Crontab Translator
Cron syntax is five fields of pure punctuation. Paste an expression like 0 4 * * 1 and see exactly when it runs — before your backup fires at the wrong time.
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| Field | Value | Meaning |
|---|
Standard 5-field cron (Vixie cron, the one behind crontab -e on Linux and macOS): minute, hour, day of month, month, day of week. When both day fields are restricted, the job runs when either matches. Weekdays are 0–7 with both 0 and 7 meaning Sunday.
Cron in one minute
The five fields read in order: minute (0–59), hour (0–23), day of the month (1–31), month (1–12) and day of the week (0–7, where both 0 and 7 are Sunday). Stars mean “every”, and the most common real-world example is 0 4 * * * — every night at 4:00 AM, the classic slot for backups because nothing else is using the server or the disks.
Edit your schedule with crontab -e; each line is a schedule followed by the command to run. Two gotchas: cron uses the server's timezone (set TZ on the host or in the container), and commands run with a minimal environment, so use absolute paths — and if the command needs to run as root, that usually means the root crontab via sudo crontab -e.