In reply to toasted: You're better off asking for the day off, find a compromise if necessary. Your boss will notice that you're pulling a sickie the day before you're due to be off, trust me. As someone else said, there will be options, swap shifts with somebody else, offer to work an extra shift the week after or so on. If you can't afford to get sacked, don't take the p*ss. I'll do my best for my staff if they need a day off for a legitimate reason, I'll even cover the shift myself if needs be, try to play games or think you're being a crafty devil and I'll give the work to a responsible team player instead.