Guide: validate cron expressions and next runs
Schedulers (Linux cron, node-cron, GitHub Actions, CloudWatch) use minute, hour, day-of-month, month, and day-of-week fields — sometimes with seconds or Quartz variants. One wrong comma or `*` fires jobs off-schedule.
The tool parses expressions in-browser and lists upcoming run times without uploading your schedule. Great for backup windows, nightly reports, or cache purge jobs before infra commits.
Use when migrating legacy crons, writing runbooks, or explaining why a job hits 03:00 UTC. Cross-check timezones with the timestamp converter if output is UTC.
Step by step
- Enter the cron expression — Paste five or six fields per your engine (e.g. `0 9 * * 1-5` for weekdays at 09:00).
- Review syntax per field — Ranges (`1-5`), lists (`1,15`), and steps (`*/10`) differ by position — errors show with a clear message.
- Inspect upcoming runs — The next-run list confirms weekends, month boundaries, and expected local time.
- Move to your environment — Copy into crontab, Terraform, or workflow YAML — test in staging with an explicit timezone.