Query to get No.Of specific Week days between two dates

The below query gives number of specific week days between two dates , the two dates can be in any order.

EX: Let us try to get number of Saturdays between two given dates.

 Declare @date1 datetime='20 aug 2013' ,

@date2 datetime='31 aug 2013'

 

select CASE when [PlanendDate]> [ActualEndDate] then (DATEDIFF(Day ,[ActualEndDate],[PlanendDate])/7)+1

                when [PlanendDate]< [ActualEndDate] then (DATEDIFF(Day ,[PlanendDate],[ActualEndDate])/7)+ CASE when datepart(dw,@date2)=7 then 1 else 0 end

                else 1

                end

               

                from (

select   case

                when datepart(dw,@date1)=7

                        then @date1

                else @date1+7-datepart(dw,@date1)

        end [PlanendDate],case

                when datepart(dw,@date2)=7

                        then @date2

                else @date2+7-datepart(dw,@date2)

        end [ActualEndDate]) A