Cron Expression Parser
Paste a cron expression to validate it, read it in plain language and list the next 10 run times in any time zone. Supports seconds fields and @daily macros.
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5 fields, 6 fields with seconds, or a macro such as @daily
What is Cron Expression Parser?
Paste any cron expression to check that it is valid, see what it means in plain language, view each field separately and list the next 10 run times in the time zone you choose. It accepts 5-field crontab syntax, 6-field expressions with seconds first, names like MON-FRI and macros such as @daily.
How to use Cron Expression Parser
- Type or paste the expression into Cron expression.
- Read the Meaning and the field breakdown below it.
- Choose the Time zone your scheduler uses.
- Check the Next run times list.
Example
*/15 9-17 * * 1-5
Every 15 minutes, between 09:00 AM and 05:59 PM, Monday through Friday
When to use Cron Expression Parser
Use it to understand a cron line you found in a crontab, CI config or Kubernetes manifest, or to double-check a schedule before deploying. It does not run anything; it only explains and previews. To build a new expression by clicking, use the Cron Expression Generator.
How Cron Expression Parser works
The tool first checks the number of fields (5 or 6, or a supported macro), then parses the expression with cron-parser, which validates every value against its range (minutes 0-59, hours 0-23, etc.) and supports lists, ranges, steps, month/day names and the L and # modifiers. Next runs are calculated from the current moment in the selected IANA time zone and shown with your browser's date format. The description comes from cronstrue, localized where a translation exists.
Common Use Cases
- Reviewing schedules in a crontab or Kubernetes CronJob
- Checking when a GitHub Actions schedule will fire in UTC
- Debugging why a job ran at an unexpected time
- Validating expressions before adding them to a scheduler
FAQs
Why is my expression invalid?
The most common causes are a wrong number of fields (crontab needs 5) or a value outside its range, such as minute 60 or hour 24.
Does it support seconds?
Yes. With 6 fields the first one is interpreted as seconds, as in Quartz-style and Node schedulers.
Are the next run times exact?
Yes, for the selected time zone, including daylight-saving transitions. Your scheduler must of course use the same time zone.