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Cron Cookbook

Cron expression validator and explainer

Paste a five-field cron expression to see what each field means, when it runs next, and which platforms accept it as written.

Five fields: minute, hour, day of month, month, day of week. Results update as you type.

your expression · 5 fields
*/159-17**1-5

Every 15 minutes from 09:00 through 17:45, Monday through Friday.

Next 5 runs

Vercel always runs schedules in UTC, and GitHub Actions does unless you set a time zone. Crontab and Kubernetes use the server's time zone.

Field by field

*/15Minute
Every 15th minute: 0, 15, 30, 45
9-17Hour
Every hour from 9 through 17
*Day of month
Every day of the month
*Month
Every month
1-5Day of week
Monday through Friday

Platform check

Whether each scheduler accepts */15 9-17 * * 1-5 as written.

  • crontab

    Accepted

    Runs in the server's local time zone.

  • GitHub Actions

    Accepted

    Runs in UTC unless you add a timezone key. Runs at the start of an hour are the likeliest to be delayed.

  • Kubernetes

    Accepted

    Set spec.timeZone, or the schedule follows the kube-controller-manager's time zone.

  • AWS EventBridge

    Rewrite needed

    EventBridge uses six fields ending in a year, and one of the day fields has to be ?. It numbers weekdays 1-7 starting on Sunday, so the rewrite uses day names. EventBridge Scheduler can run it in any time zone; older scheduled rules use UTC.

    • cron(0/15 9-17 ? * MON-FRI *)

  • Vercel

    Paid plans only

    Runs more than once a day, which fails to deploy on the Hobby plan. Vercel runs cron jobs in UTC.