ATG Calendar Scheduler interesting

Today I am going to explain very interesting point about ATG schedulers.

To configure the scheduler in ATG we need to assign value to schedule property of the scheduler.
 There are 3 types of formats for this property.

1. Relative Schedule.
2. Periodic Schedule.
3. Calendar Schedule.

Out of above mentioned formats Calendar Schedule is most confusing.Here is the syntax for Calendar Schedule.

Syntax : calendar <months> <dates> <days of week>  <occurrences in month> <hours> <minutes>

Example schedule 

calendar * * 1 * 22 0

Here the * in date field will invoke this scheduler every day. 

Thumb rule is

A * entry selects all values for that field. A period (.) selects no values.

calendar * . 1 * 22 0

Above scheduler will run weekly.