0 */12 * * *
Cron reads this as: minute 0, past every 12th hour.
Next 5 runs
Computed in your browser's local time zone. Cron itself evaluates against the server's zone, which on most cloud hosts is UTC — see time zones & DST if that distinction matters here.
- Calculating…
When to use this schedule
Fires at midnight and noon. Useful when you want a daily job with one retry built into the schedule, or for syncing with a partner system that publishes twice a day.
What to watch out for
Both runs land on high-traffic hours — midnight is when every nightly job on the fleet starts, and noon catches peak load on a lot of systems. 0 3,15 * * * gives the identical twelve-hour spacing in much quieter windows. If the two runs are not meant to be interchangeable, write them as separate crontab lines with separate log destinations so you can tell them apart.
The crontab line
0 */12 * * * /usr/local/bin/your-job.sh >> /var/log/your-job.log 2>&1Redirect the output somewhere you will actually read it — by default cron mails it, and on a host with no mail transport that means it is discarded. See the crontab guide for the surrounding syntax.
Related schedules
| Expression | Schedule |
|---|---|
0 0,12 * * * | Same schedule, written as a list |
0 3,15 * * * | Every 12 hours, in quieter hours |
0 0 * * * | Once a day |
Build your own
Need something this page does not cover? Compose it field by field in the visual builder, or paste an expression you already have into the explainer for a per-field breakdown. The examples library collects sixty schedules in one place, and the guides cover crontab syntax, time zones, troubleshooting and production practices.