Cron Expression Generator

Choose a schedule and get the crontab line for it, described in plain English with the next ten run times worked out in the timezone you pick.

Start from a preset for the common cases, or set the five fields yourself. Already have an expression and want to know what it does? Use the cron expression parser instead.

How it works

A crontab line is five whitespace-separated fields followed by the command to run. In order they are 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 mean Sunday). An asterisk means "every value", so * * * * * runs every minute of every day.

Three operators do most of the work. A comma lists values (0,30). A hyphen gives a range (1-5). A slash gives a step, applied to whatever precedes it — */15 in the minute field means every fifteenth minute, and 0-30/10 means minutes 0, 10, 20 and 30 only.

The trap everyone hits is the relationship between day-of-month and day-of-week. When both are restricted, cron treats them as OR, not AND. 0 0 13 * 5 does not mean "Friday the 13th" — it means every 13th of the month and every Friday. To get a specific weekday, leave day-of-month as *.

The second trap is the step that does not divide evenly. */40 in the minute field fires at minute 0 and minute 40, then the hour rolls over and it fires at 0 again — so the gap is 40 minutes, then 20. Steps only produce an even rhythm when they divide the field's range exactly.

Cron runs in the server's timezone, not yours and not UTC unless the server says so. The preview below lets you choose a timezone so you can see what a schedule will actually do; check the server's own setting before relying on it, especially where daylight saving applies — a job scheduled at 02:30 will be skipped on the spring-forward day and run twice in autumn.

Frequently asked questions