Time: when something happens

Clock times: number + じ, minutes with ふん, half past with はん: ろくじはん. Weekdays end in ようび: にちようび, Sunday. The days around today: きのう, きょう, あした. And まいにち, every day.

When something happens, the time stands before the verb. Clock times and weekdays take に: くじに はじまります, にちようびに いきます. Words for days and habits take no particle: きょう いきます, あした かえります, まいにち たべます. The rule: an exact time or a named day — に; a word counted from today or saying how often — no particle.

An interval spans from … to with から…まで: くじから さんじまで, from nine to three. The same pair works for places. いつ asks when: いつ かえりますか. You ask the time with なんじ and the day with なんようび.

Order: the time comes early in the sentence, usually right after the topic: わたしは あした がっこうへ いきます.