Cheat Sheets · Cron Cheat Sheet · Cron Every 15 Minutes — Crontab Example

Cron Every 15 Minutes — Crontab Example

*/15 * * * *

Runs every 15 minutes — at minutes 0, 15, 30, 45 (quarter hours).

Field by field

Field	Value	Meaning
`Minute`	`*/15`	Every 15th minute (0, 15, 30, 45)
`Hour`	`*`	Every hour
`Day of month`	`*`	Every day
`Month`	`*`	Every month
`Day of week`	`*`	Every day of the week

Four runs per hour, aligned to quarter hours. You can spell the same schedule as an explicit list — 0,15,30,45 * * * * — which some people find more readable, but */15 is idiomatic.

*/15 * * * * /usr/local/bin/check-alerts.sh

Related schedules

*/5 * * * * Every 5 minutes */30 * * * * Every 30 minutes 0 * * * * Every hour, on the hour

FAQ

How do I run at 7, 22, 37, 52 instead?
Use a ranged step: 7-59/15 * * * *. The step counts from the start of the range, not from 0.

Four runs a day skipped during DST change?
On DST transition days a local-time cron can fire twice or not at all for one hour. UTC scheduling avoids it entirely.

Is this too frequent for an API poller?
96 calls per day per endpoint is modest. Add jitter via an offset step if you are one of many clients hitting the same vendor.

Stop memorizing — build it interactively

Try this schedule in the Cron Editor

Full reference: Cron Cheat Sheet