Cron Expression Generator
Build, validate, and understand cron expressions with human-readable descriptions and next runs.
Build, validate, and understand cron expressions with human-readable descriptions.
0-59
0-23
1-31
1-12
0-6 (Sun=0)
How do I use Cron Expression Generator?
Click one of the 12 common schedule presets (e.g., 'Every 5 min', 'Weekdays 9am') or type a 5-field cron expression.
Edit any of the 5 fields (`Minute`, `Hour`, `Day of Month`, `Month`, `Day of Week`) using `*`, `/`, `-`, or `,` operators.
Verify the human-readable schedule summary and copy the validated cron string into Crontab, GitHub Actions, or Kubernetes.
What features does Cron Expression Generator offer?
Build & parse standard 5-field cron schedules
Human-readable cron schedule descriptions via cronstrue
Next 5 execution timestamps preview
100% client-side privacy guarantee — zero server tracking
POSIX 5-Field Crontab Syntax & Special Operator Specification
Standard Vixie/POSIX cron expressions consist of 5 whitespace-separated fields evaluated in the server or scheduler's configured timezone.
| Field Position | Field Name | Allowed Numeric Range | Special Operators (* , - /) |
|---|---|---|---|
| Field 1 | Minute | 0 – 59 | */5 = every 5 minutes; 0,30 = at :00 and :30 |
| Field 2 | Hour (24-hr) | 0 – 23 | 0 = midnight (00:00); 9-17 = business hours |
| Field 3 | Day of Month (DOM) | 1 – 31 | 1 = first of month; 1,15 = semi-monthly |
| Field 4 & 5 | Month (1–12) & DOW (0–6) | 1–12 / 0–6 (0=Sun) | 1-5 in DOW = Monday through Friday |
Frequently Asked Questions about Cron Expression Generator
What happens if I specify both Day of Month (field 3) and Day of Week (field 5) in standard cron?
In standard POSIX/Vixie cron, when neither Day of Month nor Day of Week is `*`, they are combined with a logical `OR` (not `AND`)! For example, `0 0 13 * 5` runs on the 13th of every month AND on every Friday.
Why does `*/23` in the Minute field NOT run every 23 minutes evenly across hours?
The step operator `*/23` simply expands to minutes `0, 23, 46` within each hour. After firing at `:46`, the next trigger is at `:00` of the following hour (only 14 minutes later), because cron resets at the top of every hour.
Does `0` or `7` represent Sunday in the Day of Week field?
Standard POSIX and Vixie cron map `0` to Sunday (`0–6` for Sunday–Saturday). While some Linux crontabs also accept `7` for Sunday, `0` is the universally portable value across Linux, GitHub Actions, Kubernetes `CronJob`, and Vercel Cron.
What timezone do GitHub Actions and Vercel Cron schedules use?
Cloud schedulers including GitHub Actions (`on.schedule`), Vercel Cron, and Cloudflare Workers Cron Triggers always evaluate cron expressions in UTC (`+00:00`), whereas a Linux VM `crontab -e` uses the server's local system timezone.
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