Cron: twice a day (0 0,12 * * *)
The cron expression 0 0,12 * * * runs a job twice a day — here's exactly what each field means and how to use it.
| Field | Value | Means |
|---|---|---|
| Minute | 0 | at 0 |
| Hour | 0,12 | at 0, 12 |
| Day of month | * | every day |
| Month | * | every month |
| Day of week | * | every day |
Notes
A cron expression has five fields — minute, hour, day-of-month, month, day-of-week — each accepting a number, * (every), */n (every n), a list (1,15) or a range (1-5). Day-of-week runs Sunday=0 to Saturday=6.
Note on timezone: plain cron runs in the server's local time. GitHub Actions cron always runs in UTC — convert your intended local time before setting it.
Other schedules: every minute · every 5 minutes · every 10 minutes · every 15 minutes · every 30 minutes · every hour · every 2 hours · every 6 hours · every 12 hours · every day at midnight
Frequently asked questions
What does the cron expression "0 0,12 * * *" mean?
0 0,12 * * * runs twice a day. Runs at 00:00 and 12:00 every day — midnight and noon.
How do I add "0 0,12 * * *" to crontab?
Run crontab -e and add a line: 0 0,12 * * * /path/to/script.sh — then save. Use crontab -l to confirm it's installed.
Does "0 0,12 * * *" run in UTC or local time?
System cron uses the server's local timezone; GitHub Actions and most CI schedulers use UTC. Adjust the hour field for the timezone difference.