Cron Expression

How to use

1. Set each time field (and seconds if your scheduler uses six fields) or start from a preset that matches daily, hourly, or weekly runs.
2. Read the human-readable summary to confirm the next few run times align with your intent and your platform’s timezone.
3. Copy the expression into crontab, Kubernetes `CronJob` spec, Spring `@Scheduled`, or Quartz config, then validate in a staging environment with the same library and zone rules.

FAQ

When should I use five fields versus six?

Classic Unix cron uses five fields from minute through weekday. Schedulers such as Quartz or some cloud products add a leading seconds field—always match the field count and order your runtime documents.

Why did my job run at a different local time after daylight saving?

Cron is evaluated in the server or job runner’s timezone; DST shifts wall-clock times. Pin critical schedules to UTC in config when possible, or re-check offset after clocks change.

Can one expression cover “last Friday of the month”?

Standard cron cannot express arbitrary “nth weekday of month” in one token; you often need application logic or a richer scheduler. This tool still helps with the repeating parts of the schedule you can express in cron.