DQ4 -
Just to prevent my imminent heart attack, please confirm: The way it is at present is that if you fly into the UK on say Monday afternoon and depart 24 hours later on say Tuesday, the fact that you were in the UK for one night means that you must count that as one day in the UK. You were not in the UK on Tuesday night therefore you don't count that as a day there.
That's how it is at the moment isn't it?