Cron Generator
Build a cron expression from five visual fields and preview the next five run times.
Minute
Hour
Day of month
Month
Day of week
Reads as： —
Next 5 runs (browser local time)
No matching run within the next two years.
Values accept numbers or three-letter names (jan, mon). When day-of-month and day-of-week are both restricted, a day matches if either one matches (Vixie cron).
How to use it
- Work through the five rows top to bottom: minute, hour, day of month, month, day of week.
- For each row pick a mode: Every (
*), Pick values (0,15,30,45), Range (9-17) or Every N (*/15). - Values accept plain numbers or three-letter names such as
janfor January andmonfor Monday. - Read the human sentence under the expression to confirm the schedule says what you meant.
- Check Next 5 runs against the calendar, then copy the five-field expression into crontab, a CI schedule or a job runner.
Common use cases
- Writing a backup schedule — nightly at 02:30 becomes
30 2 * * *; verify it in the run preview before you save the crontab entry. - Business-hours polling —
*/15 9-17 * * 1-5runs every fifteen minutes between 09:00 and 17:00 on weekdays only. - Monthly reporting — pick day of month 1 with hour 8 and confirm the next five dates land on the first of each month.
- Teaching cron syntax — switching a field between modes shows immediately how the expression and the description change.
- Sanity-checking a migration — rebuild an existing schedule here and compare the generated run times with what the old host produced.
Why it stays private
Every field, expression and run-time calculation is computed in your browser. No schedule, host name or job detail is sent anywhere, so you can describe infrastructure timings freely.
FAQ
Q: Which cron dialect does the preview follow? A: Standard five-field Vixie cron. When day of month and day of week are both restricted, a day matches if either one matches, which is the behavior most Linux hosts implement.
Q: Why are the run times in my local time zone? A: The preview uses the time zone of your browser. Servers usually run UTC, so if your host is UTC and you are not, convert the times before you commit the schedule.
Q: Does it support the non-standard six-field syntax with seconds or years?
A: No. This generator emits the five fields that crontab, GitHub Actions schedules and most job runners accept. Seconds-level and @yearly style shortcuts are out of scope.
Your data stays on this device
Cron Generator runs 100% locally. Everything you paste or drop is processed by your own browser and never transmitted. Nothing is stored on our servers — close the tab and it is gone.
Nothing you type is sent to a server, logged, or used for analytics. The page works even with your network disconnected after first load.