Cron cheatsheet

# Cron cheatsheet
#
# * * * * * command to be executed
# - - - - -
# | | | | |
# | | | | +- - - - day of week (0 - 6) (Sunday=0)
# | | | +- - - - - month (1 - 12)
# | | +- - - - - - day of month (1 - 31)
# | +- - - - - - - hour (0 - 23)
# +- - - - - - - - minute (0 - 59)

# Alarm clock set to 6:30AM
# 30 6 * * * /home/nano/alarm

For several fields, you may denote subdivision by using the forward-slash (/) character. To execute a job every 5 minutes, */5 in the minutes field would specify this condition.

Spans may be indicated using the dash (-) character. To execute a job Monday through Friday, MON-FRI should be used in the day-of-week field.

Multiple values may be separated using the comma (,) character. The specification of 1,15 in the day-of-month field would result in the job firing on the 1st and 15th of each month.

Either day-of-month or day-of-week must be specified using the ? character, since specifying both is contradictory.