Cron recipe
Cron job every 4 days: the exact expression
The expression
0 0 */4 * *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, 5, 9, 13, 17, 21, 25, and 29 of each month. Because the day-of-month step resets monthly, the gap after the final run varies with the length of the month.
When to use it
Warehouse snapshot refreshes
Rebuild heavier reporting snapshots several times per month without a daily warehouse run.
Content and search cache rebuilds
Refresh slower-changing indexes on predictable dates that are easy to inspect.
Common variations
30 2 */4 * *The same stepped calendar days at 2:30am for an overnight maintenance window.
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 4 days?
- Use 0 0 */4 * * (standard five-field cron). Verify the next run times in the free cron debugger before you deploy.
- Can Crontap run this schedule?
- `0 0 */4 * *` is a calendar pattern, so the count restarts on day 1 of each month and the month-boundary gap can be shorter than 4 days. Crontap can run that expression as written. For a strict rolling 4-day interval, choose Human Readable and enter `4 days` instead.