Crontab Cheatsheet

* * * * *     user    cmd

Here is how positions 1-5 are layed out:

1 Minute 0-59
2 Hour 0-23 (0 = midnight)
3 Day 1-31
4 Month 1-12
5 Weekday 0-6 (0 = Sunday)

One can use the English abbreviated day of the week in place of the numbers

0=Sun
1=Mon
2=Tue
3=Wed
4=Thu
5=Fri
6=Sat

 These special time specification “nicknames” are supported, which replace the 5 initial time and date fields, and are prefixed by the ‘@’ character:

@reboot : Run once after reboot.

@yearly : Run once a year, ie. “0 0 1 1 *”.

@annually : Run once a year, ie. “0 0 1 1 *”.

@monthly : Run once a month, ie. “0 0 1 * *”.

@weekly : Run once a week, ie. “0 0 * * 0”.

@daily : Run once a day, ie. “0 0 * * *”.

@hourly : Run once an hour, ie. “0 * * * *”.

 

If you wish to diasble the email (and not output to a log file) then, at the end of each of the cron job lines you wish to not be notified on, place the command:

>/dev/null 2>&1