it's good to have such a big lunch time!

I'm having another problem, when i make

select dbo.CalcTimeSinceCreated(convert(datetime,'31-12-2007',105),convert(datetime,'02-01-2008',105))

And i've an holiday in my database for the date (01-01-2008),

it goes to a infinite cicle.

but when i make

select dbo.CalcTimeSinceCreated(convert(datetime,'31-12-2007',105),convert(datetime,'03-01-2008',105))

all works fine! do you know why?