Cron Expression Builder
Build, test, and explain cron schedules with next-run preview
* any value, value list (e.g. 1,3,5)- inclusive range (e.g. 1-5)/ step (e.g. */15 = every 15)@yearly @monthly @weekly @daily @hourly shortcutsHow to use
- Type a cron expression or pick a preset
- Read the plain-English description
- Check the next 10 execution times
- Copy the expression to your scheduler
Use cases
- Scheduling jobs
- Kubernetes CronJobs
- GitHub Actions
- Crontab setup
About the Cron Expression Builder
A cron expression is a 5-field schedule descriptor used by Unix cron, Kubernetes CronJobs, GitHub Actions, Vercel, AWS EventBridge, and nearly every scheduler. The syntax is compact but easy to get wrong — this builder validates it, describes it in English, and shows you the next 10 times it will fire so you can sanity-check before deploying.
Features
- Per-field breakdown of minute / hour / day-of-month / month / day-of-week
- Plain-English description generated from any expression
- Next 10 execution times with 'minutes from now' offset
- 12 common-pattern presets — click to apply
- Supports shortcuts: @yearly @monthly @weekly @daily @hourly
- Month and day names (Jan/Mon) honored alongside numeric values
How it works
- Type or click a preset to load a cron expression.
- Read the per-field breakdown and the plain-English description.
- Review the next 10 execution times to confirm the schedule matches your intent.
- Copy the expression into your crontab, CI config, or scheduler.
Frequently asked questions
What cron dialect does this use?
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Standard 5-field POSIX cron (minute hour day-of-month month day-of-week). No seconds field, no Jenkins-style H, no AWS Lambda's 6-field dialect.
How does it handle the day-of-month + day-of-week combo?
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Per the POSIX spec: when both fields are restricted, either match runs the job. When one is * it's ignored.
Are day/month names supported?
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Yes. Both numeric (0-6 for Sun-Sat) and name (sun, mon, tue…) forms work; case-insensitive.
Does it show UTC or local time?
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The 'Next executions' list renders in your browser's local time zone. If you need UTC, subtract your offset — or paste a few results into our Time Zone Converter.
Why did my expression fail to parse?
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The error message names the specific field or token. Most common cause: a 6-field expression (common on Quartz / Spring). Remove the seconds field.