Cron Expression Builder

A cron expression is a compact string that describes a repeating schedule. It is used by Unix cron, CI pipelines, container orchestrators, and countless job schedulers to decide exactly when a task should run. For example, every five minutes, every night at midnight, or at 9am on weekdays.

A standard cron expression has five space-separated fields, read left to right: minute (0–59), hour (0–23), day of month (1–31), month (1–12), and day of week (0–7, where both 0 and 7 are Sunday). A value of * means "every" for that field.

The */n syntax means "every n units" within a field. So */5 in the minute field runs at minutes 0, 5, 10, 15 … up to 55 (once every five minutes). Likewise */2 in the hour field means every second hour.

Yes. The month field accepts JAN to DEC and the day-of-week field accepts SUN to SAT, in any case and inside ranges and lists, so 0 9 * * MON-FRI works. The shortcuts @yearly, @annually, @monthly, @weekly, @daily, @midnight and @hourly expand to their five-field versions. @reboot runs once when the cron service starts, so it has no schedule to preview.

Each field is expanded into the exact set of values it matches, then the tool walks forward minute by minute from now, in your own local timezone, and lists the next five moments that satisfy every field. When both day-of-month and day-of-week are restricted (neither starts with *), it follows standard cron and treats them as an OR, so 0 9 1 * MON runs on the 1st and on every Monday.

Yes. The Cron Expression Builder is completely free with no login or account required, and everything runs entirely in your browser, so your expressions never leave your device.