Cron expression tester › 0 */3 * * *
What does 0 */3 * * * mean?
Every 3 hours. Runs at 00:00, 03:00, 06:00 … 21:00 — eight times a day.
A balanced cadence for background maintenance and periodic sync tasks.
Next scheduled runs
Calculating…
Field-by-field breakdown
| Value | Field | Meaning |
|---|---|---|
0 | Minute (0–59) | exactly 0 |
*/3 | Hour (0–23) | every 3 step |
* | Day of month (1–31) | every value |
* | Month (1–12) | every value |
* | Day of week (0–6, Sun=0) | every value |
Standard 5-field Vixie/POSIX cron: minute hour day-of-month month day-of-week. Cron uses the server's local timezone unless configured otherwise. Non-standard extensions (@daily, L, W, #, seconds) aren't evaluated here.
Open this schedule in the interactive tester →
Will you know if a every 3 hours run is skipped?
Knowing when 0 */3 * * * should fire is only half of it. The failure that hurts is the silent one — the box was asleep, the trigger broke, the token expired, and nobody noticed. Cronpulse is a free dead-man's-switch: your job pings a URL each time it runs on this schedule, and if a ping goes missing, we alert you by email, Discord, Slack, or webhook.
Monitor a every 3 hours job — free → No signup needed to start.
Related cron schedules
| Schedule | Meaning |
|---|---|
0 */4 * * * | Every 4 hours |
0 */6 * * * | Every 6 hours |
0 */12 * * * | Every 12 hours |
0 0 * * * | Every day at midnight |
0 12 * * * | Every day at noon |
All common cron expressions → · Monitor scheduled jobs → · Monitor an AI agent →