...Y characters, and which create different kind of results that are depending on the special text used. First of all, here is a table in which all usable modes are described and explained sufficiently. You can also see from this table, which Moon oriented special text or texts are corresponding to which mode, i.e. cause the determination of an astronomical value as it is described in the table:

Mode Special text Description

0 (, ) Calculates the approximate midnight time of the Moon. The astronomical midnight time of the Moon is at that clocktime, when the Moon holds an azimuth (horizontal angular distance between the vertical circle, that passes the Moon, and the North point) of either precisely 0 degrees of precisely 180 degrees, which depends on the season and the geographical location. At that clocktime, the Moon is close its lowest culmination point, i.e. close the lowest point below or above the horizontal plane the Moon transits during this day. Nevertheless, there is exactly one day during a synodic month (or lunation) —i.e. the mean time between two consecutive conjunctions (or New Moon phases)— at which no lunar midnight happens, because the Moon revolves the Earth within 24 hours and 50 minutes on the average — which also means, that the Moon rises on the average 50 minutes later each day.

1 (, ) Calculates the approximate noon time of the Moon. The astronomical noon time of the Moon is at that clocktime, when the Moon holds an azimuth of either precisely 180 degrees of precisely 0 degrees, which depends on the season and the geographical location. At that clocktime, the Moon is close its highest culmination point, i.e. close the highest point above or below the horizontal plane the Moon transits during this day. Nevertheless, there is exactly one day during a synodic month at which no lunar noon happens.

2 ( Calculates the approximate time when the center of the Moon passes a reference altitude which is between about 54 and 61 arcminutes above a mathematical-geocentric horizon before lunar noon time; thus rising. A mathematical horizon is a purely geometrically-built horizon which disregards the phenomenon of refraction as it arises in reality by the influence of the Earth's atmosphere. A geocentrical horizon is the horizontal plane that passes through the Earth's center, orthogonal to the observer's local vertical. In the further context, the shorter term mathematical horizon is used which actually means the mathematical-geocentric horizon. The above mentioned reference altitude is computed from the value of the Moon's parallax as it appear at that clocktime. Nevertheless, there is exactly one day during a synodic month at which no such moonrise happens.

2 ) Calculates the approximate time when the center of the Moon passes a reference altitude which is between about 54 and 61 arcminutes above a mathematical horizon after lunar noon time; thus setting. The above mentioned reference altitude is computed from the value of the Moon's parallax as it appear at that clocktime. Nevertheless, there is exactly one day during a synodic month at which no such moonset happens.

2 [ Calculates the approximate period while the center of the Moon is above a reference altitude which is between about 54 and 61 arcminutes above a mathematical horizon; thus is visible.

2 ] Calculates the approximate period while the center of the Moon is below a reference altitude which is between about 54 and 61 arcminutes above a mathematical horizon; thus is non-visible.

3 ( Calculates the approximate time when the upper limb of the Moon passes a reference altitude which is between about 54 and 61 arcminutes above a mathematical horizon before lunar noon time; thus rising. The above mentioned reference altitude is computed from the respective values of the Moon's semidiameter and Moon's parallax as they appear at that clocktime. If the reference altitude that is referring to the Moon's upper limb is converted to a reference altitude that is referring to the Moon's center, this results in a value which is between about 39 and 44 arcminutes above the geocentric horizon. Nevertheless, there is exactly one day during a synodic month at which no such moonrise happens.

3 ) Calculates the approximate time when the upper limb of the Moon passes a reference altitude which is between about 54 and 61 arcminutes above a mathematical horizon after lunar noon time; thus setting. The above mentioned reference altitude is computed from the respective values of the Moon's semidiameter and Moon's parallax as they appear at that clocktime. Nevertheless, there is exactly one day during a synodic month at which no such moonset happens.

3 [ Calculates the approximate period while the upper limb of the Moon is above a reference altitude which is between about 54 and 61 arcminutes above a mathematical horizon; thus is visible.

3 ] Calculates the approximate period while the upper limb of the Moon is below a reference altitude which is between about 54 and 61 arcminutes above a mathematical horizon; thus is non-visible.

4 ( Calculates the approximate time when the center of the Moon passes a reference altitude which is between about 20 and 27 arcminutes above the geocentric horizon before lunar noon time; thus rising. The phenomenon of refraction is already respected in this as it arises in reality by the influence of the Earth's atmosphere, and that with the standard value of 34 arcminutes, which can indirectly be changed by using the --atmosphere option. Fixed dates option --atmosphere=air-pressure[,temperature], how to change the base data of the atmosphere, so that the atmospheric conditions as defined by it are used to calculate the amount of refraction. The above mentioned reference altitude is computed from the respective values of the Moon's parallax and (standard) refraction as they appear at that clocktime. Nevertheless, there is exactly one day during a synodic month at which no such moonrise happens.

4 ) Calculates the approximate time when the center of the Moon passes a reference altitude which is between about 20 and 27 arcminutes above the geocentric horizon after lunar noon time; thus setting. The phenomenon of refraction is already respected in this as it arises in reality by the influence of the Earth's atmosphere, and that with the standard value of 34 arcminutes, which can indirectly be changed by using the --atmosphere option. The above mentioned reference altitude is computed from the respective values of the Moon's parallax and (standard) refraction as they appear at that clocktime. Nevertheless, there is exactly one day during a synodic month at which no such moonset happens.

4 [ Calculates the approximate period while the center of the Moon is above a reference altitude which is between about 20 and 27 arcminutes above the geocentric horizon; thus is visible.

4 ] Calculates the approximate period while the center of the Moon is below a reference altitude which is between about 20 and 27 arcminutes above the geocentric horizon; thus is non-visible.

5 ( Calculates the approximate time when the upper limb of the Moon passes a reference altitude which is between about 20 and 27 arcminutes above the geocentric horizon before lunar noon time; thus rising. This kind of rise time calculation is done according to the standard calculation method as it is commonly used internationally. The phenomenon of refraction is already respected in this as it arises in reality by the influence of the Earth's atmosphere, and that with the standard value of 34 arcminutes, which can indirectly be changed by using the --atmosphere option. Fixed dates option --atmosphere=air-pressure[,temperature], how to change the base data of the atmosphere, so that the atmospheric conditions as defined by it are used to calculate the amount of refraction. The above mentioned reference altitude is computed from the respective values of the Moon's semidiameter, Moon's parallax and (standard) refraction as they appear at that clocktime. If the reference altitude that is referring to the Moon's upper limb is converted to a reference altitude that is referring to the Moon's center, this results in a value which is between about 5 and 10 arcminutes above the geocentric horizon. Nevertheless, there is exactly one day during a synodic month at which no such moonrise happens.

5 ) Calculates the approximate time at which the upper limb of the Moon passes a reference altitude which is between about 20 and 27 arcminutes above the geocentric horizon after lunar noon time; thus setting. This kind of set time calculation is done according to the standard calculation method as it is commonly used internationally. The phenomenon of refraction is already respected in this as it arises in reality by the influence of the Earth's atmosphere, and that with the standard value of 34 arcminutes, which can indirectly be changed by using the --atmosphere option. The above mentioned reference altitude is computed from the respective values of the Moon's semidiameter, Moon's parallax and (standard) refraction as they appear at that clocktime. Nevertheless, there is exactly one day during a synodic month at which no such moonset happens.

5 [ Calculates the approximate period while the upper limb of the Moon is above a reference altitude which is between about 20 and 27 arcminutes above the geocentric horizon; thus is visible. This kind of visibility period calculation is done according to the standard calculation method as it is commonly used internationally.

5 ] Calculates the approximate period while the upper limb of the Moon is below a reference altitude which is between about 20 and 27 arcminutes above the geocentric horizon; thus is non-visible. This kind of non-visibility period calculation is done according to the standard calculation method as it is commonly used internationally.

6 (, ) Calculates the approximate topocentric, apparent horizontal parallax of the Moon in degrees and arcminutes as it happen at civil midnight time. The Moon's parallax states the diameter of the Earth as it is seen from the surface of the Moon. Observations of celestial objects that are done from the surface of the Earth yield in topocentrically based data. The locations of the celestial bodies are often at another place if the data is topocentrically determined instead of determine it geocentrically, i.e. at the fictitious center of the Earth. This is mainly caused by the refraction, which raises a celestial body to another location as it is been in reality. Because the terrestrial globe flattens towards the pole caps and therefore cannot be taken as an ideally shaped sphere, the individual Earth radius between the observer's location and the center of the Earth also affects the computation of topocentrically based data.

7 (, ) Calculates the approximate topocentric, apparent semidiameter of the Moon in degrees and arcminutes as it happen at civil midnight time.

8 (, ) Calculates the approximate topocentric, apparent brightness of the Moon in magnitude units as it happen at civil midnight time. The magnitude (Latin term magnitudo, abbreviated m) is used to define the brightness of a star, and is a non-metrical value. The difference between two consecutive magnitudes is 1 to 2.512. Therefore, a star with the brightness of 1m is 2.512 times brighter than a star of 2m. A negative magnitude denotes a very bright star, for example almost -27m for the Sun, whereas the hardly visible planet Pluto has a magnitude of a bit more than +14m. The Full Moon has a visual brightness of about -12m.55.

9 (, ) Calculates the approximate topocentric, apparent phase angle of the Moon in range 0.0...1.0 as it happen at civil midnight time.

a (, ) Calculates the approximate topocentric, apparent elevation of the Moon, thus the vertical angular distance between the Moon's center and the horizon, in degrees and arcminutes as it happen at civil midnight time. Results with a negative sign signify that the Moon's center is below the horizon at the moment, and results with a positive sign mean that the momentary center of the Moon is above the horizon.

b (, ) Calculates the approximate topocentric, apparent azimuth of the Moon in degrees and arcminutes as it happen at civil midnight time.

c (, ) Calculates the approximate topocentric, apparent declination of the Moon, thus the vertical angular distance between the Moon's center and the celestial equator, in degrees and arcminutes as it happen at civil midnight time. Results with a negative sign signify that the Moon's center is below the celestial equator at the moment, and results with a positive sign mean that the momentary center of the Moon is above the celestial equator.

d (, ) Calculates the approximate topocentric, apparent ecliptic longitude of the Moon, thus the horizontal angular distance between the Moon's center and the vernal equinox point on the ecliptic (the zodiacal line or Sun's orbit), in degrees and arcminutes as it happen at civil midnight time.

e (, ) Calculates the approximate topocentric, apparent ecliptic latitude of the Moon, thus the vertical angular distance between the Moon's center and the ecliptic (zodiacal line/Sun's orbit), in degrees and arcminutes as it happen at civil midnight time. Results with a negative sign signify that the Moon's center is North of the ecliptic at the moment, and results with a positive sign mean that the momentary center of the Moon is South of the ecliptic.

f (, ) Calculates the approximate topocentric, apparent right ascension of the Moon, thus the horizontal angular distance between the Moon's center and the hour circle that passes through the vernal equinox point on the ecliptic, as time value in hours and minutes as it happen at civil midnight time.

g (, ) Calculates the approximate topocentric, apparent distance of the Moon from the Earth in mean Earth equator radii as it happen at civil midnight time. The mean radius of Earth at the equator is about 6,378.137 kilometer.

h (, ) Calculates the approximate topocentric, apparent elongation of the Moon, thus the horizontal angular distance between the Moon's center and the Sun's center, in degrees and arcminutes as it happen at civil midnight time.

i (, ) Calculates the approximate refraction of the Earth's atmosphere in degrees and arcminutes as it happen at civil midnight time.

j (, ) Calculates the approximate geocentric, apparent horizontal parallax of the Moon in degrees and arcminutes as it happen at civil midnight time.

k (, ) Calculates the approximate geocentric, apparent semidiameter of the Moon in degrees and arcminutes as it happen at civil midnight time.

l (, ) Calculates the approximate geocentric, apparent brightness of the Moon in magnitude units as it happen at civil midnight time.

m (, ) Calculates the approximate geocentric, apparent phase angle of the Moon in range 0.0...1.0 as it happen at civil midnight time.

n (, ) Calculates the approximate geocentric, apparent elevation of the Moon in degrees and arcminutes as it happen at civil midnight time. Results with a negative sign signify that the Moon's center is below the horizon at the moment, and results with a positive sign mean that the momentary center of the Moon is above the horizon.

o (, ) Calculates the approximate geocentric, apparent azimuth of the Moon in degrees and arcminutes as it happen at civil midnight time.

p (, ) Calculates the approximate geocentric, apparent declination of the Moon in degrees and arcminutes as it happen at civil midnight time. Results with a negative sign signify that the Moon's center is below the celestial equator at the moment, and results with a positive sign mean that the momentary center of the Moon is above the celestial equator.

q (, ) Calculates the approximate geocentric, apparent ecliptic longitude of the Moon in degrees and arcminutes as it happen at civil midnight time.

r (, ) Calculates the approximate geocentric, apparent ecliptic latitude of the Moon in degrees and arcminutes as it happen at civil midnight time. Results with a negative sign signify that the Moon's center is North of the ecliptic at the moment, and results with a positive sign mean that the momentary center of the Moon is South of the ecliptic.

s (, ) Calculates the approximate geocentric, apparent right ascension of the Moon as time value in hours and minutes as it happen at civil midnight time.

t (, ) Calculates the approximate geocentric, apparent distance of the Moon from the Earth in mean Earth equator radii as it happen at civil midnight time.

u (, ) Calculates the approximate geocentric, apparent elongation of the Moon in degrees and arcminutes as it happen at civil midnight time.

v (, ) Calculates the approximate delta-t in seconds as it happen at civil midnight time. Delta-t is the difference between the Terrestrial Dynamical time (abbreviated by TDT), that was formerly known as Ephemeris time (abbreviated by ET), and the Universal time (UT). Thus, ‘delta-t == TDT - UT.

w (, ) Calculates the approximate, apparent location oriented sidereal time (local sidereal time (LAST), also known as local star time) in hours and minutes as it happen at civil midnight time. A star day is the period between two consecutive upper culminations of the vernal equinox point on the ecliptic in the meridian of the observer's location. Therefore, the local star time is the momentary period, which is past between the last upper culmination of the vernal equinox point in the meridian of the observer's location (the momentary hour angle of the vernal equinox point), thus the right ascension of the stars in the observer's meridian at the moment.

x (, ) Outputs the base time as time value in hours and minutes, for which the dynamical, i.e. depending on the respective clocktime, astronomical data and times of the Moon are calculated. Without a given --time-offset=argument option, the astronomical data and times of the Moon are always calculated for 0 o'clock Universal time (UTC/GMT). See Calendar option --time-offset=argument, for further details.

y (, ) Calculates the approximate Julian date in days as it happen at civil midnight time. See Julian day number, for further information about the Julian date.

z (, ) Calculates the approximate Julian Ephemeris date, thus a Julian date that is corrected by delta-t, in days as it happen at civil midnight time.

A (, ) Calculates the difference of the approximate topocentric, apparent elevation of Moon and Sun (delta), at which the Moon is used as the reference point, in degrees and arcminutes as it happen at civil midnight time. Results with a negative sign signify that the momentary center of the Moon is at an elevation that is below the momentary elevation of the Sun's center; thus the Moon is lower than the Sun. Results with a positive sign signify that the momentary center of the Moon is at an elevation that is above the momentary elevation of the Sun's center; thus the Moon is higher than the Sun.

B (, ) Calculates the difference of the approximate topocentric, apparent azimuth of Moon and Sun (delta), at which the Moon is used as the reference point, in degrees and arcminutes as it happen at civil midnight time. The result specifies the horizontal angular distance, by which the momentary center of the Moon is distant from the momentary Sun's center, and that measured at the vertical circles that pass the Moon and the North point and the Sun and the North point. Results with a negative sign signify that the Sun is to the right (clockwise) of the Moon if one looks to the Moon — or alternatively expressed, that the Moon is to the left (anti-clockwise) of the Sun. Results with a positive sign signify that the Sun is to the left (anti-clockwise) of the Moon if one looks to the Moon — or alternatively expressed, that the Moon is to the right (clockwise) of the Sun.

C (, ) Calculates the difference of the approximate geocentric, apparent elevation of Moon and Sun (delta), at which the Moon is used as the reference point, in degrees and arcminutes as it happen at civil midnight time.

D (, ) Calculates the difference of the approximate geocentric, apparent azimuth of Moon and Sun (delta), at which the Moon is used as the reference point, in degrees and arcminutes as it happen at civil midnight time.

E ( Calculates the difference of the approximate topocentric, apparent elevation of Moon and Sun (delta), at which the Moon is used as the reference point, in degrees and arcminutes as it happen at standard rise time of the Moon. See Standard rise time of the Moon, for further details.

E ) Calculates the difference of the approximate topocentric, apparent elevation of Moon and Sun (delta), at which the Moon is used as the reference point, in degrees and arcminutes as it happen at standard set time of the Moon. See Standard set time of the Moon, for further details.

F ( Calculates the difference of the approximate topocentric, apparent azimuth of Moon and Sun (delta), at which the Moon is used as the reference point, in degrees and arcminutes as it happen at standard rise time of the Moon. See Standard rise time of the Moon, for further details.

F ) Calculates the difference of the approximate topocentric, apparent azimuth of Moon and Sun (delta), at which the Moon is used as the reference point, in degrees and arcminutes as it happen at standard set time of the Moon. See Standard set time of the Moon, for further details.

G ( Calculates the difference of the approximate geocentric, apparent elevation of Moon and Sun (delta), at which the Moon is used as the reference point, in degrees and arcminutes as it happen at standard rise time of the Moon. See Standard rise time of the Moon, for further details.

G ) Calculates the difference of the approximate geocentric, apparent elevation of Moon and Sun (delta), at which the Moon is used as the reference point, in degrees and arcminutes as it happen at standard set time of the Moon. See Standard set time of the Moon, for further details.

H ( Calculates the difference of the approximate geocentric, apparent azimuth of Moon and Sun (delta), at which the Moon is used as the reference point, in degrees and arcminutes as it happen at standard rise time of the Moon. See Standard rise time of the Moon, for further details.

H ) Calculates the difference of the approximate geocentric, apparent azimuth of Moon and Sun (delta), at which the Moon is used as the reference point, in degrees and arcminutes as it happen at standard set time of the Moon. See Standard set time of the Moon, for further details.

I (, ) Calculates the difference of the approximate astronomical midnight times of Moon and Sun (delta), at which the Moon is used as the reference point, as time value in hours and minutes as it happen at astronomical midnight time of the Moon. Results with a negative sign signify that the astronomical midnight time of the Moon is earlier than the astronomical midnight time of the Sun; thus the lunar midnight is before the solar midnight. Results with a positive sign signify that the astronomical midnight time of the Moon is later than the astronomical midnight time of the Sun; thus the lunar midnight is after the solar midnight. See Astronomical midnight time of the Moon, and Astronomical midnight time of the Sun, for further details.

J (, ) Calculates the difference of the approximate astronomical noon times of Moon and Sun (delta), at which the Moon is used as the reference point, as time value in hours and minutes as it happen at astronomical noon time of the Moon. Results with a negative sign signify that the astronomical noon time of the Moon is earlier than the astronomical noon time of the Sun; thus the lunar noon is before the solar noon. Results with a positive sign signify that the astronomical noon time of the Moon is later than the astronomical noon time of the Sun; thus the lunar noon is after the solar noon. See Astronomical noon time of the Moon, and Astronomical noon time of the Sun, for further details.

K ( Calculates the difference of the approximate standard rise times of Moon and Sun (delta), at which the Moon is used as the reference point, as time value in hours and minutes as it happen at standard rise time of the Moon. Results with a negative sign signify that the standard rise time of the Moon is earlier than the standard rise time of the Sun; thus the moonrise is before the sunrise. Results with a positive sign signify that the standard rise time of the Moon is later than the standard rise time of the Sun; thus the moonrise is after the sunrise. See Standard rise time of the Moon, and Standard rise time of the Sun, for further details.

K ) Calculates the difference of the approximate standard set times of Moon and Sun (delta), at which the Moon is used as the reference point, as time value in hours and minutes as it happen at standard set time of the Moon. Results with a negative sign signify that the standard set time of the Moon is earlier than the standard set time of the Sun; thus the moonset is before the sunset. Results with a positive sign signify that the standard set time of the Moon is later than the standard set time of the Sun; thus the moonset is after the sunset. See Standard set time of the Moon, and Standard set time of the Sun, for further details.

L (, ) Calculates the approximate topocentric, apparent elevation of the Moon in degrees and arcminutes as it happen at astronomical midnight time of the Moon (topocentric midnight height). See Astronomical midnight time of the Moon, for further details.

M (, ) Calculates the approximate topocentric, apparent phase angle of the Moon in range 0.0...1.0 as it happen at astronomical midnight time of the Moon (topocentric midnight phase angle). See Astronomical midnight time of the Moon, for further details.

N (, ) Calculates the approximate topocentric, apparent elevation of the Moon in degrees and arcminutes as it happen at astronomical noon time of the Moon (topocentric noon height). See Astronomical noon time of the Moon, for further details.

O (, ) Calculates the approximate topocentric, apparent phase angle of the Moon in range 0.0...1.0 as it happen at astronomical noon time of the Moon (topocentric noon phase angle). See Astronomical noon time of the Moon, for further details.

P ( Calculates the approximate topocentric, apparent elevation of the Moon in degrees and arcminutes as it happen at standard rise time of the Moon (topocentric rise height). See Standard rise time of the Moon, for further details.

P ) Calculates the approximate topocentric, apparent elevation of the Moon in degrees and arcminutes as it happen at standard set time of the Moon (topocentric set height). See Standard set time of the Moon, for further details.

Q ( Calculates the approximate topocentric, apparent azimuth of the Moon in degrees and arcminutes as it happen at standard rise time of the Moon (topocentric rise azimuth). The horizontal angular distance between the topocentric rise azimuth and the East direction is also known as the topocentric rise width of the Moon. See Standard rise time of the Moon, for further details.

Q ) Calculates the approximate topocentric, apparent azimuth of the Moon in degrees and arcminutes as it happen at standard set time of the Moon (topocentric set azimuth). The horizontal angular distance between the topocentric set azimuth and the West direction is also known as the topocentric set width of the Moon. See Standard set time of the Moon, for further details.

R ( Calculates the approximate topocentric, apparent phase angle of the Moon in range 0.0...1.0 as it happen at standard rise time of the Moon (topocentric rise phase angle). See Standard rise time of the Moon, for further details.

R ) Calculates the approximate topocentric, apparent phase angle of the Moon in range 0.0...1.0 as it happen at standard set time of the Moon (topocentric set phase angle). See Standard set time of the Moon, for further details.

S (, ) Calculates the approximate geocentric, apparent elevation of the Moon in degrees and arcminutes as it happen at astronomical midnight time of the Moon (geocentric midnight height). See Astronomical midnight time of the Moon, for further details.

T (, ) Calculates the approximate geocentric, apparent phase angle of the Moon in range 0.0...1.0 as it happen at astronomical midnight time of the Moon (geocentric midnight phase angle). See Astronomical midnight time of the Moon, for further details.

U (, ) Calculates the approximate geocentric, apparent elevation of the Moon in degrees and arcminutes as it happen at astronomical noon time of the Moon (geocentric noon height). See Astronomical noon time of the Moon, for further details.

V (, ) Calculates the approximate geocentric, apparent phase angle of the Moon in range 0.0...1.0 as it happen at astronomical noon time of the Moon (geocentric noon phase angle). See Astronomical noon time of the Moon, for further details.

W ( Calculates the approximate geocentric, apparent elevation of the Moon in degrees and arcminutes as it happen at standard rise time of the Moon (geocentric rise height). See Standard rise time of the Moon, for further details.

W ) Calculates the approximate geocentric, apparent elevation of the Moon in degrees and arcminutes as it happen at standard set time of the Moon (geocentric set height). See Standard set time of the Moon, for further details.

X ( Calculates the approximate geocentric, apparent azimuth of the Moon in degrees and arcminutes as it happen at standard rise time of the Moon (geocentric rise azimuth). The horizontal angular distance between the geocentric rise azimuth and the East direction is also known as the geocentric rise width of the Moon. See Standard rise time of the Moon, for further details.

X ) Calculates the approximate geocentric, apparent azimuth of the Moon in degrees and arcminutes as it happen at standard set time of the Moon (geocentric set azimuth). The horizontal angular distance between the geocentric set azimuth and the West direction is also known as the geocentric set width of the Moon. See Standard set time of the Moon, for further details.

Y ( Calculates the approximate geocentric, apparent phase angle of the Moon in range 0.0...1.0 as it happen at standard rise time of the Moon (geocentric rise phase angle). See Standard rise time of the Moon, for further details.

Y ) Calculates the approximate geocentric, apparent phase angle of the Moon in range 0.0...1.0 as it happen at standard set time of the Moon (geocentric set phase angle). See Standard set time of the Moon, for further details.

If no mode is given, Gcal automatically uses that mode, which is enabled by the mode character ‘5’. If a mode character is given that is not according to one of the ‘0...9, ‘a...z and ‘A...Y characters, Gcal also automatically uses that mode, which is enabled by the mode character ‘5’.

Depending on the selected mode, Gcal represents the Moon oriented special texts using the same types and styles as they are used by the Sun oriented special texts, these are analogously valid! See Representation of the Sun oriented special texts, for the detailed description of the different types of representation used by the Sun oriented special texts, which are likewise valid for the Moon oriented special texts.

The argument the Moon oriented special texts must have is exactly equivalent the argument the Sun oriented special texts must have! See Arguments of the Sun oriented special texts, for the detailed description of the components of the argument which also has to be given to the Moon oriented special texts.

The following table informs you about which type of representation is caused by a mode. The previously defined numbering scheme, as it has been used for the introduction of the types of representation, is used as key value in the column that holds the type of representation. The table also contains a column that shows whether a mode enables dynamical values, i.e. values that are depending on the respective clocktime (if you use the --time-offset=argument option, you can change the respective clocktime that is used for calculating such values). In a next table column, it is listed whether the given co-ordinate of the location influences the determination of a value, and the last column of the table gives you the information whether a given timezone value affects the values determination:

Mode Representation Type Dynamical Co-ordinate Timezone

0 3 No Yes Yes
1 3 No Yes Yes
2 3 or 4 No Yes Yes
3 3 or 4 No Yes Yes
4 3 or 4 No Yes Yes
5 3 or 4 No Yes Yes
6 6 Yes Yes Yes
7 6 Yes Yes Yes
8 2 Yes Yes Yes
9 1 or 1b Yes Yes Yes
a 7 Yes Yes Yes
b 6 Yes Yes Yes
c 7 Yes Yes Yes
d 6 Yes Yes Yes
e 7 Yes Yes Yes
f 4 Yes Yes Yes
g 1 or 1a Yes Yes Yes
h 6 Yes Yes Yes
i 6 Yes No No
j 6 Yes Yes Yes
k 6 Yes Yes Yes
l 2 Yes Yes Yes
m 1 or 1b Yes Yes Yes
n 7 Yes Yes Yes
o 6 Yes Yes Yes
p 7 Yes Yes Yes
q 6 Yes Yes Yes
r 7 Yes Yes Yes
s 4 Yes Yes Yes
t 1 or 1a Yes Yes Yes
u 6 Yes Yes Yes
v 2 Yes No No
w 3 Yes Yes Yes
x 3 Yes No No
y 1 Yes No No
z 1 Yes No No
A 7 Yes Yes Yes
B 7 Yes Yes Yes
C 7 Yes Yes Yes
D 7 Yes Yes Yes
E 7 No Yes Yes
F 7 No Yes Yes
G 7 No Yes Yes
H 7 No Yes Yes
I 5 No Yes Yes
J 5 No Yes Yes
K 5 No Yes Yes
L 7 No Yes Yes
M 1 or 1b No Yes Yes
N 7 No Yes Yes
O 1 or 1b No Yes Yes
P 7 No Yes Yes
Q 6 No Yes Yes
R 1 or 1b No Yes Yes
S 7 No Yes Yes
T 1 or 1b No Yes Yes
U 7 No Yes Yes
V 1 or 1b No Yes Yes
W 7 No Yes Yes
X 6 No Yes Yes
Y 1 or 1b No Yes Yes

And now some examples to these special texts:

The text ‘Moonrise at %(+5158+00738,120  in MS, BRD will be expanded to
==> ‘Moonrise at 12:21 in MS, BRD, in case the actual system date is the 1st June 1998.
The text ‘Moonset at %)*5+5158+00738,120  in MS, BRD will be expanded to
==> ‘Moonset at 01:53am in MS, BRD, in case the actual system date is the 1st June 1998.
The text ‘Moon visible %[5+5158+00738,120  in MS, BRD will be expanded to
==> ‘Moon visible 13h32' in MS, BRD, in case the actual system date is the 1st June 1998.
The text ‘Moon non-visible %]*+5158+00738,120  in MS, BRD will be expanded to
==> ‘Moon non-visible 10.469 in MS, BRD, in case the actual system date is the 1st June 1998.
The text ‘Moon azimuth 0 o'clock=%(*a+5158+00738,120  in MS, BRD will be expanded to
==> ‘Moon azimuth 0 o'clock=267d37' in MS, BRD, in case the actual system date is the 1st June 1998.
The text ‘Moonphase %(x+00+000 =%(*m+5158+00738,120 % in MS, BRD will be expanded to
==> ‘Moonphase +16h00'=45.248% in MS, BRD, in case you call Gcal with the --time-offset=16: option and the actual system date is the 1st June 1998.
The text ‘Julian date at %(x+00+000 =%(y+00+000 will be expanded to
==> ‘Julian date at +10h15'=2450965.927, in case you call Gcal with the --time-offset=10:15 option and the actual system date is the 1st June 1998.

Here is a list that reports about the used reference systems in a short manner, describes other aspects that are unmentioned now, and informs about the lacks and limitations that are existing for the Moon oriented special texts:

Please also note the following references:

All Moon oriented special texts must always be trailed by a whitespace character which is removed in output!


Previous: Moon data, Up: Replacements with other argument
G.2.2.7 Environment variable %[format]-[argument] special text

%[format]-[argument] references the contents of an environment variable, e.g.:

The text ‘I am `%-USER '-user will be expanded to
==> ‘I am `guest'-user, in case you logged-in as guest on your system.

This special text must always be trailed by a whitespace character which is removed in output!


Previous: Replacements with other argument, Up: Replacements

G.2.3 Replacements without any argument %? special texts

Apart from further useful difference values, the text of a fixed date can be provided with different texts used for highlighting.


Next: , Previous: Replacements without any argument, Up: Replacements without any argument
G.2.3.1 Difference value %[format]? special texts

The use of the other difference values as listed here is to calculate distance values between two dates. In case these special texts are directly lead by a ‘-’ character, e.g. ‘-%d’, Gcal switches the sign of the computed value.

You may depreciate the special meaning of the ‘-’ character —in case this character itself is needed— by placing a ‘\’ (backslash) character before it, e.g. ‘\-’. If you need the ‘\-’ characters themselves, you have to protect the ‘\’ (backslash) character by another ‘\’ (backslash) character, e.g. ‘\\-’.

The following other difference values %[format]? special texts are respected:

%d
Specifies the current respectively queried day relative to the actual system date (==today), e.g.:
The resource file line ‘0 %d days gone will be expanded to
==> ‘-10 days gone, in case you call Gcal with the -c10- option and no command.

%w
Specifies the current respectively queried week relative to the actual system date (==today). Started weeks are counted as complete weeks.
%m
Specifies the current respectively queried month relative to the actual system date (==today). Started months are counted as complete months.
%y
Specifies the current respectively queried year relative to the actual system date (==today). Started years are counted as complete years. This special text must always be trailed by a whitespace character which is removed in output!

An example:

Supposing, the actual system date is the 4th September 1999. To calculate, how many days, weeks, months and years are between the actual system date and the birthday of a person, who is born on 21st September 1962, Gcal can be called as follows:

     

$ gcal -f/dev/null -Ux -u -#'19620921 %y %m %w %d~' 1962 -| -| -37 -444 -1928 -13497 -| $ gcal -f/dev/null -Ux -u -#'19620921 \\-%y \-%m %w -%d~' 1962 -| -| \--37 --444 -1928 13497 -| $ gcal -f/dev/null -Ux -u -#'00000904 %y %m %w %d~' %19620921 1999 -| -| 37 444 1928 13497 -| $ gcal -f/dev/null -Ux -u -#'00000904 %y %B19620921' %19620921 1962 -| -| 37 36

Please do not confound the relative year number %[format]y special text with the age value %B special text (see Age value %[format]B[date] special text). The %y special text counts started years as complete years, while the %B special text does not.


Previous: Other difference values, Up: Replacements without any argument
G.2.3.2 Highlighting %? special texts

The following highlighting %? special texts are respected:

%1
%1 is replaced by the starting highlighting sequence respectively the starting marking character that is used for highlighting the actual day (see Global option --highlighting=text). This attains, that all succeeding text of the line after this special text is displayed in the same way as the highlighted respectively marked actual day. %1 is used together with the %2 special text, which turns off this enabled highlighting sequence respectively produces the ending marking character. If a %1 text is not succeeded by a %2 text on the line, Gcal automatically inserts such a %2 text at the end of the line.

For example:

          Only %1THIS%2 word is highlighted in this line.
          %1This text is highlighted up to%2 here.
          All from %1here up to the end of the line is highlighted.

%2
%2 is replaced by the ending highlighting sequence respectively the ending marking character that is used for highlighting the actual day. This attains, that a possibly active highlighting according to the actual day is turned off respectively an ending marking character is produced. %2 is used together with the %1 special text. The %2 text has no affect if no preceding %1 text was found on the line.
%3
%3 is replaced by the starting highlighting sequence respectively the starting marking character that is used for highlighting a holiday, (see Global option --highlighting=text). This attains, that all succeeding text of the line after this special text is displayed in the same way as the highlighted respectively marked holiday. %3 is used together with the %4 special text, which turns off this enabled highlighting sequence respectively produces the ending marking character. If a %3 text is not succeeded by a %4 text on the line, Gcal automatically inserts such a %4 text at the end of the line.

For example:

          Only %3THIS%4 word is highlighted in this line.
          %3This text is highlighted up to%4 here.
          All from %3here up to the end of the line is highlighted.

%4
%4 is replaced by the ending highlighting sequence respectively the ending marking character that is used for highlighting a holiday. This attains, that a possibly active highlighting according to a holiday is turned off respectively an ending marking character is produced. %4 is used together with the %3 special text. The %4 text has no affect if no preceding %3 text was found on the line.
%5
%5 is replaced by the starting highlighting sequence respectively the starting marking character that is used for highlighting the actual day if a fixed date is on today's date, (see Global option --highlighting=text). This attains, that all succeeding text of the line after this special text is displayed in the same way as the highlighted respectively marked actual day. %5 is used together with the %6 special text, which turns off this enabled highlighting sequence respectively produces the ending marking character. If a %5 text is not succeeded by a %6 text on the line, Gcal automatically inserts such a %6 text at the end of the line.
%6
%6 is replaced by the ending highlighting sequence respectively the ending marking character that is used for highlighting the actual day if a fixed date is on today's date. This attains, that a possibly active highlighting according to the actual day is turned off respectively an ending marking character is produced. %6 is used together with the %5 special text. The %6 text has no affect if no preceding %5 text was found on the line.
%7
%7 is replaced by the starting highlighting sequence respectively the starting marking character that is used for highlighting a holiday if a fixed date is on a legal holiday date, (see Global option --highlighting=text). This attains, that all succeeding text of the line after this special text is displayed in the same way as the highlighted respectively marked holiday. %7 is used together with the %8 special text, which turns off this enabled highlighting sequence respectively produces the ending marking character. If a %7 text is not succeeded by a %8 text on the line, Gcal automatically inserts such a %8 text at the end of the line.
%8
%8 is replaced by the ending highlighting sequence respectively the ending marking character that is used for highlighting a holiday if a fixed date is on a legal holiday date. This attains, that a possibly active highlighting according to a holiday is turned off respectively an ending marking character is produced. %8 is used together with the %7 special text. The %8 text has no affect if no preceding %7 text was found on the line.
%9
%9 is replaced by the starting highlighting sequence respectively the starting marking character that is used for highlighting the actual day if a fixed date is on today's date; otherwise %9 is replaced by the starting highlighting sequence respectively the starting marking character that is used for highlighting a holiday if a fixed date is on a legal holiday date, (see Global option --highlighting=text). This attains, that all succeeding text of the line after this special text is displayed in the same way as the highlighted respectively marked actual day or holiday. %9 is used together with the %0 special text, which turns off this enabled highlighting sequence respectively produces the ending marking character. If a %9 text is not succeeded by a %0 text on the line, Gcal automatically inserts such a %0 text at the end of the line.
%0
%0 is replaced by the ending highlighting sequence respectively the ending marking character that is used for highlighting the actual day if a fixed date is on today's date; otherwise %0 is replaced by the ending highlighting sequence respectively the ending marking character that is used for highlighting a holiday if a fixed date is on a legal holiday date. This attains, that a possibly active highlighting according to today's date or a holiday is turned off respectively an ending marking character is produced. %0 is used together with the %9 special text. The %0 text has no affect if no preceding %9 text was found on the line.


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