How often you do this in a cron? - 0 * * * *

Question

0 * * * *

I use crontab. How often this is done in cron?

Answer 1

It will work once every hour, exactly at x:00.

Keep in mind the format of crontab is:

 +---------------- minute (0 - 59)
 |  +------------- hour (0 - 23)
 |  |  +---------- day of month (1 - 31)
 |  |  |  +------- month (1 - 12)
 |  |  |  |  +---- day of week (0 - 6) (Sunday=0 or 7)
 |  |  |  |  |
 *  *  *  *  *  command to be executed

so 0 in the first position means every minute 0, any hour, and day.