日/週/月/年

Date/period Counters

Level 1Sounds Like nichi/shuu/gatsu/nen

Japanese uses specific counters for time. The reading often changes depending on whether you are talking about a point in time (a date) or a duration (how long).

How It Works

Japanese time counters are divided into four main units: days, weeks, months, and years. Understanding the difference between a specific date and a length of time is crucial.

1. Days (日)
Dates have many irregular readings, especially for the 1st through the 10th, the 14th, 20th, and 24th.

  • Relative Time: Words for days include 一昨日（おととい - the day before yesterday）, 昨日（きのう - yesterday）, 今日（きょう - today）, 明日（あした - tomorrow）, and 明後日（あさって - the day after tomorrow）.
  • Date: For regular days, use Number + 日（にち）, such as 十一日（じゅういちにち） for the 11th and 十五日（じゅうごにち） for the 15th. However, there are many irregular readings: 1st is 一日（ついたち）, 2nd is 二日（ふつか）, 3rd is 三日（みっか）, 4th is 四日（よっか）, 5th is 五日（いつか）, 6th is 六日（むいか）, 7th is 七日（なのか）, 8th is 八日（ようか）, 9th is 九日（ここのか）, 10th is 十日（とおか）, 14th is 十四日（じゅうよっか）, 20th is 二十日（はつか）, and 24th is 二十四日（にじゅうよっか）.
  • Duration: 1 day is 一日（いちにち）. Note that for 'one day', we do not usually add 間（かん）. For 2 days onward, the word for the date and duration is exactly the same (e.g., 二日（ふつか） means both 'the 2nd' and 'two days'). Adding 間（かん） is optional to be clear, like 三日間（みっかかん） for '3 days'. Half a day is 半日（はんにち）.
  • Question: 何日（なんにち） (Which day? / How many days?)

2. Weeks (週)

  • Relative Time: Use 週（しゅう） for points in time, such as 先々週（せんせんしゅう - the week before last）, 先週（せんしゅう - last week）, 今週（こんしゅう - this week）, 来週（らいしゅう - next week）, and 再来週（さらいしゅう - the week after next）.
  • Duration: Use 週間（しゅうかん）. For example, 一週間（いっしゅうかん） means 'one week'.
  • Question: 第何週（だいなんしゅう） or 何週目（なんしゅうめ） (Which week?) and 何週間（なんしゅうかん） (How many weeks?). Note: To ask 'What day of the week?', use 何曜日（なんようび）, which is different from asking for the date or week.

3. Months (月)
There is a strict distinction here:

  • Relative Time: Words for months include 先々月（せんせんげつ - the month before last）, 先月（せんげつ - last month）, 今月（こんげつ - this month）, 来月（らいげつ - next month）, and 再来月（さらいげつ - the month after next）.
  • Point in Time (Month Name): Use 〜月（がつ）. January is 一月（いちがつ）, April is 四月（しがつ）, July is 七月（しちがつ）, and September is 九月（くがつ）.
  • Duration: Use 〜ヶ月（かげつ）. One month is 一ヶ月（いっかげつ）. Note that ヶ月 is frequently written as か月 or カ月. For 4, 7, and 9 months, the readings are 四ヶ月（よんかげつ）, 七ヶ月（ななかげつ / しちかげつ）, and 九ヶ月（きゅうかげつ）. Additionally, native Japanese counters are extremely common for one, two, and three months: 一月（ひとつき）, 二月（ふたつき）, and 三月（みつき）. Note that this native counting system stops at 3 or 4 months, and you must use 〜ヶ月 for durations of 5 months or longer. Half a month is 半月（はんつき）.
  • Question: 何月（なんがつ） (Which month?) or 何ヶ月（なんかげつ） (How many months?)

4. Years (年)
Years are mostly regular using 〜年（ねん）.

  • Relative Time: Words for years include 一昨年（おととし - the year before last）, 去年（きょねん - last year）, 今年（ことし - this year, highly irregular reading）, 来年（らいねん - next year）, and 再来年（さらいねん - the year after next）.
  • Irregular: 4 years is standardly read as 四年（よねん）, using the alternative reading よ before the counter. 7 years is 七年（しちねん / ななねん）. For 9 years, both 九年（くねん） and 九年（きゅうねん） can be used for either a point in time or a duration.
  • Duration: The suffix 間（かん） is optional (e.g., 三年 or 三年間 both mean 'three years'). Half a year is 半年（はんとし）.
  • Question: 何年（なんねん） (Which year? / How many years?) or 何年間（なんねんかん） (How many years?)

Examples (5)

  1. 誕生日（たんじょうび）は五月三日（ごがつみっか）です。

    My birthday is May 3rd.

    Word by Word: Birthday (topic) May 3rd is.

    Uses 〜月（がつ） for the month name and the irregular reading 三日（みっか） for the date.

  2. 日本（にほん）に二週間（にしゅうかん）いました。

    I was in Japan for two weeks.

    Word by Word: Japan in two weeks existed (polite).

    Uses 週間（しゅうかん） to express a duration of time.

  3. 三ヶ月（さんかげつ）ぐらい日本語（にほんご）を勉強（べんきょう）しました。

    I studied Japanese for about three months.

    Word by Word: Three months about Japanese (object) study did.

    Uses ヶ月（かげつ） for duration. Note that 'four months' would be 四ヶ月（よんかげつ）, not 四月（しがつ）.

  4. この仕事（しごと）は三年（さんねん）かかります。

    This job will take three years.

    Word by Word: This work (topic) three years takes.

    For years, 〜年（ねん） can be used for both the calendar year and the duration.

  5. 一日（いちにち）は二十四時間（にじゅうよじかん）です。

    One day is twenty-four hours.

    Word by Word: One day (topic) 24 hours is.

    Here, 一日 is read as いちにち because it refers to the duration/unit of one day, not the 1st of the month (ついたち).

Common Mistakes

  • Using the month name counter 〜月（がつ） to express duration.

    三月（さんがつ）勉強しました。
    三ヶ月（さんかげつ）勉強しました。

    三月（さんがつ） means 'March'. To say 'for three months', you must use 三ヶ月（さんかげつ）.

  • Mispronouncing April, July, or September when naming months.

    四月（よんがつ）、七月（なながつ）、九月（きゅうがつ）
    四月（しがつ）、七月（しちがつ）、九月（くがつ）

    Months have specific readings for 4, 7, and 9 that do not follow the standard counting rules. For example, April is always 四月（しがつ）.

  • Mispronouncing 'four years' as 四年（よんねん）.

    四年に一度（よんねんにいちど）
    四年に一度（よねんにいちど）

    While 'four' is often 四（よん）, when counting years, it is standardly read as 四年（よねん）. It uses the alternative native reading よ before the counter.

How It Connects

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日/週/月/年Level 1Date/period Counters

Learn This First

To understand date and period counters, learners should first be familiar with basic kanji, the general concept of Japanese counters, and how smaller units of time (hours/minutes) are structured.

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Patterns that build on this one.

Words in This Pattern

週年