You can go to class if you have classes, and then volunteer to participate in activities. There are basically no other restrictions. Therefore, in Zhejiang University, you may only have evening self-study when you are a freshman, and some majors are freshmen, and then other professional universities don't have it for four years. So this is the situation of Zhejiang University's evening self-study.
Moreover, there is a phenomenon that the better the university, the less there will be such a provision for self-study at night.
Refer to the above contents: General situation of Zhejiang University