Cron Expression Parser
Type any cron expression to see a plain-English description and the next 10 scheduled runs in UTC.
Cron expression
Presets
Next 10 runs (UTC)
Times are in UTC. Schedules typically run in the timezone of the host (or UTC for cloud schedulers).
About this tool
A cron expression parser that validates the syntax, explains the schedule in plain English, and shows you the next 10 runs in UTC. Perfect for scheduling cloud functions, background jobs, and crontab entries you can't afford to get wrong.
How to use it
Quick steps to get the most out of this utility.
- 1
Type or pick a preset
Start with a built-in preset and adapt, or type from scratch.
- 2
Read the description
The plain-English summary tells you what your expression actually does.
- 3
Verify next runs
The 10 upcoming run timestamps make scheduling bugs obvious before deploy.
- 4
Copy and paste
Drop into crontab, GitHub Actions, AWS EventBridge, or Cloud Scheduler.
Cron field reference
| Field | Range | Special chars |
|---|---|---|
| Minute | 0-59 | * , - / |
| Hour | 0-23 | * , - / |
| Day of month | 1-31 | * , - / |
| Month | 1-12 | * , - / |
| Day of week | 0-6 (Sun=0) | * , - / |
Common gotchas
- Day-of-month + day-of-week: if both are non-*, most implementations OR them, not AND.
- Timezones: cloud schedulers usually default to UTC; system cron uses local TZ.
- Steps don't straddle:
*/15on the hour field means 0, 15, 30, 45 — not arbitrary 15-minute intervals across hour boundaries.
Frequently asked questions
What's the cron expression format?+
Five space-separated fields: minute (0-59), hour (0-23), day of month (1-31), month (1-12), day of week (0-6, Sunday=0). Use * for "any", */N for "every N", and ranges like 1-5.
Why does my cron job run more often than expected?+
When both day-of-month and day-of-week are specified (neither is *), most cron implementations run when EITHER matches. So "0 0 1 * 1" fires on the 1st of every month AND every Monday.
How do I run something every 90 minutes?+
You can't directly — cron only supports intra-hour or intra-day patterns, not arbitrary intervals that don't divide cleanly into 60. The workaround is two entries: "0 0,3,6,9,12,15,18,21 * * *" for every 3 hours starting midnight, plus "30 1,4,7,10,13,16,19,22 * * *" for the 90-min offsets.
What timezone do cron jobs run in?+
Traditional Unix cron uses the system timezone. Cloud schedulers (AWS EventBridge, GCP Cloud Scheduler, Vercel Cron) typically default to UTC. Always check your scheduler's docs and explicitly set TZ if needed.
Keep exploring
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