Japanese time expressions follow a useful distinction: a specific time point often takes に, while relative words such as 今日, 明日, 昨日, and 毎日 normally do not. Japanese also separates a clock time such as 二時 “two o’clock” from a duration such as 二時間 “two hours.” Once those two distinctions are clear, schedules and past or future plans become much easier to express.
Core relative time words
| Time unit | Previous | Current | Next |
|---|---|---|---|
| Day | 昨日（きのう） | 今日（きょう） | 明日（あした／あす） |
| Morning | 昨日の朝 | 今朝（けさ） | 明日の朝 |
| Week | 先週（せんしゅう） | 今週（こんしゅう） | 来週（らいしゅう） |
| Month | 先月（せんげつ） | 今月（こんげつ） | 来月（らいげつ） |
| Year | 去年（きょねん） | 今年（ことし） | 来年（らいねん） |
These words are complete time adverbs and normally appear without に.
昨日、日本語を勉強しました。／I studied Japanese yesterday.
今日、図書館へ行きます。／I am going to the library today.
来週、試験があります。／There is a test next week.
昨日に, 今日に, and 来週に are not the normal beginner patterns. A longer expression may add another relationship, but start with these common forms without に.
The Japanese non-past covers habits and future plans
毎日、七時に起きます。／I get up at seven every day.
明日、七時に起きます。／I will get up at seven tomorrow.
The verb 起きます is the same. 毎日 gives it a habitual reading; 明日 gives it a future reading. Japanese does not need a separate equivalent of English will when the time expression already makes the future clear.
Telling the hour
| Time | Japanese | Reading |
|---|---|---|
| 1:00 | 一時 | いちじ |
| 4:00 | 四時 | よじ |
| 7:00 | 七時 | しちじ |
| 9:00 | 九時 | くじ |
| 12:00 | 十二時 | じゅうにじ |
Four, seven, and nine require attention: よじ, しちじ, and くじ. “What time?” is 何時（なんじ）.
今、何時ですか。― 四時です。
会議は何時に始まりますか。― 九時に始まります。
In the first exchange, time is the noun predicate: 四時です. In the second, 九時 marks the time at which the action begins, so it takes に.
Minutes and common sound changes
| Minute | Reading | Minute | Reading |
|---|---|---|---|
| 1分 | いっぷん | 6分 | ろっぷん |
| 2分 | にふん | 7分 | ななふん |
| 3分 | さんぷん | 8分 | はっぷん |
| 4分 | よんぷん | 9分 | きゅうふん |
| 5分 | ごふん | 10分 | じゅっぷん／じっぷん |
Half past is 半（はん）: 七時半 is 7:30. “What minute?” or “how many minutes?” is 何分（なんぷん）; context tells whether it asks a position on the clock or a duration.
電車は六時十五分に出ます。／The train leaves at 6:15.
授業は九時半からです。／Class starts at 9:30.
When to use に
Use に with a specific point at which an event occurs: clock times, many dates, and commonly days of the week.
六時半に起きます。
月曜日に会議があります。
七月二十日に日本へ行きます。
二〇二七年に卒業します。
Days of the week may omit に in casual schedule statements, but 月曜日に is a clear beginner form. Do not add に after 毎日, 今日, 明日, 昨日, 今週, or 去年 in ordinary sentences.
A time point is not a duration
| Point | Duration | Meaning |
|---|---|---|
| 二時 | 二時間 | 2:00 / two hours |
| 三日（みっか） | 三日間（みっかかん） | the third day or three days / for three days |
| 一週間 | 一週間 | a week-long period; context supplies the role |
二時に勉強します。／I study at two.
二時間勉強します。／I study for two hours.
日本に三年間住みました。／I lived in Japan for three years.
A duration normally does not take に. 二時間に勉強します does not mean “study for two hours.” Add 間 when it helps make the duration explicit, especially with longer units, but many common duration expressions can omit it.
From and until: から and まで
授業は九時から十二時までです。／Class is from nine until twelve.
月曜日から金曜日まで働きます。／I work from Monday to Friday.
去年から日本語を勉強しています。／I have been studying Japanese since last year.
から marks the starting boundary; まで marks the ending boundary. Either can appear alone: 五時まで働きます “I work until five.” With time boundaries, you do not need に as well: 九時から is sufficient.
Before and after
授業の前に、宿題をします。／I do homework before class.
仕事の後で、友達と会います。／I meet a friend after work.
寝る前に、本を読みます。／I read before going to bed.
ご飯を食べた後で、散歩します。／I take a walk after eating.
Before a noun, use noun＋の前に／の後で. Before a verb, 前に takes the non-past plain form even when the whole sentence is past: 寝る前に. 後で commonly follows the past plain form because the first action is completed: 食べた後で.
Frequency and intervals
毎朝コーヒーを飲みます。／I drink coffee every morning.
一週間に三回運動します。／I exercise three times a week.
一日に八時間働きます。／I work eight hours a day.
ときどき映画を見ます。／I sometimes watch films.
The frame 一週間に means “within one week,” and 三回 is the frequency. Do not confuse the number of repetitions with duration: 三回 is three times; 三時間 is three hours.
Put time expressions in a readable order
A broad-to-specific order is often natural: day, clock time, place, object, verb.
明日の朝、七時半に家で朝ご飯を食べます。
Tomorrow morning, I will eat breakfast at home at 7:30.
来週の月曜日、午後二時に会社で会議があります。
Next Monday, there is a meeting at the office at 2 p.m.
Particles make some reordering possible, but a stable order helps listeners process the schedule. 午前 and 午後 come before the clock time: 午前九時, 午後三時半.
A daily schedule model
平日は六時半に起きます。七時から七時半まで朝ご飯を食べて、ニュースを見ます。八時に家を出ます。九時から五時まで働きます。仕事の後で、一時間日本語を勉強します。十一時ごろ寝ます。
On weekdays I get up at 6:30. From seven to 7:30, I eat breakfast and watch the news. I leave home at eight. I work from nine to five. After work, I study Japanese for an hour. I go to bed at about eleven.
ごろ means “around” a time. Do not normally add に after a time followed by ごろ in this pattern: 十一時ごろ寝ます is natural.
Common mistakes
- Adding に after every time word: 明日に行きます instead of 明日、行きます.
- Reading 四時 as よんじ instead of よじ.
- Confusing 二時 with 二時間.
- Adding に to a duration: 二時間に勉強します.
- Using non-past for a finished event with 昨日: 昨日行きます instead of 昨日行きました.
- Using から and に together for the same boundary: 九時にから.
- Putting 午後 after the hour instead of before it.
Practice
- Say “I will go tomorrow” without using に.
- Read 4:00, 7:00, 9:00, and 7:30.
- Translate: “I study at two” and “I study for two hours.”
- Say “Class is from nine to twelve.”
- Choose: 毎日（に／—）日本語を勉強します.
- Say “I exercise three times a week.”
- Say “I read before sleeping.”
- Correct: 昨日、三時に友達と会います.
Answers: 1 明日、行きます. 2 よじ、しちじ、くじ、しちじはん. 3 二時に勉強します／二時間勉強します. 4 授業は九時から十二時までです. 5 毎日、日本語を勉強します. 6 一週間に三回運動します. 7 寝る前に、本を読みます. 8 昨日、三時に友達と会いました.
Quick rule: when does a Japanese time word take に?
Use に with a specific scheduled point such as 七時に or 月曜日に. Normally omit it after relative time words such as 今日, 明日, 昨日, 今週, and 毎日. Also keep clock time and duration separate: 二時 means “two o’clock,” while 二時間 means “two hours.”
Japanese particles を, に, and でJapanese counters for beginners
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