Calculating Number of Working Days between two dates

Declare @StartDay datetime, @EndDay datetime
Set @StartDay='2013-01-01'
Set @EndDay='2013-05-31'

;with cte(Date) as 
(
select @StartDay
union all
select Date+1 from cte where Date < @EndDay
)
select DATENAME(M,Date)Months,count(Date)[No Of Working Days] from cte 
where DATENAME(W,Date) not in ('sunday','saturday')
group by DATENAME(M,Date) option (MAXRECURSION 400)