Cron Reader — translate any cron expression to plain English

• English description — derived from the same cronstrue library used by major schedulers. Example: `0 0 L * *` becomes “At 00:00, on the last day of the month”.
• Calendar of next runs — the next 30+ scheduled fires plotted in a real month view. Spot weekend runs, holiday gaps, and end-of-month anomalies instantly.
• Field-by-field decode — each field shows what it accepts and what your value resolves to.
• Validation — invalid fields highlight in red with the parser error in plain English.
• Shareable link — copy a URL with the cron pre-filled to share the decoded view with your team.

• * * * * * — Every minute.
• */5 * * * * — Every 5 minutes.
• */15 * * * * — Every 15 minutes.
• 0 * * * * — Every hour, on the hour.
• 0 0 * * * — Every day at midnight.
• 0 9 * * 1-5 — Every weekday at 09:00.
• 0 0 1 * * — On the 1st of every month at midnight.
• 0 0 L * * — On the last day of every month at midnight (Quartz / AWS / robfig).
• 0 0 1,15 * * — On the 1st and 15th of every month at midnight.
• 30 8,17 * * * — At 08:30 and 17:30 every day.

See more in the full cron index or click any of these examples to view them on the calendar.

The cron reader takes an existing expression and explains it. The cron builder goes the other way — you pick the cadence, day, hour, and minute from inputs and CronTool composes the cron string. Use the reader when you have a string from a colleague, a docs page, or a legacy job; use the builder when you're writing one from scratch.

For decoding multiple cron expressions at once (a whole crontab file), the multi-cron visualizer lets you upload crontab -l output and see every schedule on the same calendar.

The reader accepts the standard Unix 5-field syntax plus extended dialects:

• Unix crontab (* * * * *)
• AWS EventBridge / Lambda Scheduled (* * * * ? *)
• Vercel cron jobs (5 fields, UTC)
• Quartz Scheduler (6-7 fields with seconds and year)
• robfig/cron, node-cron, rufus-scheduler, ncrontab, dragonmantank/cron-expression

Toggle the extended-cron switch at the top of the page to enable seconds, year and the ? / L / W / # modifiers.