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Cron Expression Explainer

Cron Expression
minhourdaymonthweekday
Presets
Explanation

How to use

Type or paste a cron expression into the input field. Pastefix instantly translates it into plain English, breaks down each field (minute, hour, day, month, weekday), and shows the next scheduled execution times. Use the preset buttons to quickly load common schedules. Click "Explain with AI" for a deeper analysis including edge cases and timezone considerations.

What this tool does

Pastefix's Cron Explainer parses standard 5-field cron expressions and converts them into human-readable descriptions. It validates the syntax, explains what each field means with its specific value, and calculates the next upcoming execution times so you can verify the schedule is correct before deploying.

Common use cases

  • Understanding inherited cron schedules in CI/CD pipelines and server configs
  • Building and verifying cron expressions for scheduled jobs (backups, reports, cleanup)
  • Debugging why a cron job runs at unexpected times
  • Translating complex cron syntax (ranges, steps, lists) into plain English for documentation
  • Previewing next execution times before adding a schedule to crontab or Kubernetes CronJobs

Frequently Asked Questions

What cron format is supported?

Pastefix supports the standard 5-field cron format: minute, hour, day of month, month, and day of week. It handles wildcards (*), ranges (1-5), steps (*/5), lists (1,3,5), and combinations of these.

Does it support 6-field or 7-field cron?

Currently Pastefix supports the standard 5-field format used by most cron implementations. Extended formats with seconds or year fields (used by Quartz, Spring, etc.) are not yet supported.

Are the next execution times accurate?

Yes. Pastefix calculates the next runs based on your local system time. Keep in mind that most server cron implementations run in UTC, so adjust accordingly for your deployment timezone.

Is my cron expression sent to a server?

No. Cron parsing, explanation, and next-run calculation all happen in your browser. Only clicking "Explain with AI" sends data for analysis.