How many weekdays are there in a given YEAR, MONTH ?

Declare @Year Int, @Month Int

Select @Year = 2012
Select @Month = 2

;With CTEs
As
(
Select 0 Slno
Union All
Select Slno + 1  From CTEs Where Slno <=30
),
[Days]
As
(
Select DateName(Weekday,DATEADD(Day,Slno,Cast(@Year as varchar)+ '-' + Cast(@Month as varchar) + '-01')) [Day], DATEADD(Day,Slno,Cast(@Year as varchar)+ '-' + Cast(@Month as varchar) + '-01') [Date] From CTEs
)

select [Day], COUNT(1) [Days] from [Days] Where Month([Date]) =@Month
Group by [Day]

Day	Days
----    ----- 
Friday	4
Monday	4
Saturday	4
Sunday	4
Thursday	4
Tuesday	4
Wednesday	5