Working Days in T-SQL

These two posts helped greatly in getting a function to work out the working days between two working days:
http://aaronjohals.blogspot.com/2005/10/number-of-working-days-between-2-dates.html
http://classicasp.aspfaq.com/date-time-routines-manipulation/how-do-i-count-the-number-of-business-days-between-two-dates.html

drop function dbo.GetWorkingDaysDiff

go

create function dbo.GetWorkingDaysDiff(@start datetime, @end datetime)

    returns int

as 

begin

    declare @countdays int

    set @countdays = 0

    while @start < @end

    begin

        if (select datepart(dw, @start)) < 6

        begin

            set @countdays = @countdays + 1

        end

        set @start = dateadd(d,1,@start)

    end

    return @countdays

end 

GO

print(dbo.GetWorkingDaysDiff('2006/08/21', '2006/08/27'))

go