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Crontab cron expression: every 3 hours
To run a Crontab job every 3 hours, use:
0 */3 * * *At minute 0, every 3 hours.
Your week at a glance
Upcoming runs
| # | Local | UTC | From now |
|---|
Copy-ready code
Why use this schedule
Eight runs a day: 00:00, 03:00, 06:00 and so on. Handy when you want regular coverage without hourly load.
- Backing up a small database
- Refreshing weather or price feeds
- Sending reminder sweeps
First runs, as an example
Starting from 1 January 2027, evaluated in UTC:
| # | Date and time (UTC) |
|---|---|
| 1 | Fri, 01 Jan 2027, 00:00:00 |
| 2 | Fri, 01 Jan 2027, 03:00:00 |
| 3 | Fri, 01 Jan 2027, 06:00:00 |
| 4 | Fri, 01 Jan 2027, 09:00:00 |
| 5 | Fri, 01 Jan 2027, 12:00:00 |
| 6 | Fri, 01 Jan 2027, 15:00:00 |
Every 3 hours in every dialect
| System | Expression |
|---|---|
| Crontab (this page) | 0 */3 * * * |
| Quartz | 0 0 */3 * * ? |
| Spring | 0 0 */3 * * * |
| Kubernetes | 0 */3 * * * |
| AWS EventBridge | 0 */3 * * ? * |
| Jenkins | H */3 * * * |
| GitHub Actions | 0 */3 * * * |
| node-cron | 0 */3 * * * |
| Apache Airflow | 0 */3 * * * |
| Azure Functions | 0 0 */3 * * * |
| Google Cloud Scheduler | 0 */3 * * * |
Need to translate a different expression? Use the cron converter.
Ready-to-use Crontab config
Drop this into your project. The expression is the one above.
0 */3 * * * /path/to/command >> /var/log/job.log 2>&1The Crontab fields, in order: minute (0-59), hour (0-23), day-of-month (1-31), month (1-12), day-of-week (0-7, 0 and 7 = Sunday).
Things to watch out for in Crontab
- A step such as */15 restarts at the top of each unit, so it only gives even gaps when the step divides 60 (minutes) or 24 (hours).
- Fields are minute, hour, day-of-month, month, day-of-week. There is no seconds field, so one minute is the finest resolution.
- Cron runs in the server's local time zone. Check it with the date command, or put CRON_TZ=Asia/Kolkata above the line on cronie-based systems.
The common mistake with this schedule
Eight runs divide 24 evenly, but across a daylight-saving change the local gap can be two or four hours once a year.
Frequently asked questions
How do I run a Crontab job every 3 hours?
Use 0 */3 * * *. At minute 0, every 3 hours.
What is the every 3 hours cron expression in other systems?
Quartz: 0 0 */3 * * ?; Spring: 0 0 */3 * * *; Kubernetes: 0 */3 * * *. The table on this page lists every dialect.
Which time zone does Crontab use for this schedule?
Cron runs in the server's local time zone. Check it with the date command, or put CRON_TZ=Asia/Kolkata above the line on cronie-based systems.