Hi,
In this perspective, it is clearly understood that the employees and HR department do not have a clear policy about the notice period. As soon as the employees submit their resignation, after acceptance, their notice period starts. The notice period is nothing but the obligation of the employee to fulfill their duties to complete the other formalities. During this period, holidays and weekly off days are naturally calculated and included in the notice period. Even employees can work on holidays and complete their remaining tasks.
Holidays and weekly offs are privileges given by labor law, and employers cannot curtail them.