I think the most consistent day off here is Sunday.
Lots and lots of folks working 6-day weeks here.
Lots and lots of folks working
7-day weeks here...
For many Chinese people, employers hold them in near-servitude. Documents are kept on file that people need to get a job. If the employee causes a problem, or the employer doesn't want them to move on, these documents are simply held. Employers have veto power over marriages, having children...all kinds of "personal" decisions. Add that to the fact that for every job here there's a big pile of people hoping to get it, and you get an extremely ugly employment picture.
So: Work all weekend, too? No extra pay? Yes, sir! Thank you, sir!