Heh... None of the rest of us has ever done such a thing before.  😉

You're a good man, Jason.  Staying up late to help others even in the face of real work.  And then, doing the ultimate and admitting that a mistake has been made.  You can't ask for more than that.  My hat's off to you, good Sir.

On that note, I've made a function that I've used against the test data created by the generator that I posted just a bit back.  I resurrected an old Calendar table that I made for such a task with a "Business Day Number" and it's clocking in at about 1.3 seconds for a million rows of test data over the 2000 thru 2029 period as you've been testing for..  I don't want to post it yet because I'm double checking some of the edge cases and because there's a piece of code that I've been playing with that has the potential of 0.3 seconds, but I've not worked out the bugs yet.  Not sure I can.