Hi Sudhakar ,
Try this :
=SUM(IF(WEEKDAY(ROW(INDIRECT(Start Date&":"&End Date)))=1,1,0))
which is to be entered as an array formula , using CTRL SHIFT ENTER.
Start Date is a reference to your cell which has the start date , say A1. End Date is a reference to the cell which has the end date , say A2.
Sunday has a day number of 1 , hence the check for equality to 1. If you want to check for the number of Saturdays , the number should be changed to 7 , as follows :
=SUM(IF(WEEKDAY(ROW(INDIRECT(Start Date&":"&End Date)))=7,1,0))
If you want the End Date always to be the end of the month , you can replace the End Date in the above formula , by the function EOMONTH(Start Date,0) ; to use this function , you will have to have the Analysis Toolpak add-in installed.
Narayan