Cron Expression: Every 12 Hours
The expression is 0 */12 * * *. Paste it above to read it in English and preview the next run times. Below: what times it actually fires and the variations.
The expression
0 */12 * * * runs a job every 12 hours — at 00:00 and 12:00 (midnight and noon) every day.
Field by field
0 pins it to the top of the hour; */12 steps the hour field by 12, giving hours 0 and 12. The remaining * * * leave day, month and weekday open.
Pick your own two times
Want 6am and 6pm instead? Use 0 6,18 * * *. The step form always starts at hour 0, so use a list for arbitrary pairs.
FAQ
What times does 0 */12 * * * run?
Midnight (00:00) and noon (12:00) every day.
How do I run every 12 hours at 6am and 6pm?
Use 0 6,18 * * * — a list, because the step form always starts at hour 0.
Is 0 */12 * * * the same as 0 0,12 * * *?
Yes, they are identical.