Cron every minute
* * * * * — Five asterisks: every minute of every hour of every day. It is the finest resolution standard cron has — the daemon wakes once a minute and runs everything that matches.
Runs
Try one
The same schedule in every dialect
| Where | Expression | |
|---|---|---|
| Linux / Unix crontab, Kubernetes, GitHub Actions | * * * * * | explain |
| Quartz Scheduler | 0 * * ? * * | explain |
| AWS EventBridge | cron(* * * * ? *) rate(1 minute) | explain |
Spring @Scheduled | 0 * * * * * | explain |
| Jenkins | * * * * * | H calculator |
systemd timer OnCalendar= | *-*-* *:*:00 | test |
AWS rate(1 minute) repeats at a fixed interval from when the rule or schedule was created, so it is not aligned to the clock the way the cron() form is.
Things to know
- GitHub Actions will not run a schedule more often than every five minutes, so
* * * * *there behaves like*/5at best. - In Jenkins,
H/1is the same as plainH(one minute per hour), not every minute; Jenkins spells "every minute" as* * * * *and suggestsHinstead. The table shows* * * * *for Jenkins for that reason. - If a run can take longer than a minute, wrap the command in
flock -n /tmp/job.lockso runs cannot pile up — the crontab line builder adds it for you.
Variations
| Expression | Runs |
|---|---|
| * 9-17 * * 1-5 | every minute during office hours on weekdays |
| */2 * * * * | every other minute |
| */10 * * * * * | every 10 seconds (node-cron, six fields) |
How to use this schedule
- Open your crontab with
crontab -e(or the scheduler's config file). - Add a line with the expression followed by the command:
* * * * * /usr/local/bin/job.sh. Use absolute paths — cron runs with a minimalPATH. - Save. cron picks the change up automatically; check the next run times above, in the time zone your server uses.
- Redirect output if you want to keep it: append
>> /var/log/job.log 2>&1. The crontab line builder assembles the whole line.
FAQ
Is "* * * * *" the same on every server?
The five-field form means the same thing in Linux cron, Kubernetes, GitHub Actions and most libraries. The clock it follows differs:
a Linux server uses its own time zone (or CRON_TZ on cronie), GitHub Actions and AWS EventBridge rules use UTC unless a time zone is configured, and Kubernetes uses the controller's zone unless .spec.timeZone is set.
Why do Quartz and AWS need a "?"
Both require exactly one of day-of-month and day-of-week to be ?, meaning "no specific value"; they refuse an expression that restricts both, or leaves both as *.
How do I check it will run when I expect?
The widget above lists the next runs in the time zone you choose, and flags any run that lands in a daylight-saving gap or a repeated hour. For a whole crontab, paste it into the crontab viewer.