Cron Every 3 Hours
Set up a cron job every 3 hours with 0 */3 * * *. Includes complete field-by-field explanation, practical scenarios, and platform compatibility.
Cron Expression
0 */3 * * *
Field Breakdown
| Field | Value | Meaning |
|---|---|---|
| Minute | 0 | At 0 |
| Hour | */3 | Every 3rd hour |
| Day of Month | * | Every day of the month (1–31) |
| Month | * | Every month (1–12) |
| Day of Week | * | Every day of the week (Sun–Sat) |
Detailed Explanation
The cron expression 0 */3 * * * schedules a task to run once every three hours, at the top of every third hour.
Field-by-field breakdown:
0(Minute): At minute 0 only. The task fires at the start of the hour.*/3(Hour): Every 3rd hour, starting from hour 0. The step value/3triggers execution at hours 0, 3, 6, 9, 12, 15, 18, and 21.*(Day of Month): Every day from 1 through 31. No restriction on the day of the month.*(Month): Every month from January through December. No restriction on the month.*(Day of Week): Every day of the week from Sunday through Saturday. No restriction on the day.
This means your task will execute 8 times per day, once every three hours. This schedule provides a moderate cadence that is well suited for tasks requiring periodic attention without the overhead of hourly execution. The three-hour gap gives long-running processes ample time to finish. It is often used for incremental database backups, social media content scheduling, and periodic cache warming. This expression is supported by standard cron on Linux/macOS, as well as cloud services like AWS CloudWatch, Google Cloud Scheduler, and GitHub Actions.
Use Case
Great for running incremental database backups that capture recent changes without the storage overhead of hourly full backups.
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Every 3 hours
Next 10 Executions
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