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Cron Explainer

Cron Explainer — runs in your browser. Inputs are not stored.

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Cron expression explainer

Enter values, then press Calculate.

How to use

  1. Paste minute hour day month weekday order into 5-field Cron. The default example is */15 9-18 * * 1-5.
  2. Press Explain for a one-line summary and per-field notes. The default is also explained on page load.
  3. Match ranges: minute (0-59), hour (0-23), day (1-31), month (1-12), weekday (0-6, 0=Sunday).
  4. For 6-field cron with seconds, drop the leading seconds field and keep five. @daily macros need a numeric pattern.
  5. Next-run time is not calculated. To build an expression, use the Cron generator tool.

Key concepts

This cron expression explainer turns 5-field expressions from Linux crontab, CI schedules, and Kubernetes CronJobs into a plain-language summary. * is every value, */n is every n, a-b is a range, commas are lists. Weekday 1-5 is summarized as weekdays. It is an explainer that unpacks operating schedule expressions so you can confirm what minute, hour, day, month, and weekday mean. Next-run time is not calculated. Reading weekday and hour in words before a production deploy reduces mistaking daily, weekdays, and hourly. Check next-run time separately.

Seconds fields, year fields, and Quartz 7 fields are not supported. It explains meaning only and does not compute time zone or next run. Parsing runs only in the browser. There is no seconds field, year field, @hourly macro, or next-run calculation. Read meaning here and generate elsewhere. Only 5 fields are accepted, so Quartz expressions with seconds must drop the first field. Expand macros such as @daily into numbers.

Example

Explaining the default */15 9-18 * * 1-5 shows every 15 minutes · 9:00–18:00 · every day · every month · weekdays. 0 9 * * 1 is 9:00 sharp, every day of month, Monday. Four fields produce a message that 5 fields are required. 0 0 1 * * is 00:00 on the 1st of every month. */5 * * * * is every 5 minutes. Six fields: drop seconds. 30 4 * * 0 is Sunday 4:30. Four fields produce an error notice.

Related: Cron generator

Frequently asked questions

Are 6-field cron expressions (with seconds) explained?

Not supported. Remove the leading seconds field. Leaving 6-field seconds in place causes a field-count error.

Do cron macros such as @daily work?

Only number, *, /, -, and comma patterns are explained. Expand @daily to numeric fields such as 0 0 * * *.

Is cron weekday 0 Sunday?

Yes, Sunday. Some systems also use 7 as Sunday. This screen uses 0–6. Do not confuse it with systems where Monday is 1. Also check your system docs for whether weekday 0 is Sunday.

Can I also generate a cron expression?

Explain only. Use the Cron generator tool to build one.

Does it calculate the next cron run time?

No; it only explains meaning. Time zone and daylight saving are not calculated.

Why is weekday 1-5 shown as weekdays?

Monday–Friday is summarized as weekdays. 0 and 6 are shown as weekend. 1-5 is weekdays; 0,6 is weekend.

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Last reviewed: 2026-09-04