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Cron Expression Generator & Explainer

Generate a cron expression from a plain schedule picker, or paste an existing one to get a plain-English explanation and a field-by-field breakdown.

Tool not available.

Most-Copied Cron Expressions

ExpressionMeaning
* * * * *Every minute
*/5 * * * *Every 5 minutes
0 * * * *Top of every hour
0 3 * * *Daily at 03:00
30 8 * * 1-5Weekdays at 08:30
0 0 1 * *First day of every month at midnight
0 4 * * 0Every Sunday at 04:00

How the Tool Works

  1. Compose mode: pick frequency (minutes, hourly, daily, weekly, monthly), then the exact minute, hour, or day.
  2. The tool builds the five-field cron expression and shows the next few matching run times.
  3. Explain mode: paste any 5-field expression to see each field decoded and the whole schedule in a sentence.
  4. A cheatsheet of the most-copied expressions (every 5 minutes, 3 AM daily, weekdays at noon…) is one click away.
Formula & Technical Standard
Five fields: minute (0-59) · hour (0-23) · day-of-month (1-31) · month (1-12) · day-of-week (0-6, 0 = Sunday). * = any; */n = every n; a-b = range; a,b = list.

Example Input & Output

Every weekday morning report
Input: Pick: weekdays at 08:30
Output: 30 8 * * 1-5
Minute 30, hour 8, any day of month, any month, Monday through Friday — the standard weekday-morning schedule.
Decoding a mystery cron
Input: */15 9-17 * * *
Output: Every 15 minutes between 09:00 and 17:59, every day
The */15 repeats within each hour; the 9-17 hour range limits it to business hours — a common polling pattern for APIs.

Common Questions

Which cron dialect does this use?

The classic five-field POSIX crontab format used by Linux/Unix cron. Some schedulers add a sixth "seconds" field (Quartz) or support @hourly shortcuts; five-field expressions work in the vast majority of systems.

What is the difference between */5 in minutes and hours?

*/5 in the minute field means "every 5th minute of every hour" (00, 05, 10…). */5 in the hour field means every 5th hour (00:00, 05:00, 10:00…). The field position changes the meaning completely.

What happens if both day-of-month and day-of-week are restricted?

Classic cron ORs them: the job runs when either matches. Setting 13 as day-of-month and Friday as weekday runs on the 13th of every month AND every Friday — a frequent surprise documented in most crontab manuals.

Does cron account for daylight saving time?

Cron fires by local server time, so schedules can shift or skip an hour at DST transitions. For critical schedules run the server in UTC or use a scheduler with explicit timezone support.

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