And to be more specific: Even if you happen to be on a flight that only exists once a week (or, say 3x weekly), you won't get into trouble if it's cancelled and you find yourself a few days extra in China - in such cases, obviously, you'll have to talk with authorities, but as long as everything was fine when you entered China under TWOV, and whatever went wrong was outside of your responsibility, you don't have to worry about it.