school night
noun [ C ] uk/ˈskuːl ˌnaɪt/ us/ˈskuːl ˌnaɪt/
（儿童）上学前一天的晚上;（成人）上班前一天的晚上
the evening before a day when children have to go to school. Adults also use this expression informally to describe the evening before a day when they have to get up to go to work.
I don't usually stay out this late on a school night. 明天要上班，我一般不会这么晚还不回家。