What is the syntaxe of a cron job expression that runs twice a day?

To schedule a cron job twice a day, use the following syntax (it will run the task at midnight and midday):

  0  0,12 *  *  * 	user-name 	/path/to/command
# |   |   |  |  |
# |   |   |  |  .---- Every day of the week
# |   |   |  .------- Every month
# |   |   .---------- Every day
# |   .-------------- When hours equal zero or twelve (, = list separator)
# .------------------ When minutes equal 0

To schedule a cron job twice a day, use the following syntax (it will run the task at midnight and midday) :

  0  0,12 *  *  * 	user-name 	/path/to/command
# |   |   |  |  |
# |   |   |  |  .---- Every day of the week
# |   |   |  .------- Every month
# |   |   .---------- Every day
# |   .-------------- When hours equal zero or twelve (, = list separator)
# .------------------ When minutes equal 0