Home/Cron expression parser

Five-field Unix cron

See when the schedule will actually run.

Validate the expression, inspect every field, and preview ten exact instants in the time zone your scheduler is meant to use.

Input

Cron expression

Example: 0 9 * * 1-5 runs at 09:00 Monday through Friday.

Result

Schedule preview

Each run is shown as a separate card on this screen.

#Selected zoneUTC instant

How a Unix cron expression is read

A conventional crontab schedule has five fields in this order: minute, hour, day of month, month, and day of week. An asterisk accepts every value. A comma selects a list, a hyphen selects a range, and a slash applies a step.

15Minute
2Hour
*Day of month
*Month
1-5Day of week
The expression 15 2 * * 1-5 selects 02:15 from Monday through Friday.

The day-of-month and day-of-week trap

In common Unix cron implementations, when both fields are restricted, a run can match either field. For example, 0 9 1 * 1 means 09:00 on the first day of a month and on Mondays. It does not mean only Mondays that are also the first.

Confirm the runtime. Linux crontab, Kubernetes, GitHub Actions, AWS EventBridge, Quartz, and framework schedulers do not all share one grammar or one time-zone rule. This page models five-field Unix cron only.

Example: weekday maintenance

For 15 2 * * 1-5, minute is 15, hour is 2, both date fields allow every value except weekdays, and the job is eligible at 02:15 from Monday through Friday. The UTC instant changes across daylight-saving transitions if the scheduler follows a regional time zone.

What this preview does not prove

The preview searches up to two years ahead. It does not execute a command, monitor a job, or prove that a particular platform accepts the expression. Always check the scheduler documentation and its configured time zone before deployment.

Common questions

Does this support Quartz cron expressions?

No. Quartz normally adds a seconds field and may add a year field, plus tokens that do not exist in ordinary crontab syntax.

Why are the UTC times different after a DST date?

A regional wall-clock time can keep the same hour while its UTC offset changes. That is why each preview row shows both the selected zone and the exact UTC instant.