A while ago a lady in the UK informed me that Americans don't get days off work for being ill, they have to take it unpaid. However, they get several days a year that are "personal" day that they don't need a reason to take off. Since then, I've found out that's not strictly true, but in essence it's correct.
This girl tried it on her manager and she got away with it, a thing that i put down to her manager being not entirely up to speed with the UK regs and her being a stubborn American.
So... do you think you could get away with it? Asking for a personal day? Taking a day off without having to give a reason for it?