“值日”是说在某一天里轮到你做一些工作，比如在学校打扫教室、擦黑板。

"值日" means it's your turn to do some tasks on a certain day, like cleaning the classroom or wiping the blackboard at school.

每个同学都要轮流值日，所以今天可能是你，明天是别人。

Every student takes turns doing 值日, so today might be you, and tomorrow someone else.