Cron every minute: the expression, explained, in Docker
The cron expression for “every minute” is * * * * *. This page shows what each field does, the next five times it will fire, the mistake most people make with it, and a working Docker example you can paste.
The expression
* * * * *
| Field | Value | Meaning |
|---|---|---|
| minute | * | every minute |
| hour | * | every hour |
| day of month | * | every day of month |
| month | * | every month |
| day of week | * | every day of week |
Next five runs (UTC, from now)
- 2026-09-17 23:07 UTC
- 2026-09-17 23:08 UTC
- 2026-09-17 23:09 UTC
- 2026-09-17 23:10 UTC
- 2026-09-17 23:11 UTC
Mistakes people make with this schedule
- Running a slow job every minute: if one run takes 90 seconds, two overlap. Use a lock, or a longer interval.
- Assuming the server clock is your clock. Cron runs in the machine’s timezone unless the runtime says otherwise; the examples here are UTC.
- No lock around a job that might overlap itself, and no alert when it silently stops. That second one is what Supercrontab is for.
Run it in your stack
# Dockerfile RUN apk add --no-cache curl RUN echo '* * * * * curl -fsS http://app:3000/cron/run' > /etc/crontabs/root CMD ["crond", "-f", "-l", "2"]
Or skip the sidecar: expose the route and let Supercrontab call it.
Questions
Does * * * * * run in my local time?
Only if the scheduler is configured for it. crontab uses the system timezone; Vercel and GitHub Actions always use UTC; Laravel and node-cron take a timezone option. In Supercrontab the timezone is a field on the job.
What if the previous run is still going?
Classic cron starts the next run anyway. Add a lock (flock on Linux, withoutOverlapping() in Laravel) or let Supercrontab skip the tick while the previous request is open.
Is there a shorter way to write this?
No. The five-field form is the shortest portable version.