Cron Expression Parser

Turn cryptic crontab lines into plain English — and see exactly when they will fire next.

About this tool

*/15 9-17 * * MON-FRI is obvious once someone translates it: “every 15 minutes between 09:00 and 17:59 on weekdays”. This parser validates all five standard cron fields (minute, hour, day-of-month, month, day-of-week), supports ranges, steps, lists, question marks and month/day names, describes the schedule in words, and computes the next five runs from your local clock.

How to use it

  1. Type or paste the cron expression, or click Sample.
  2. Click Parse & explain — invalid fields are reported precisely.
  3. Check the upcoming run times to confirm the schedule means what you intended.

Good to know

  • Standard 5-field crontab syntax only — the optional seconds field of Quartz is not supported.
  • When both day-of-month and day-of-week are restricted, standard cron ORs them; the parser follows that rule and the next-run preview makes it visible.
  • Next runs are computed for your local time zone, like most cron daemons.