Crontab format ============== Mcron is not strictly POSIX compatible, because of a small change in the matching day ruleset. The difference is highlighted. The five first fields shall be integer patterns that specify the following: 1. Minute [0,59] 2. Hour [0,23] 3. Day of the month [1,31] 4. Month of the year [1,12] 5. Day of the week ([0,6] with 0=Sunday) Each of these patterns can be either an (meaning all valid values), an element, or a list of elements separated by characters. An element shall be either a number or two numbers separated by a (meaning an inclusive range). The specification of days can be made by two fields (day of the month and day of the week). If month, day of month, and day of week are all characters, every day shall be matched. If either the month or day of month is specified as an element or list, but the day of week is an , the month and day of month fields shall specify the days that match. If both month and day of month are specified as an , but day of week is an element or list, then only the specified days of the week match. Finally, if either the month or day of month is specified as an element or list, and the day of week is also specified as an element or list, **then any day matching all the month, day of month, and the day of week, shall be matched**. The sixth field of a line in a crontab entry is a string that shall be executed by sh at the specified times. A character in this field shall be translated to a . Any character preceded by a (including the '%' ) shall cause that character to be treated literally. Only the first line (up to a '%' or end-of-line) of the command field shall be executed by the command interpreter. The other lines shall be made available to the command as standard input. Blank lines and those whose first non- is '#' shall be ignored. Example: -------- .. code-block:: crontab # # [0,59] [0,23] [1,31] [1,12] [0,6] with 0=Sunday 0,15,30,45 8-18 * * 1,5 notify-send "raise your eyes and look something far" 30 17 * * 1,5 send-email%To: my@boss.com%%Hey,%%Leaving the office for today.% The previous entry would trigger every quarter hour, on work days, from 8 AM to 6 PM.