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Cron Reference

Every 30 Minutes

Runs twice per hour at :00 and :30.

Cron Expression

*/30 * * * * Test in tool

Every 30 minutes

Expression Breakdown

Minute Hour Day Month Weekday
*/30 * * * *
every 30 any any any any

Next 5 Scheduled Runs

  • Saturday, June 13 2026 at 9:00 PM
  • Saturday, June 13 2026 at 9:30 PM
  • Saturday, June 13 2026 at 10:00 PM
  • Saturday, June 13 2026 at 10:30 PM
  • Saturday, June 13 2026 at 11:00 PM

Times are relative to the server's local clock at page load.

Common Use Cases

  • Email and notification digests
  • Inventory / stock checks
  • Incremental backup snapshots

How to Install

Linux / macOS (crontab)

Run crontab -e and add this line:

*/30 * * * * /path/to/your/script.sh

Python (APScheduler / cron-style)

scheduler.add_job(my_func, 'cron',
    minute='*/30',
    hour='*',
    day='*',
    month='*',
    day_of_week='*')

GitHub Actions (schedule)

on:
  schedule:
    - cron: '*/30 * * * *'

Frequently Asked Questions

What does */30 * * * * mean?
The job fires at minute 0 and minute 30 of every hour — 48 times per day.
What is the difference between */30 and 0,30?
They produce identical results for the minute field. */30 is shorthand for every 30th minute starting at 0; 0,30 explicitly lists both values.