Cron Expression Generator

Build and read cron expressions without guessing

Cron syntax is five terse fields — minute, hour, day of month, month, day of week — and one wrong asterisk quietly reschedules your job. This tool works both ways: start from a preset or edit any field to build an expression, or paste one you already have to see exactly what it does. It reads the standard Unix crontab format, plus 6-field expressions with seconds and shortcuts like @daily.

Every change updates a plain-English description and a list of the next several run times, so you can confirm the schedule matches your intent before you commit it to a server. Switch between your local timezone and UTC, choose a 12- or 24-hour clock, and copy the finished expression with one click.

Because it runs entirely in your browser, nothing you type is sent anywhere — handy when the expression names an internal job. One honest caveat: the next-run times use your computer's clock and the classic Vixie/Unix cron interpretation. Some schedulers (Quartz, AWS EventBridge, Kubernetes CronJobs) tweak the field rules or the day-of-month vs day-of-week logic, so treat the preview as the standard-cron answer and check your platform's docs for exotic syntax.

• Server automation: Schedule a backup, log rotation, or cleanup script and confirm it fires at 2 AM on weekdays, not every minute.
• Decode an inherited crontab: Paste a cryptic */15 9-17 * * 1-5 from someone else's config and get "Every 15 minutes, between 09:00 and 17:00, Monday through Friday."
• CI/CD pipelines: Write the schedule for a GitHub Actions, GitLab, or Jenkins job and verify the next runs land where you expect.
• Recurring reports and emails: Set a monthly-on-the-1st or quarterly cadence and see the actual dates it will trigger.
• Learning cron: Toggle each field and watch the English and the run times change — the fastest way to build an intuition for steps, ranges, and lists.
• Timezone sanity check: Compare a schedule in your local time against UTC before deploying to a server that runs in a different zone.

Privacy: This tool runs entirely in your browser. Your cron expressions are parsed and previewed on your own device — nothing is uploaded, logged, or sent to any server.