Cron twice a day
Twice a day in cron is a list in the hour field, such as 0 9,21 * * * (Unix) or 0 0 9,21 * * ? (Quartz, Spring); next runs are calculated in your browser.
0 9,21 * * *
0 0 9,21 * * ?
cron(0 9,21 * * ? *)
Read by our parser as: At 9:00 AM and 9:00 PM, every day. Open in the cron checker
Next 10 runs
Calculating in your browser...
- 1
- 2
- 3
At a glance
- Accepts
- Nothing to enter - the schedule is preset on the page
- Outputs
- The expression in Unix, Quartz/Spring and AWS form, plus its next 10 run times
- Where it runs
- Entirely in your browser, on your device
- What leaves your device
- Nothing - what you type stays in this tab
- Limits
- Run times use your browser's timezone or UTC; real schedulers can start a run late
- Account
- Not required - there is no sign-up
- Price
- Free, with no watermark and no usage cap
- Made by
- Visrut
What it means
Put two hours in the hour field, separated by a comma: 0 9,21 * * * runs at 9:00 and 21:00 every day. The hours don't have to be 12 apart; 30 8,17 * * * runs at 8:30 and 17:30. Spring's docs show the same pattern as 0 0 6,19 * * * (6 AM and 7 PM).
When this is the right schedule
Use it when a job should catch both ends of the day: a morning and evening digest, start-of-day and end-of-day stock levels, twice-daily backups.
When to pick something else
Look elsewhere when you need different minutes for the two runs (9:00 and 21:30). A single cron line shares one minute field, so that takes two lines.
Things to watch
0 */12 * * * is also twice a day
It runs at 00:00 and 12:00 only, because the step starts at hour 0. Use the list form when you want to choose the hours.
Different minutes need two lines
0 9 * * * and 30 21 * * * as separate entries. In Kubernetes or GitHub Actions that means two schedules (GitHub allows several cron entries under schedule).
Hours are in the scheduler's timezone
9 and 21 in UTC are 9 and 21 in London in winter but 10 and 22 in summer (BST). If the times should follow local clocks, set the timezone on the schedule (GitHub timezone, Kubernetes .spec.timeZone, AWS Scheduler's schedule timezone).
Frequently asked questions
How do I run a cron job at 8 AM and 8 PM?
0 8,20 * * *. In Quartz or Spring: 0 0 8,20 * * ?.
Is 0 0,12 * * * the same as 0 */12 * * *?
Yes. Both run at 00:00 and 12:00.