Great question perfectly worded. It was quite clear that dateformat was relevant to the question and that you were looking for only the 2 statements that would work under all conditions. I hate the pedantics on here.
However, without 2008 to play on, and after much unsuccessful digging around with google, I ended up guessing wrong. Bummer!
Learned something new though, which is always the primary objective :-)
Keep them coming Duncan.
"The difficult tasks we do immediately, the impossible takes a little longer"