HI Kapil,
You can use the FM "DAY_IN_WEEK", in order to get what you want.
This FM convert your date into the day in the week and returns :
Monday -> 1
Tuesday -> 2
Wednesday -> 3
Thursday -> 4
Friday -> 5
Saturday -> 6
Sunday -> 7
So if the returns value is 6 or 7 => This is the weekend.
Hope that will help you.
Regards,
Sam,