I want to do it because we have one weekend of study leave (really helpful, no?) but unfortunately it is vital I'm in school for my Italian lessons.
What I'm really struggling with at the moment is writing all these essays my teachers want me to do (I do mostly essay subjects) and revising at the same time! I had a really terrible weekend sleep-wise, so I didn't get any homework done so I'm doing it now so I have no time to revise otherwise!
If you have a day where you're sure you have no lessons where you'll be learning anything new, take the day off. Your school will know you're not actually ill, but they're not going to do anything. Tonnes of people are suddenly ill at my school :P