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Cron Builder & Explainer

Write or build a five-field cron schedule, read it in plain English, and see its next five run times in UTC. Nothing is sent or stored.

Cron expression (five fields, or an alias such as @daily)

Enter an expression.

Builder

Pick a value for each field. The choices write the expression above. Typing in the expression box does not change the choices.

Minute (0-59) Hour (0-23, UTC) Day of month (1-31) Month (1-12) Day of week (0-7, Sunday is 0 or 7)

Next five run times

Expression read as-

Day rule-

Time zone of the timesUTC

Every time shown is UTC. A server or scheduler that reads this expression in its own time zone runs it at a different clock time, unless you convert the hour yourself. Daylight saving is not applied.

How it works

Fields. The expression has five fields in this order: minute (0-59), hour (0-23), day of month (1-31), month (1-12 or JAN to DEC) and day of week (0-7 or SUN to SAT, where 0 and 7 are both Sunday). Each field accepts a single value, a list such as 1,15, a range such as 9-17, or a step such as */15 or 9-17/4. The aliases @hourly, @daily, @weekly, @monthly and @yearly stand for the usual five-field forms.

Day rule. When both day of month and day of week are restricted, a day matches if either one matches. This is the standard cron rule, so 0 12 13 * 5 runs on the 13th and on every Friday. When one of them is *, only the other applies. A field that starts with * (for example */2) is treated as unrestricted, so both fields must match.

Times are UTC. The next runs are calculated in Coordinated Universal Time with no local time zone and no daylight saving. The next run is the first matching minute after the current time. An expression that never matches, such as 31 February, reports "No run found".