Cron Syntax and Expression Examples
Understand every Cron field, wildcard and operator with practical examples for hourly, daily, weekly and weekday schedules.
The five Cron fields
minute hour day-of-month month day-of-week
| Schedule | Expression |
|---|---|
| Every minute | * * * * * |
| Every 5 minutes | */5 * * * * |
| Every hour | 0 * * * * |
| Daily at midnight | 0 0 * * * |
| Weekdays at 09:00 | 0 9 * * 1-5 |
| First day of each month | 0 7 1 * * |
Operators
*matches every valid value.,lists values, such as1,3,5.-defines a range, such as1-5./defines steps, such as*/15.
Day-of-month and day-of-week behaviour can vary when both are restricted. Check the scheduler documentation and test the result.
More useful schedule examples
| Goal | Expression | Notes |
|---|---|---|
| Every 15 minutes | */15 * * * * | Runs at minute 0, 15, 30 and 45 |
| Every day at 06:30 | 30 6 * * * | Uses the server's configured timezone |
| Every Monday at 09:00 | 0 9 * * 1 | Confirm how the target system numbers Sunday |
| Weekdays at 18:00 | 0 18 * * 1-5 | Monday through Friday |
| Every Sunday at midnight | 0 0 * * 0 | Some systems also accept 7 for Sunday |
| Every three hours | 0 */3 * * * | Runs when the hour is divisible by three |
Cron evaluates each field independently. */15 in the minute field is not the same as waiting 15 minutes after the previous run. It matches fixed points on the clock. Similarly, 0 */3 * * * runs at 00:00, 03:00, 06:00 and so on.
Timezones and missed runs
An expression does not contain a timezone. Traditional Cron normally uses the host timezone, while containers, Kubernetes clusters and managed schedulers may use UTC unless configured otherwise. Daylight saving changes can cause a local time to occur twice or not at all.
Traditional Cron also does not replay a job merely because the machine was offline at the scheduled time. If catching up matters, use a scheduler with missed-run handling or design the task to detect unfinished work.
Validate before deployment
Check the next several run times, test the command independently and confirm the exact Cron dialect. Pay particular attention to midnight, month boundaries, weekdays and daylight saving transitions. For production jobs, log failures and prevent overlapping runs when execution can exceed the interval.
Use the Cron decoder to translate an expression into plain English and preview its next runs.