Cron recipe
Cron job every 30 minutes: the exact expression
The expression
five-field cron
*/30 * * * *Paste it into crontab -e, your platform cron config, or tool.crontap.com/cronjob-debugger to preview the next runs.
What it does
Runs at the top and bottom of each hour (:00 and :30).
When to use it
Medium-frequency syncs
Good default when minute-level is overkill but hourly is too slow.
Twice-hourly digest prep
Aggregate metrics before a Slack or email summary job fires.
Common variations
15,45 * * * *Twice per hour on the half-quarter marks instead of :00/:30.
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.
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 30 minutes?
- Use */30 * * * * (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.