There are no classes. Universities are a kind of schools that implement higher education, including comprehensive universities, specialized universities and colleges. It is an organization with unique functions, an institution of higher learning that inherits, studies, integrates and innovates advanced academic knowledge, and is interrelated with social, economic and political institutions. Under normal circumstances, there is no Saturday and Sunday class arrangement in universities, because the class time of full-time universities is from Monday to Friday, and Saturday and Sunday are reserved for students to do their own things. But sometimes, some schools have a lot of specialized courses, and they may arrange classes on Saturday and Sunday, or take a long vacation and move classes to Saturday and Sunday. Strictly speaking, most college students don't need to attend classes on Saturday and Sunday.