Mikeyd,
With only newspaper reports and what I've read here to rely on, I can't claim any reliable knowledge of the subject, so please tell me if I'm barking up the wrong tree. You say that fire fighters cannot work on their last day before duty, yet I'm sure I've read about some having day jobs while they're on nights. Obviously that would be against the rules you mentioned, and would prevent getting a good day's rest before the night shift, but does that mean it doesn't happen?
BCH