Cron Expression Parser
Parse five-field Unix cron expressions locally in your browser, expand field meanings, and preview upcoming run times.
Paste a cron expression such as */15 9-17 * * MON-FRI to inspect minute, hour, day-of-month, month, and weekday fields. Preview upcoming runs in your browser local timezone or UTC without creating a job or contacting a server.
Browser-local processing
Cron Expression Parser
How to use
Finish in three steps
- 01
Enter a five-field Unix cron expression in the order minute hour day-of-month month day-of-week.
- 02
Choose browser local time or UTC, and optionally set the preview start and row count.
- 03
Click "Parse Cron" to see expanded fields, dialect notes, and upcoming run times.
- 04
Use the result as a static check, then compare seconds, timezone, and special syntax with the target scheduler documentation.
Supported cron dialect
The tool focuses on five-field Unix cron: minute, hour, day of month, month, and weekday. It supports numbers, ranges, lists, steps, English month and weekday aliases, and common macros such as @hourly, @daily, @weekly, @monthly, and @yearly.
Timezone and preview limits
Preview can run in browser local time or UTC and shows up to 12 future times strictly after the chosen starting minute. The search stops after 366 days; 0 9 1 1 * started at 2026-01-01 09:00 UTC therefore returns 2027-01-01 09:00 UTC, not the starting instant.
Not a replacement for the scheduler
Platforms may use Quartz, Kubernetes, GitHub Actions, or cloud-provider extensions. Before production changes, compare the expression with the target scheduler documentation and actual execution logs.
FAQ
About this tool
Does this tool support seconds?
No. It supports five-field Unix cron only, not Quartz-style seconds, year fields, or ? placeholders.
How are weekday 0 and 7 handled?
Both are treated as Sunday. English aliases such as MON-FRI and JAN-DEC are also supported.
What happens when both day-of-month and day-of-week are restricted?
The preview uses common Unix/Vixie cron OR semantics: either the day-of-month or the weekday may match. Always confirm with your target platform.
Is the expression sent to a server?
No. Parsing and preview stay in the browser. The tool does not create jobs or call external APIs.
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