Significance of approval period in the time and labor

Content

We have a condition in the time and labor that time card period and approval period should be having same frequency(Repeating Period). But the timecard can be approved any time irrespective of the approval period. Let us say approval period is weekly starting Sunday(03-Feb-2019-to-09-Feb-2019) and the time card can be approved any day even outside the mentioned period. Unable to understand the significance of the approval period here.

Can someone please help me understand the significance of the approval period.

Thanks in advance.