What is the cron expression for every 3 hours?

Use 0 */3 * * * (standard five-field cron). Verify the next run times in the free cron debugger before you deploy.

Can Crontap run this schedule?

Yes. Crontap fires five-field expressions on your chosen cadence (1-minute floor on Pro), with per-schedule IANA timezones, retries, and failure alerts. Pro is $3.25/mo billed annually.

All recipes

Cron recipe

Cron job every 3 hours: the exact expression

The expression

five-field cron

0 */3 * * *

Paste it into crontab -e, your platform cron config, or tool.crontap.com/cronjob-debugger to preview the next runs.

What it does

Runs eight times per day at 00:00, 03:00, 06:00, … 21:00 when minute is `0`.

When to use it

Cross-region replication lag checks
Eight checkpoints per day without waking on-call every hour.

Run this with Crontap

External HTTP cron hits your URL on this schedule, stores every response, and emails you when a run fails. No daemon on the box, no drift when the server reboots. Pro schedules down to a 1-minute cadence; $3.25/mo annual flat for unlimited jobs.

Schedule this interval Preview in the cron debugger →

Related recipes

More patterns in the cron syntax cheat sheet and what is a cron job in Linux.

FAQ

What is the cron expression for every 3 hours?: Use 0 */3 * * * (standard five-field cron). Verify the next run times in the free cron debugger before you deploy.
Can Crontap run this schedule?: Yes. Crontap fires five-field expressions on your chosen cadence (1-minute floor on Pro), with per-schedule IANA timezones, retries, and failure alerts. Pro is $3.25/mo billed annually.