Cron recipe
Cron job every 3 days: the exact expression
The expression
0 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 at midnight on days 1, 4, 7, … 31 of each month. The `*/3` step is evaluated inside the day-of-month field and restarts when a new month begins; it is not a continuous 72-hour interval.
When to use it
Billing and dunning follow-ups
Retry failed payments or advance an account-recovery workflow on a three-day calendar cadence.
ERP and inventory reconciliation
Compare slower-moving operational data without running a full sync every night.
Common variations
0 9 */3 * *The same stepped calendar days at 9:00am instead of midnight.
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, from $2.99/mo and scaling as you grow.
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 days?
- Use 0 0 */3 * * (standard five-field cron). Verify the next run times in the free cron debugger before you deploy.
- Can Crontap run this schedule?
- `0 0 */3 * *` is a calendar pattern, so the count restarts on day 1 of each month and the month-boundary gap can be shorter than 3 days. Crontap can run that expression as written. For a strict rolling 3-day interval, choose Human Readable and enter `3 days` instead.