Cron expression for every 5 minutes

The cron expression */5 * * * * runs a job every 5 minutes — at :00, :05, :10, :15 and so on through every hour. The standard 5-field syntax works in Linux crontab, Kubernetes CronJob, GitHub Actions and any scheduler that uses Unix cron. AWS EventBridge needs a 6-field form: cron(*/5 * * * ? *).

Quick reference

What does “every 5 minutes” actually mean?

The expression fires on absolute wall-clock minutes — :00, :05, :10, :15, :20, :25, :30, :35, :40, :45, :50, :55. Twelve runs per hour, 288 runs per day. It does NOT mean “5 minutes after the previous run finished”.

This matters when a run can take longer than the interval. If your job sometimes runs 7 minutes, you’ll have overlap. What happens then depends on the scheduler:

• Linux cron — starts a new process at :05 regardless. Two copies run concurrently.
• Kubernetes CronJob — depends on concurrencyPolicy (default Allow lets them stack; set Forbid to skip the new run, Replace to kill the old one).
• AWS EventBridge — invokes the target at :05 regardless. If the target is a Lambda with reserved concurrency 1, the second invocation throttles.

For sub-15-minute schedules this stacking risk is real — set concurrency policies explicitly.

Variations

How do I use it on each platform?

Linux crontab:

*/5 * * * * /usr/local/bin/check-disk

Kubernetes CronJob:

apiVersion: batch/v1
kind: CronJob
metadata:
  name: check-disk
spec:
  schedule: "*/5 * * * *"
  concurrencyPolicy: Forbid          # important for short intervals
  jobTemplate:
    spec:
      template:
        spec:
          restartPolicy: OnFailure
          containers:
            - name: check
              image: my-org/check-disk:1.0

AWS EventBridge (CLI):

aws events put-rule \
  --name check-disk \
  --schedule-expression "cron(*/5 * * * ? *)"

GitHub Actions:

on:
  schedule:
    - cron: '*/5 * * * *'      # NOTE: GitHub min interval is actually 5 min

GitHub Actions enforces a 5-minute minimum, so this is the fastest schedule you can request. Anything more frequent is silently coalesced.

Common mistakes

Forgetting the trailing year in AWS. cron(*/5 * * * ?) is rejected — needs * at the end for year, even when you don’t constrain it.

Using * for both day-of-month and day-of-week in AWS. Replace exactly one with ?. The AWS parser refuses to accept both as *.

Assuming 5-minute schedules are “free” in serverless. EventBridge invokes are billed per million; Lambda invocations cost per request. 12/hour × 24h × 30 days = 8,640 invocations/month per rule. For 50 rules, that’s 432,000 invocations — measure the bill before scaling.

For other schedules see common cron schedules, or build a custom expression with the Cron Expression Builder.