PatternCron
Every 15 minutes
The step-value schedule for polling, health checks and sync jobs: */15 fires on the quarter hour, around the clock.
Last updated
In plain English
- Fires at :00, :15, :30 and :45
- 96 runs per day
Why it’s written this way
*/15 in the minute field means "every value divisible by 15": minutes 0, 15, 30 and 45 of every hour. The other four stars leave hour, day and month unconstrained.
Steps divide the field's own range, which is why they read so cleanly for 5, 10, 15, 20 and 30 — the divisors of 60.
Edge cases to know
- →*/17 does NOT mean "every 17 minutes" — it means minutes 0, 17, 34, 51, then a 9-minute gap to the next hour's 0. Steps reset at the field boundary.
- →All instances of a fleet fire at the same instant; add a random sleep (or use systemd timers' RandomizedDelaySec) if a thundering herd matters.
- →For sub-minute schedules cron is the wrong tool — use a loop or a timer service.