Chances are, you have used CRON syntax in the past. If you’re anything like me, you probably used AI to generate the CRON expression that matched your needs.

Sometimes however, I like using my own brain for a change. In that spirit, I did a little refresher on the (traditional Unix) CRON syntax. I’d like to share it with you.

*	*	*	*	*
Minute	Hour	Day (month)	Month	Day (week)
				0=7=Sunday

* = any value

, = value list separator. E.g. 1,5 = the values 1 and 5.

– = range of values. E.g. 2-6 = the values 2, 3, 4, 5 and 6.

/ = step values. E.g. */30 * * * * = every 30 minutes.

Example:

*/30	8-20	*	*	1-4
Every 30 minutes	From 8:00 till 20:30	Every day of the month	Every month	Monday till thursday