Cron Expression Builder

A cron expression is a 5-field string (minute, hour, day-of-month, month, day-of-week) that defines a recurring schedule. For example, '0 9 * * 1' runs every Monday at 9:00 AM. Cron is used in Linux, CI/CD pipelines, cloud functions, GitHub Actions, and task schedulers.

Use '*/5 * * * *'. The '*/5' in the minute field means 'every 5th minute starting from 0'. Similarly, '*/10' runs every 10 minutes and '*/30' every 30 minutes. You can use the step syntax (*/n) in any field.

Use '0 9 * * 1-5' to run at 9 AM Monday through Friday. The day-of-week field '1-5' means Mon(1) through Fri(5). For weekends only, use '0,6' or 'SAT,SUN' in the day-of-week field.

An asterisk (*) means 'every possible value' for that field. '* * * * *' runs every minute of every hour of every day. You can also use ranges (1-5), lists (1,3,5), and step values (*/15).

Both tools help you build cron expressions. The cron builder focuses on interactive construction — choose from presets and see the plain-English description. The cron validator helps you verify an existing expression. Use whichever fits your workflow.