Looks like a considerate enough letter issued in advance, and with clear guidance as to what will happen.

Dragonized: What do you mean 'Wow"? A national holiday coincides with your work schedule and you get an extra days pay....that's standard in any country from my experience. Could you explain what the breach of labour law is exactly as you have alluded to?

Magister: It's a well known and regular holiday, so if you choose to teach in China I assume you would take the time to familiarise yourself with local holidays/customs etc, therefore this is standard. Whether a student that usually comes once a week to the class attends on the weekend as normal, or as is the case here, on a weekday, I fail to see how this is not 'conducive' to a good teaching environment?