In plain English, with the next ten run times — so you find out it fires every minute before you deploy it.
Five fields: minute, hour, day of month, month, day of week. Supports *, 5, 1-5, */15, 1,3,5, MON, JAN.
This runs
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Next ten runs ·
The day-of-month / day-of-week trap. When both fields are
restricted, cron treats them as OR, not AND. 0 0 13 * FRI
does not mean "Friday the 13th" — it means "every 13th and every Friday". This is
the single most common cron bug, it is in the POSIX specification, and the run list above
applies the same rule so you can see it happen.