GNU Micron

Micron is an implementation of the UNIX cron daemon, a program that executes periodically various tasks. It provides a flexible job scheduler, which offers complete control over the execution of the scheduled commands and contains additional organizational features.

Micron is a clean, light-weight cron implementation. It provides a reasonable level of compatibility with the two most widespread cron implementations: Vixie cron (and its derivatives), and Dillon cron. At the same time, it offers a number of new features. Some of them are:

User Group Crontabs
User group crontabs are an experimental feature designed to facilitate maintenance of per-service crontabs, managed by a group of users (e.g. web administrators).
Built-in Variables
A number of built-in variables control interpretation of crontab entries and execution of commands. These can be used to redirect the program output to a particular file or a syslog facility, limit the number of cronjob instances that can run simultaneously, control the semantics of the day field, etc.
Detection of Crontab Modifications
On GNU/Linux systems, micrond uses inotify to track crontab modifications, which means that any change to a crontab is noticed as soon as the crontab file is saved.


Micron was dubbed GNU package on December 13, 2021. While its first release as a GNU package is pending, its previous releases can be downloaded from the following locations: download Micron via HTTPSdownload Micron via HTTP or download Micron via FTP.


Documentation for Micron is online, as is documentation for most GNU software. It can also be accessed by running info micron or man micron, or by looking at /usr/share/doc/micron/, or similar directories on your system. A brief summary is available by running micrond --help.


To report bugs, thoughs, etc. regarding GNU micron, send mail to It is not a mailing list, but an alias distributing mails to the micron maintainer.

Announcements about Micron and most other GNU software are made on the info-gnu mailing list (archives).

Security reports that should not be made immediately public can be sent directly to the maintainer. If there is no response to an urgent issue, you can escalate to the general security mailing list for advice.

Getting involved

Development of Micron, and GNU in general, is a volunteer effort, and you can contribute. For information, please read How to help GNU. If you'd like to get involved, it's a good idea to write to the discussion email (see above).

Development tools
For development sources, issue trackers, and other information, please see the Micron project page at
Trying the latest test release (when available) is always appreciated. Test releases can be found on the Micron alpha server (HTTPSHTTPFTP).
Micron is currently maintained by Sergey Poznyakoff. Please use the mailing lists for contact.


Micron is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 3 of the License, or (at your option) any later version.