I hope they would get a substitute they are the one's paying for the education not the teacher. It would be really stupid if the teacher asked for a day off it got granted and then they canceled the class...

For me, they usuallly cancel the class and I need to make  up the class later (often on a saturday)(. However, it is 50/50 that they will acrtually folllow up on it  if it is just one day.

When I was at a key school, they'd bring in a teacher who wasn't busy for a reading period or some such thing. Like Guilin, they would say they were rescheduling it, but that was more of a threat to keep me from taking too many sick days.

Which is a lot better than a training centre, where, no matter what the contract says, you wont get a sick day if you die.

They get one of the part timers to cover for them or load the rest of the full timers with extra classes.

Depends how you mean 'day off'... where I've worked (universities), it's been required that you make it up some other time - dead of alive!

Usually they will grant you the day off without pay and in some cases they have tried to charge me for the part time teacher that they had to bring in.