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?

Cron counts days of the month, so `0 0 */4 * *` restarts on the 1st and the gap at a month boundary can be shorter than 4 days. A single standard 5-field cron cannot preserve exact rolling 4-day spacing across month boundaries. For a predictable approximation, use fixed weekdays such as Monday and Friday (`0 0 * * 1,5`), which produces 4/3-day gaps each week.

All recipes

Cron recipe

Cron job every 4 days: the exact expression

The expression

five-field cron

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, records every run, 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.

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 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?: Cron counts days of the month, so `0 0 */4 * *` restarts on the 1st and the gap at a month boundary can be shorter than 4 days. A single standard 5-field cron cannot preserve exact rolling 4-day spacing across month boundaries. For a predictable approximation, use fixed weekdays such as Monday and Friday (`0 0 * * 1,5`), which produces 4/3-day gaps each week.