不要
在this, that, next, last, every, yesterday, tomorrow等构成的时间状语前不加任何介词.
（last year, this month, next week, last Saturday, every day, yesterday afternoon, tomorrow morning）
[误]We're going to study harder in this term.
[正] We're going to study harder this term.
[误] I'll be free on next Sunday.
[正] I'll be free next Sunday