Most TCs will actually despite the lack of the long summer/winter vacation, at least follow general Chinese employment law and give you all public holidays off or a standard rate of overtime pay (usually triple). Most have the sense not to remain open on such days as they get no customers coming to class anyway.

The main problem that is caused with TCs and public holidays is that the public schools in china insist on 'making up' classes that are missed as the result of the holiday (it begs the question why have the holiday in the first place?). These made up classes generally happen at the weekend, which is when TCs do most of their business so the TC is required to cancel classes at the weekend because most students will be at public school. Even the baboons that run most TCs understand the basic principle that you need to keep course production high in order to turn a profit so they will usually reschedule the weekend classes during the middle of the week when the students are off - the short holidays are usually 3 days with 1 day being the actual festival/official holiday which they usually choose to avoid scheduling classes on but they'll view the other 2 days as fair game and they certainly won't pay overtime for you working during them. From what I've seen of TC contracts they usually only pay overtime when you exceed your contracted hours and even then that is usually only calculated on a weekly average over the month, meaning you might get screwed with high hours one week as a result of them shuffling classes around due to public holidays but so long as they can get the average down over the rest of the month you won't be paid any extra. The other issue is when they decide to make you work during a public holiday and then give you a day in lieu. The day on which the holiday is taken is then usually decided by the employer and not the employee and you shouldn't be surprised to find that it'll be a day when the school is quiet - again course production overrides the needs and wants of teachers and in some cases the law itself (whatever that might mean in china)

I totally agree that employers should explain these differences to prospective employees before they arrive in China. Most westerners will arrive here with the idea that a holiday is a holiday and doesn't require making up the time lost at an earlier/later date - this issue causes friction between foreign teachers and Chinese employers involved in both public and private education in china.