Time Marker に in Japanese

Overview

The particle に (ni) has many uses in Japanese, and one of its most fundamental roles is marking specific points in time. When you say "at 7 o'clock," "on Monday," or "in March," the に particle is what connects the time word to the rest of the sentence.

This is an A1 concept that you will use every day. The key challenge is learning which time words take に and which do not. The rule is logical once you understand it: specific, absolute time points require に, while relative time words and frequency expressions do not.

How It Works

Time words that take に

Category	Examples	With に
Clock time	七時 (shichiji, 7 o'clock)	七時に
Days of the week	月曜日 (getsuyoubi, Monday)	月曜日に
Dates	三日 (mikka, the 3rd)	三日に
Months	三月 (sangatsu, March)	三月に
Years	2020年 (nisennijuunen)	2020年に
Specific occasions	誕生日 (tanjoubi, birthday)	誕生日に

Time words that do NOT take に

Category	Examples	Usage
Relative time	今日 (kyou, today), 明日 (ashita, tomorrow), 昨日 (kinou, yesterday)	No に
Frequency	毎日 (mainichi, every day), 毎週 (maishuu, every week)	No に
Vague time	朝 (asa, morning), 夜 (yoru, night) — when used generally	に is optional
This/last/next	今週 (konshuu, this week), 来月 (raigetsu, next month)	No に

The rule of thumb

If you can point to it on a calendar or clock (a specific, absolute time), use に. If it is relative to "now" (today, tomorrow, this week) or a frequency (every day), do not use に.

Examples in Context

Japanese	English	Note
七時に起きます。(shichiji ni okimasu.)	I wake up at 7 o'clock.	Clock time with に
月曜日に会いましょう。(getsuyoubi ni aimashou.)	Let's meet on Monday.	Day of week with に
三月に日本に行きます。(sangatsu ni nihon ni ikimasu.)	I'm going to Japan in March.	Month with に
2020年に生まれました。(nisennijuunen ni umaremashita.)	I was born in 2020.	Year with に
誕生日に何がほしいですか？(tanjoubi ni nani ga hoshii desu ka?)	What do you want for your birthday?	Specific occasion with に
今日、映画を見ます。(kyou, eiga o mimasu.)	I'm watching a movie today.	Relative time, no に
毎日コーヒーを飲みます。(mainichi koohii o nomimasu.)	I drink coffee every day.	Frequency, no に
来週テストがあります。(raishuu tesuto ga arimasu.)	There's a test next week.	Relative time, no に
十二月二十五日にクリスマスがあります。(juunigatsu nijuugonichi ni kurisumasu ga arimasu.)	Christmas is on December 25th.	Full date with に
朝六時に出発します。(asa rokuji ni shuppatsu shimasu.)	I depart at 6 a.m.	朝 is context; 六時 takes に

Common Mistakes

Adding に to relative time words

• Wrong: 今日に学校に行きます。
• Right: 今日、学校に行きます。
• Why: 今日 is relative time (it changes meaning depending on when you say it). No に needed.

Forgetting に with clock time

• Wrong: 三時帰ります。
• Right: 三時に帰ります。
• Why: Clock times are specific and absolute. They need に.

Adding に to 毎日/毎週

• Wrong: 毎日に勉強します。
• Right: 毎日勉強します。
• Why: Frequency words like 毎日 (every day) do not take に because they express repetition, not a specific point in time.

Practice Tips

• Write out your weekly schedule in Japanese, using に for days and times. Check each time word against the rule: is it specific/absolute or relative/frequency?
• When you learn a new time word, immediately categorize it: does it take に or not? This builds the habit of thinking about the distinction.
• Practice asking and answering questions like 何時に起きますか？ (What time do you wake up?) and 何曜日に日本語を勉強しますか？ (What day do you study Japanese?).

Related Concepts

• Prerequisite: Basic Particles は/が/を/に — the broader uses of に beyond time