Reference: Cron syntax

A quick reference to cron syntax follows. You can use Crontab to build a cron expression.

 ┌──────────── minute
 │ ┌────────── hour
 │ │ ┌──────── day of month
 │ │ │ ┌────── month
 │ │ │ │ ┌──── day of week
 │ │ │ │ │
 │ │ │ │ │
 * * * * *

Each asterisk is a field that must be included in the cron expression. The field value can either be an asterisk (any value) or one of the following values:

Valid values for cron fields

Field	Value
minute	0-59
hour	0-23
day of month	1-31
month	1-12
day of week (Sunday is 0 and 7)	0-7