Cron expression for every minute

The expression * * * * * runs a job every single minute, all day, every day — 60 times an hour, 1,440 times a day. All five fields are *, so nothing is restricted: every minute of every hour of every day of every month qualifies.

This is the most frequent schedule standard cron can express. It is useful for near-real-time polling, but it is also the cadence people reach for by accident when they meant "every minute during some window". If you only need business hours, constrain the hour and weekday fields — * 9-17 * * 1-5 runs every minute from 9 AM to 5:59 PM on weekdays instead.

Two cautions at this frequency. First, a job that occasionally takes longer than a minute will overlap itself; guard it with a lock (for example flock) or your scheduler's concurrency policy. Second, per-minute jobs dominate logs and can mask real signal — make sure the work is cheap and the output quiet.