Hourly
0 */4 * * *
Run six times a day, 00:00, 04:00, … 20:00.
This preview is live: the table below shows the actual next run times for 0 */4 * * * in your time zone, recomputed in your browser. Change the expression, dialect, or zone to experiment, then copy the result.
What 0 */4 * * * means
0 */4 * * * divides the day into six even blocks, firing at midnight, 04:00, 08:00, 12:00, 16:00, and 20:00. It is a clean, regular cadence (24 ÷ 4 = 6) that maps neatly onto a six-times-a-day operational rhythm.
Four hours is a common interval for medication-style reminders, shift handovers, and batch jobs that want to touch the data a handful of times a day without the overhead of hourly runs.
Field-by-field breakdown
Unix cron has five fields. Here is what each one is doing in this expression:
| Field | Value | Meaning |
|---|---|---|
| Minute | 0 | minute = 0 |
| Hour | */4 | every 4 (step) across hour |
| Day of month | * | every day-of-month |
| Month | * | every month |
| Day of week | * | every day-of-week |
Every 4 hours in every scheduler
The same cadence written for the seven cron dialects you are most likely to meet. Copy the line for the system you target, the field count and day-of-week numbering differ between them.
| Scheduler | Expression | Copy |
|---|---|---|
| Unix / crontab | 0 */4 * * * | |
| GitHub Actions | 0 */4 * * * | |
| Kubernetes CronJob | 0 */4 * * * | |
| Vercel Cron | 0 */4 * * * | |
| Quartz | 0 0 */4 * * * * | |
| Spring | 0 0 */4 * * * | |
| AWS EventBridge | 0 */4 * * * * |
When you would use 0 */4 * * *
- Six-times-daily inventory or price refreshes.
- Periodic backups with a manageable retention count.
- Rotating API keys or re-issuing short-lived credentials.
The gotcha worth knowing
If you need the runs anchored to a non-midnight time (say 02:00, 06:00, …) you cannot do it with */4 alone, list the hours explicitly: 0 2,6,10,14,18,22 * * *.
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0 */4 * * * FAQ
What does the cron expression 0 */4 * * * mean?
0 */4 * * * means: Run six times a day, 00:00, 04:00, … 20:00. 0 */4 * * * divides the day into six even blocks, firing at midnight, 04:00, 08:00, 12:00, 16:00, and 20:00. It is a clean, regular cadence (24 ÷ 4 = 6) that maps neatly onto a six-times-a-day operational rhythm.
How do I write "every 4 hours" in GitHub Actions?
Use 0 */4 * * * in the schedule's cron field. If you need the runs anchored to a non-midnight time (say 02:00, 06:00, …) you cannot do it with */4 alone, list the hours explicitly: 0 2,6,10,14,18,22 * * *.
How do I write "every 4 hours" for AWS EventBridge?
EventBridge uses six fields with a required year and a ? placeholder in one day field: 0 */4 * * * *. Wrap it as cron(0 */4 * * * *) in the console or CloudFormation.
What is the Quartz equivalent of 0 */4 * * *?
Quartz is seconds-first with a trailing year, so the equivalent is 0 0 */4 * * * *. Remember Quartz numbers Sunday as 1, the opposite of Unix.
Related cron patterns
More cron tools
Browse the full set of cron pattern pages, or jump to the interactive tools: the cron expression builder for designing a schedule from scratch, the cron cheat sheet for a side-by-side reference, the cron timezone translator for moving a schedule between zones and dialects, and the GitHub Actions cron picker for DST-stable CI schedules.