Cron Expression Explainer

Paste a crontab line and read what it actually does. Five fields, plus the @daily style shortcuts. The next run times use your own clock, so if the server runs on UTC, shift them.

Expression

Field by field

Next five runs

* * * * *
| | | | |
| | | | day of week   0-6, or SUN-SAT (7 also means Sunday)
| | | month          1-12, or JAN-DEC
| | day of month     1-31
| hour               0-23
minute               0-59

Written	Means
*	Every value.
5	That one value.
1-5	The range, ends included.
1,15,30	Just those values.
*/15	Every 15th value from the start of the range.
9-17/2	Every second value inside the range.
@daily	Shorthand for 0 0 * * *. Also @hourly, @weekly, @monthly, @yearly.

When both day of month and day of week are set to something other than *, cron runs the job when either matches, not both. So 0 0 13 * 5 is every Friday and every 13th, not Friday the 13th.