Cron Expression Builder — Parse & Predict Next Runs Online
Parse cron expressions to plain English + predict the next 7 runs. Supports 5-field standard (minute hour day-of-month month day-of-week) + 10 common presets. For Linux cron, GitHub Actions schedule, Kubernetes CronJob.
Every 15 minutes, every hour, every day
- 1. 6/26/2026, 7:30:00 AM
- 2. 6/26/2026, 7:45:00 AM
- 3. 6/26/2026, 8:00:00 AM
- 4. 6/26/2026, 8:15:00 AM
- 5. 6/26/2026, 8:30:00 AM
- 6. 6/26/2026, 8:45:00 AM
- 7. 6/26/2026, 9:00:00 AM
Common presets
Why use this tool
Paste '*/15 9-17 * * 1-5' → tool reads it as 'Every 15 minutes, 9 AM to 5 PM, Monday to Friday'.
Avoid misreading a schedule. The tool computes 7 upcoming runs in your local timezone.
Every 5 minutes, hourly, weekdays 9-5, weekends — click to load instantly.
How to use
- 1Paste cron expression (e.g. '*/15 * * * *') or click a preset.
- 2Tool shows real-time explanation + 7 next runs.
- 3Edit each field (minute / hour / day / month / weekday) to see the schedule update.
- 4Copy the expression once happy → paste into crontab / CI YAML.
Cron Expression — Done right
Cron is the schedule standard on Linux since the 70s, still everywhere: /etc/crontab, GitHub Actions on.schedule, Kubernetes CronJob, AWS EventBridge, BullMQ. 5 fields: minute (0-59) hour (0-23) day-of-month (1-31) month (1-12) day-of-week (0-6, 0=Sunday).
Syntax is bug-prone: '*/5 * * * *' (every 5 min) differs from '0 */5 * * *' (every 5 HOURS). '0 9 * * 1-5' (M-F 9 AM) differs from '0 9 1-5 * *' (days 1-5 each month at 9 AM). This tool uses cronstrue + cron-parser for accurate parsing.
Timezone note: Linux cron uses system TZ. GitHub Actions runs UTC. Kubernetes CronJob has spec.timeZone (1.27+). Always document timezone for production cron.
- ✓5-field standard cron
- ✓VI + EN locale
- ✓Predict next 7 runs
- ✓10 common presets
- ✓Realtime edit
- ✓100% client-side
FAQ
Support 6-field cron (seconds)?
6-field cron (Quartz, BullMQ second-precision) not supported in v1. Coming Phase 2.
Why does the UTC time differ from my machine?
Tool predicts using your local timezone. Production cron may run in a different TZ — check TZ env / CronJob.spec.timeZone.
Cron 'L', 'W', '#' (Quartz extensions)?
Quartz extensions not supported in v1. Quartz is for Java Spring schedulers.