Curated cron expression
Every Minute Cron Expression: * * * * *
Learn what * * * * * means, when an every-minute cron job fires, its operational cost, timezone behavior, and how to adapt it for Kubernetes, AWS, Spring, Vercel, GitHub Actions, and systemd.
Meaning at a glance
* * * * *
Run once every minute
At second 0 of every minute, subject to scheduler delay and runtime behavior.
Next-run example: If the clock is 10:07:24, the next nominal runs are 10:08, 10:09, 10:10, and 10:11.
How * * * * * works
The expression * * * * * matches every possible minute. Because all five fields are wildcards, there are no hour, date, month, or weekday restrictions.
This is the highest-frequency schedule available in traditional minute-level cron. It produces 60 runs per hour and 1,440 runs per day, so a small leak, slow query, or duplicate side effect compounds quickly.
| Field | Value | Meaning |
|---|---|---|
| Minute | * | Every minute, 0 through 59 |
| Hour | * | Every hour |
| Day of month | * | Every calendar day |
| Month | * | Every month |
| Day of week | * | Every weekday |
Good use cases
- Short-lived health probes
- Small queue drains
- Near-real-time cache refresh
- Development-only polling
Timezone and daylight-saving behavior
The cadence is the same in every timezone, although displayed wall-clock timestamps differ.
An every-minute cadence has no special business-hour meaning, but local clock labels can skip or repeat during DST transitions. Use UTC identifiers for logs and idempotency.
The expression does not contain a timezone. The scheduler supplies that context. Use the next-run preview above in the same IANA timezone as production, then confirm the target platform's own timezone rules.
Platform compatibility and converted expressions
The source expression is five-field Unix cron. Use the exact equivalent below rather than adding or removing fields by sight.
| Platform | Status | Expression | What to know |
|---|---|---|---|
| Unix crontab | Ready | * * * * * | Use directly in a normal five-field user crontab. |
| Kubernetes CronJob | Ready | * * * * * | Use as spec.schedule; set spec.timeZone when local wall-clock behavior matters. |
| GitHub Actions | Unsupported | * * * * * | Not supported: GitHub Actions has a five-minute minimum. |
| Vercel Cron Jobs | Plan / behavior limit | * * * * * | Minute-level grammar is valid on eligible plans; Hobby permits only once per day. |
| AWS EventBridge Scheduler | Convert | cron(* * * * ? *) | Convert to AWS minute-first cron(...), add the required year, and use ? in one day field. |
| Spring @Scheduled | Convert | 0 * * * * * | Use Spring’s six fields by prepending seconds and set zone explicitly when needed. |
| systemd timer | Convert | minutely | Use OnCalendar syntax and validate it with systemd-analyze calendar on the target host. |
Edge cases to check before deployment
- A job that takes longer than one minute can overlap itself.
- A fleet of hosts fires at the same minute boundary and can create a thundering herd.
- GitHub Actions does not allow schedules more frequent than every five minutes.
- Vercel Hobby does not allow an every-minute cron job.
Frequently asked questions
What does the cron expression * * * * * mean?
* * * * * means “run once every minute.” At second 0 of every minute, subject to scheduler delay and runtime behavior.
What are the next run times for * * * * *?
If the clock is 10:07:24, the next nominal runs are 10:08, 10:09, 10:10, and 10:11. Exact timestamps depend on the scheduler timezone and the current time.
What timezone does * * * * * use?
The cadence is the same in every timezone, although displayed wall-clock timestamps differ.
Can I use * * * * * on every scheduling platform?
No. It is a five-field Unix expression. Some platforms accept it directly, while AWS EventBridge Scheduler, Spring, and systemd require the converted form shown in the compatibility table.