Count total working days between two days in T-SQL

Create a user defined scalar function:

CREATE FUNCTION [dbo].[udf_GetWorkingDays](@StartDate DATETIME,@EndDate DATETIME)

RETURNS INT

AS

BEGIN

DECLARE @CurDate DATETIME

DECLARE @i INT

DECLARE @days INT

set @i=1

set @days=0

while @i<=(DATEDIFF(dd, @StartDate, @EndDate))

begin

      set @CurDate=dateadd(day,@i, @StartDate)

      if(DATENAME(dw, @CurDate) != 'Friday' and DATENAME(dw, @CurDate) != 'Saturday')

      begin

            set @days=@days+1

      end

      set @i=@i+1

end

RETURN @days

END

Let's test now with following query:
 

select dbo.udf_GetWorkingDays('01/01/2011','01/31/2011') as TotalWorkingDays

 Result is: 22

Hope this will help others.