Cron Expression Builder

Build cron expressions visually instead of memorising the syntax.

How to use

  1. Choose the minute, hour, day of month, month and day of week from the dropdowns — or leave any field on the wildcard (*) to mean "every".
  2. The cron expression is built live at the bottom with a plain-language explanation, so you can verify it matches what you need.
  3. Copy the five-field expression and paste it into your crontab, CI/CD pipeline, cloud scheduler or any system that accepts standard cron syntax.

About this tool

A cron expression is a five-field string (minute, hour, day-of-month, month, day-of-week) that tells a scheduler when to run a job. Writing one from memory is error-prone — the field order alone trips up experienced engineers.

This builder lets you pick each field visually, shows the resulting expression and translates it into a human-readable sentence so you can double-check before pasting it anywhere.

The expression follows the POSIX cron standard used by crontab, GitHub Actions, AWS EventBridge, Google Cloud Scheduler and most CI/CD systems. Runs entirely in your browser — nothing is sent to any server.

Frequently asked questions

What does the asterisk (*) mean in a cron field?

It means "every". An asterisk in the minute field runs the job every minute; in the month field it means every month. Any field you leave on * applies no restriction for that unit of time.

Does this tool support ranges, lists or step values like */5?

The visual builder covers single values and the wildcard. For advanced syntax (ranges like 1-5, lists like 1,15, or steps like */5) edit the generated expression directly — the format is standard POSIX cron.

What is the difference between 5-field and 6-field cron?

POSIX cron has five fields (minute through day-of-week). Some systems like Quartz or Spring add a sixth field for seconds. This tool generates the standard five-field format, which is what crontab, GitHub Actions and most cloud schedulers expect.

Does my expression leave my browser?

No. The expression is built with JavaScript locally — nothing is transmitted or stored.

Can I test if my cron expression is correct?

The tool shows a plain-language explanation below the expression. Read it carefully — if it says what you expect (e.g. "at minute 30 of hour 2, on Monday"), the expression is correct.

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