Answer the receiver, since DateTime objects store themselves
in Local time
asUTC
Convert the receiver to UTC time, and answer a new DateTime object.
offset
Answer the receiver's offset from UTC to local time (e.g. +3600 seconds
for Central Europe Time, -3600*6 seconds for Eastern Standard Time).
The offset is expressed as a Duration
offset: anOffset
Answer a copy of the receiver with the offset from UTC to local time
changed to anOffset (a Duration).
timeZoneAbbreviation
Answer an abbreviated indication of the receiver's offset, expressed
as `shhmm', where `hh' is the number of hours and `mm' is the number
of minutes between UTC and local time, and `s' can be `+' for the
Eastern hemisphere and `-' for the Western hemisphere.
timeZoneName
Answer the time zone name for the receiver (currently, it is
simply `GMT +xxxx', where `xxxx' is the receiver's
#timeZoneAbbreviation).