Scenario:
I have an user who takes repeated leaves on Monday or I want to find the specific day of the week when an user takes most of the leaves, the solution provided below can be used.

Resolution:
Use the Time Off Details Report and in the same report use the field – Day Of Week (Time Off Date). This field will provide you the Day of the Week in which an user has taken a Time Off. Using this report you can determine how many times an user has taken a leave on Monday for a specific span of time.