Cron Expression Builder & Explainer
Build and explain cron expressions in plain English. Preview the next scheduled runs.
minute (0-59) · hour (0-23) · day-of-month (1-31) · month (1-12) · day-of-week (0-6)
Next 5 runs (your local time)
- 5/30/2026, 9:15:00 AM
- 5/30/2026, 9:30:00 AM
- 5/30/2026, 9:45:00 AM
- 5/30/2026, 10:00:00 AM
- 5/30/2026, 10:15:00 AM
About Cron Expression Builder & Explainer
Paste any cron expression and get a plain-English description of when it runs, plus the next 5 scheduled execution times. Build expressions using the visual field editor (minute, hour, day, month, weekday). Supports standard 5-field cron and extended 6-field (with seconds) syntax. Useful for crontab, GitHub Actions schedules (on.schedule), Kubernetes CronJobs, and cloud function triggers.
All processing happens entirely in your browser using modern web APIs. Nothing is uploaded to our servers — your data stays local and private. Free to use forever.
Common use cases
- Understanding what an unfamiliar cron expression means in plain English
- Building GitHub Actions on.schedule expressions
- Configuring Kubernetes CronJob schedules
- Verifying cloud function trigger schedules (AWS Lambda, GCP Cloud Scheduler)
- Debugging why a scheduled job runs at unexpected times
- Converting between cron fields and human-readable schedules
How it works
The expression is split into 5 fields: minute (0-59), hour (0-23), day of month (1-31), month (1-12), day of week (0-7). Each field supports values, ranges (1-5), lists (1,3,5), step values (*/15), and special strings (@hourly, @daily, @weekly, @monthly). The next-run calculator creates a Date object and iterates forward by one minute until all five field constraints are satisfied.