Telling time in Japanese uses two counters stacked together: 〜時（じ） for the hour ("o'clock") and 〜分（ふん／ぷん） for the minutes, with 半（はん） as a handy shortcut for "half past." Neither counter is fully regular. 時 has three irregular hour-readings you'll use constantly, and 分 has more sound changes than almost any counter in the language — which is exactly why it's the perfect place to drill the geminate-and-voicing rule until it's automatic.
The hours: 〜時
Take a Sino number and add 〜じ. Three of the twelve are irregular, and they are the three you must nail.
| Hour | Reading | Hour | Reading |
|---|---|---|---|
| 1時 | いちじ (ichi-ji) | 7時 | しちじ (shichi-ji) |
| 2時 | にじ (ni-ji) | 8時 | はちじ (hachi-ji) |
| 3時 | さんじ (san-ji) | 9時 | くじ (ku-ji) |
| 4時 | よじ (yo-ji) | 10時 | じゅうじ (jū-ji) |
| 5時 | ごじ (go-ji) | 11時 | じゅういちじ (jū-ichi-ji) |
| 6時 | ろくじ (roku-ji) | 12時 | じゅうにじ (jū-ni-ji) |
The three to burn in:
- 4時 = よじ — uses よ, not the usual よん and definitely not し. Never shi-ji, never yon-ji.
- 7時 = しちじ — uses しち, not なな. So shichi-ji, not nana-ji.
- 9時 = くじ — uses く, not きゅう. So ku-ji, not kyū-ji.
"What time?" is 何時（なんじ） nan-ji.
お店は九時に開きます。
omise wa ku-ji ni akimasu
The shop opens at nine.
今何時？もう寝る時間だよ。
ima nan-ji? mō neru jikan da yo
What time is it? It's already bedtime.
毎朝七時に起きています。
maiasa shichi-ji ni okite imasu
I get up at seven every morning.
The minutes: 〜分
Now the workhorse. 分 begins with an h-type sound, so it is a magnet for both euphonic forces — gemination (a held っ + a hardened ぷ) after 1, 6, 8, 10, and voicing-to-p after ん (3, 何). The result is an alternation between soft ふん and hard ぷん that runs the whole way up.
| Min. | Reading | Min. | Reading |
|---|---|---|---|
| 1分 | いっぷん (ippun) | 6分 | ろっぷん (roppun) |
| 2分 | にふん (ni-fun) | 7分 | ななふん (nana-fun) |
| 3分 | さんぷん (sanpun) | 8分 | はっぷん (happun) |
| 4分 | よんぷん (yonpun) | 9分 | きゅうふん (kyū-fun) |
| 5分 | ごふん (go-fun) | 10分 | じゅっぷん (juppun) |
Read the pattern, don't memorize twelve isolated words. ぷん (hard p) appears after 1, 3, 4, 6, 8, 10 and 何 (何分 nanpun); ふん (soft f) stays after the "quiet" numbers 2, 5, 7, 9. That split is the two forces in miniature:
- 1, 6, 8, 10 geminate: a small っ appears and f hardens to p → いっぷん, ろっぷん, はっぷん, じゅっぷん.
- 3, 何 end in ん, which voices/hardens the following f to p → さんぷん, なんぷん.
- 4 is the surprise: normally a "quiet" number, but 分 is greedy and takes ぷん here too → よんぷん.
- Tens follow the ones: 15分 じゅうごふん (jū-go-fun), 30分 さんじゅっぷん (san-juppun), 45分 よんじゅうごふん (yon-jū-go-fun).
あと一分で電車が来るよ、急いで！
ato ippun de densha ga kuru yo, isoide!
The train comes in one minute — hurry!
レンジで三分だけ温めてね。
renji de sanpun dake atatamete ne
Just heat it in the microwave for three minutes.
十分ほど遅れそう、ごめん。
juppun hodo okuresō, gomen
Looks like I'll be about ten minutes late, sorry.
The full logic behind this alternation — and the fact that 分 is the counter most linguists reach for to illustrate it — lives on Counter Sound Changes: The Master Pattern. If you can conjugate 分 cold, most other counters will feel easy.
Putting hours and minutes together — and 半 for half past
To give a full time, just say the hour, then the minutes: hour + 時 + minutes + 分. No word for "and," no "past," no "o'clock" filler — Japanese states it in one clean stream.
電車は七時十五分に出ます。
densha wa shichi-ji jū-go-fun ni demasu
The train leaves at 7:15.
会議は十時二十五分から始まります。
kaigi wa jū-ji ni-jū-go-fun kara hajimarimasu
The meeting starts at 10:25.
For the very common "half past," you don't say 三十分 — you use 半（はん） han, tacked straight onto the hour:
四時半にそっちに着くと思う。
yo-ji-han ni sotchi ni tsuku to omou
I think I'll get to you around half past four.
お昼は十二時半に食べよう。
ohiru wa jū-ni-ji-han ni tabeyō
Let's have lunch at half past twelve.
For morning and afternoon, prefix 午前（ごぜん） "AM" or 午後（ごご） "PM" — Japan uses a 12-hour clock in speech even though timetables print 24-hour times.
打ち合わせは午後二時からでお願いします。
uchiawase wa gogo ni-ji kara de onegai shimasu
Let's make the meeting from 2 PM, please.
Time points take に
A clock time is a specific point in time, so it takes the particle に when it marks when something happens: 九時に, 四時半に, 七時十五分に. This is the same に used for dates (四日に) and weekdays (月曜日に) — see に: Specific Points in Time. Vague time words like 今 (ima, "now") or 朝 (asa, "morning") do not take に, but a number-on-the-clock always can.
六時に晩ご飯にしよう。
roku-ji ni bangohan ni shiyō
Let's have dinner at six.
時 (o'clock) vs 時間 (hours of duration)
Don't confuse the hour of the clock with a span of hours. 三時 san-ji is "3 o'clock" (a point); 三時間 san-jikan is "three hours" (a length). Add 間（かん）and you switch from telling time to measuring it — exactly parallel to how 三日 (a date) becomes 三日間 (a three-day span).
三時間も並んだのに、売り切れだった。
san-jikan mo naranda noni, urikire datta
I queued for three whole hours and it was sold out.
Common mistakes
❌ 四時 = しじ
Incorrect — 4 o'clock uses よ, not し.
✅ 四時 = よじ
yo-ji
four o'clock
Reading 四時 with the default shi is the classic error — and shi also sounds like 死 ("death"), which is a second reason Japanese avoids it. It's always よじ.
❌ 九時 = きゅうじ
Incorrect — 9 o'clock uses く, not きゅう.
✅ 九時 = くじ
ku-ji
nine o'clock
Since 9 is usually きゅう, learners produce kyū-ji. But the hour, the month (九月 くがつ), and the day (九日 ここのか) all favor く. Nine o'clock is くじ.
❌ 三分 = さんふん
Incorrect — after ん, 分 hardens to ぷん.
✅ 三分 = さんぷん
sanpun
three minutes
Leaving 分 as soft fun after 3 is the most common minutes error. The ん forces it to ぷん: さんぷん. The same hardening gives you いっぷん, ろっぷん, はっぷん, じゅっぷん.
❌ 一時半分に会おう。
Incorrect — 半 (half past) is not combined with 分. Say 一時半, not 一時半分.
✅ 一時半に会おう。
ichi-ji-han ni aō
Let's meet at half past one.
半 already means "thirty minutes past," so you never add 分 to it. It's simply 時 + 半.
Key takeaways
- Hours are number + 〜時, with three irregulars: 4時 よじ, 7時 しちじ, 9時 くじ (and 何時 なんじ for "what time").
- Minutes alternate ふん / ぷん: hard ぷん after 1, 3, 4, 6, 8, 10, 何; soft ふん after 2, 5, 7, 9 — the geminate-and-voicing rule in its purest form.
- Build a full time as hour + minutes; use 半（はん） for "half past" (四時半 = 4:30) and 午前／午後 for AM/PM.
- Clock times take に to mark when something happens (九時に).
- Keep 時 (o'clock, a point) apart from 時間 (hours, a duration): 三時 ≠ 三時間.
Now practice Japanese
Reading grammar gets you part of the way. The exercises are where it sticks — free, no signup needed.
Start learning Japanese→Related Topics
- Counting and Naming Days (日)N5 — The highly irregular 〜日 counter for calendar dates and day-counts — the native-root block ついたち〜とおか plus はつか, the single most irregular counter in Japanese.
- Counter Sound Changes: The Master PatternN4 — The two euphonic rules behind nearly all counter irregularity — gemination after 一/六/八/十 and voicing after 三/何 — laid out as one master grid across 本, 匹, 分, 階, 冊, and 杯.
- に: Specific Points in TimeN5 — When time expressions take に and when they don't — the absolute-vs-relative divide that decides why 七時に and 月曜日に need に but 今日, 明日, and 毎日 never do.