Hourly
0 */12 * * *Run twice a day — 00:00 and 12:00.
This preview is live: the table below shows the actual next run times for 0 */12 * * * in your time zone, recomputed in your browser. Change the expression, dialect, or zone to experiment, then copy the result.
0 */12 * * * means0 */12 * * * fires at midnight and noon — twice a day, twelve hours apart. It is the simplest twice-daily schedule and reads clearly: the */12 step lands on hours 0 and 12 only.
Twice-daily is a frequent choice for digests and reconciliation jobs that want a morning and an evening pass, or for syncs where once a day is too stale but hourly is overkill. If you want specific times rather than midnight/noon, list them: 0 6,18 * * *.
Unix cron has five fields. Here is what each one is doing in this expression:
| Field | Value | Meaning |
|---|---|---|
| Minute | 0 | minute = 0 |
| Hour | */12 | every 12 (step) across hour |
| Day of month | * | every day-of-month |
| Month | * | every month |
| Day of week | * | every day-of-week |
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 */12 * * * | |
| GitHub Actions | 0 */12 * * * | |
| Kubernetes CronJob | 0 */12 * * * | |
| Vercel Cron | 0 */12 * * * | |
| Quartz | 0 0 */12 * * * * | |
| Spring | 0 0 */12 * * * | |
| AWS EventBridge | 0 */12 * * * * |
0 */12 * * *0 */12 * * * is locked to 00:00 and 12:00. For an asymmetric twice-daily schedule (say 09:00 and 17:00) you must enumerate the hours — the step form cannot express uneven gaps.
0 */12 * * * means: Run twice a day — 00:00 and 12:00. 0 */12 * * * fires at midnight and noon — twice a day, twelve hours apart. It is the simplest twice-daily schedule and reads clearly: the */12 step lands on hours 0 and 12 only.
Use 0 */12 * * * in the schedule's cron field. 0 */12 * * * is locked to 00:00 and 12:00. For an asymmetric twice-daily schedule (say 09:00 and 17:00) you must enumerate the hours — the step form cannot express uneven gaps.
EventBridge uses six fields with a required year and a ? placeholder in one day field: 0 */12 * * * *. Wrap it as cron(0 */12 * * * *) in the console or CloudFormation.
Quartz is seconds-first with a trailing year, so the equivalent is 0 0 */12 * * * *. Remember Quartz numbers Sunday as 1, the opposite of Unix.
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.