What is the concept multiple workday patterns allowed to add at work schedule level in absence level

Dear Experts,

I want to understand the concept of adding multiple work day pattern at work schedule level in fusion hcm?

if we think like , these two pattern will work for as per sequence number wise 1, 2 what about efeective start date and efeective end date ? these dates are same for both patterns.

Can anybody explain the concept, i wold appriciate your support.

Thank you

Ravindra