Cron expression for every 15 minutes

Free

*/15 * * * * - Every 15 minutes.

Field by field

*/15 * * * * reads: Every 15 minutes. That is 96 runs a day.

What each field of */15 * * * * selects
FieldValueSelects
Minute*/15every 15 minutes: 0, 15, 30 and 45
Hour*every hour
Day of month*any day of the month
Month*every month
Day of week*any day of the week

Worth knowing

  • 96 runs a day, at :00, :15, :30 and :45.
  • Equivalent to 0,15,30,45 * * * *, which some teams prefer because it reads without knowing the step syntax.

Variations

  • */15 9-17 * * 1-5Every 15 minutes during office hours on weekdaysExplain it
  • 7-59/15 * * * *Every 15 minutes, offset to :07, :22, :37, :52Explain it

The same schedule elsewhere

crontab

*/15 * * * * /path/to/job.sh

Runs in the machine's local timezone. crontab -e to edit.

GitHub Actions

on:
  schedule:
    - cron: "*/15 * * * *"

Always UTC. Nothing more often than every 5 minutes, and runs can start late when GitHub is busy.

Kubernetes CronJob

spec:
  schedule: "*/15 * * * *"
  timeZone: "Asia/Kolkata"

timeZone needs Kubernetes 1.27 or later; without it the controller's zone applies, usually UTC.

Spring @Scheduled

@Scheduled(cron = "0 */15 * * * *")

Six fields: seconds come first. Days are written as names, which Spring and cron read alike.

Quartz

0 0/15 * * * ?

One of day-of-month and day-of-week must be ?. Quartz counts days 1-7 from Sunday, so names are safer than numbers.

AWS EventBridge

cron(0/15 * * * ? *)

Six fields, the last one the year. UTC unless the schedule sets a timezone. Days count from Sunday, as in Quartz.

systemd timer

[Timer]
OnCalendar=*-*-* *:00/15:00
Persistent=true

Persistent=true runs a job that was missed while the machine was off, once it is back.