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Cron Expression Parser

Explain a 5-field cron expression and show when it next runs.Developer Tools

Cron Expression Parser

Decode a 5-field cron expression into a human description and see when it next fires.

minute hour day-of-month month day-of-week — numbers, ranges, steps and lists.

Minute: 0, 15, 30, 45 · Hour: 9, 10, 11, 12, 13, 14, 15, 16, 17 · Day of month: every day · Month: every month · Day of week: Monday, Tuesday, Wednesday, Thursday, Friday
Next 5 runs
  1. #11/1/2026, 9:00:00 AM
  2. #21/1/2026, 9:15:00 AM
  3. #31/1/2026, 9:30:00 AM
  4. #41/1/2026, 9:45:00 AM
  5. #51/1/2026, 10:00:00 AM

About this tool

Cron expressions are write-only until you meet one in production. Paste an expression to see which minute, hour, day and month each field selects, plus the next five times it actually fires from now or from the start of the year.

How to use the Cron Parser tool

  1. Paste the expression. Five fields: minute, hour, day-of-month, month, day-of-week. Ranges, steps and lists all work.
  2. Read the description. Each field's meaning is spelled out, including the crontab OR rule when both day fields are restricted.
  3. Preview the schedule. The next five run times are computed and shown in your local timezone.

Supported formats

Input

  • A 5-field cron expression

Output

  • Plain-language field description
  • The next five run times

Inputs are validated before anything is processed. Invalid values and unsupported files are rejected with a clear error instead of failing silently.

Frequently asked questions

Does it support @daily or 6-field expressions?

No. Only the classic 5-field POSIX-style syntax.

What happens when both day fields are set?

Standard crontab behaviour applies: the job runs when either the day-of-month or the day-of-week matches.

Which timezone are the run times in?

Your browser's local timezone, so the preview matches what you would see in local logs.

Is 7 accepted for Sunday?

Yes, and it is normalised to 0 like every crontab implementation.

Privacy

Everything you enter stays in this browser tab. There is no upload endpoint for tool inputs, no account, and no server-side copy of your text or files. Results are produced locally and disappear when you close the page.

No account is required and no file is ever uploaded. See the privacy policy for details about analytics and the limited data this site stores.

Known limitations

  • Only 5-field expressions; @reboot-style shortcuts and seconds fields are not supported.
  • Yearly, monthly and other named macros are not accepted.
  • Daylight-saving gaps can shift the next local run by an hour, matching real cron behaviour.

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