Count work days between two dates

Question

How can I calculate the number of work days between two dates in SQL Server?

Monday to Friday and it must be T-SQL.

Answer 1

(I'm a few points shy of commenting privileges)

If you decide to forgo the +1 day in CMS's elegant solution, note that if your start date and end date are in the same weekend, you get a negative answer. Ie., 2008/10/26 to 2008/10/26 returns -1.

my rather simplistic solution:

select @Result = (..CMS's answer..)
if  (@Result < 0)
        select @Result = 0
    RETURN @Result

.. which also sets all erroneous posts with start date after end date to zero. Something you may or may not be looking for.