Cron expression: every 30 seconds

Open in the Cron Expression Generator →

What * * * * * means

Cron reads five fields from left to right: minute, hour, day of the month, month and day of the week. This page shows the closest standard expression (every minute) and how to get a 30-second interval.

Next runs

Calculated in your browser for your time zone. On a server, cron uses the server’s time zone (often UTC).

1. Enable JavaScript to see the next run times.

Typical uses

• Very frequent polling

Good to know

Standard cron can’t go below one minute. Run a job every minute that runs twice: * * * * * /job.sh; sleep 30; /job.sh, or use a systemd timer (OnCalendar=*:*:0/30) or a long-running worker.

Use it in crontab, GitHub Actions, Kubernetes and Node.js

crontab (crontab -e):

* * * * * /usr/local/bin/my-job.sh >> /var/log/my-job.log 2>&1

GitHub Actions (times are UTC): GitHub Actions runs schedules at most every 5 minutes, so this one would be throttled there.

on:
  schedule:
    - cron: '* * * * *'

Kubernetes CronJob:

apiVersion: batch/v1
kind: CronJob
metadata:
  name: my-job
spec:
  schedule: "* * * * *"
  concurrencyPolicy: Forbid
  jobTemplate:
    spec:
      template:
        spec:
          restartPolicy: OnFailure
          containers:
            - name: my-job
              image: alpine:3
              command: ["sh", "-c", "echo running"]

Node.js (node-cron):

import cron from 'node-cron';
cron.schedule('* * * * *', () => {
  // your job
});

Related schedules

• Every minute — * * * * *
• Every 2 minutes — */2 * * * *
• Every 5 minutes — */5 * * * *
• Every 10 minutes — */10 * * * *
• Every 15 minutes — */15 * * * *
• Every 20 minutes — */20 * * * *
• Every 30 minutes — */30 * * * *