に (time)

• Reading: に
• Romaji: ni
• Formation: Specific time expression + に + Verb

Meaning

A particle that marks a specific point in time at which something takes place. It is used with concrete time expressions such as days, dates, months, and clock times.

に is used to pin an event to a specific, countable time. It works with clock times (三時に), days of the week (月曜日に), dates (一月五日に), months (四月に), and years (二〇二五年に). However, に is NOT used with relative time words like 今日, 明日, 昨日, 毎日, 来週, or 去年 because these are already specific without a marker. It is also not used with ～とき in most cases. A useful rule: if you can put a number on the time, use に; if not, omit it. This is one of the most frequently tested particles in Japanese proficiency exams.

Examples

1. 六時に起きます。 I wake up at six o'clock.
2. 土曜日に映画を見に行きましょう。 Let's go see a movie on Saturday.
3. 三月に日本へ行く予定です。 I plan to go to Japan in March.

Usage Guide

Context: spoken, written, everyday

Tone: descriptive

Do Say

• 会議は十時に始まります。
• 水曜日に歯医者に行きます。
• 二〇二〇年に引っ越しました。

Don't Say

• 昨日にたくさん食べました。(に is not used with relative time words like 昨日) → 昨日たくさん食べました。
• 毎朝に散歩をします。(に is not used with 毎～ expressions) → 毎朝散歩をします。
• 来週にテストがあります。(に is not needed with 来週, a relative time expression) → 来週テストがあります。

Origin & History

に as a time marker derives from its fundamental locational meaning — just as に places something in physical space, it also places events at points in time. This spatial-temporal parallel exists in many world languages.

Cultural Context

Generation: All ages

Social background: Universal