Step 1: Go to "Uknowva configuration".
Step 2: In left hand side menu click on "Apps manager".
Step 3: Then search for "HRM Lite", pop up will appear.
Step 4: Scroll down to field "Non Working days" and click on "green +" button and change below settings:
1) Select Day of week -> "Saturday"
2) Days in the month -> 1,3 and save it.
Thanks.