Days of the Week and Months in Japanese
Japanese dates follow a logical, highly systematic structure. Unlike English — where "Monday" derives from Old English and "March" comes from the Roman god Mars — Japanese days and months reflect the classical East Asian cosmological system of five elements plus Sun and Moon. Once you understand the system, the entire calendar unlocks.
Days of the Week (曜日)
Every day name ends in 曜日 (ようび, yōbi), meaning "day of the week." The first kanji identifies which celestial body or element the day represents — mirroring the classical seven-planet system of Chinese astronomy.
| Kanji | Hiragana | English | Named After |
|---|---|---|---|
| 月曜日 | げつようび | Monday | 月 (Moon) |
| 火曜日 | かようび | Tuesday | 火 (Fire) |
| 水曜日 | すいようび | Wednesday | 水 (Water) |
| 木曜日 | もくようび | Thursday | 木 (Wood/Jupiter) |
| 金曜日 | きんようび | Friday | 金 (Metal/Gold/Venus) |
| 土曜日 | どようび | Saturday | 土 (Earth/Saturn) |
| 日曜日 | にちようび | Sunday | 日 (Sun) |
Last, Next, Every: Time Modifiers with Days
The key prefixes are: 先 (せん) = last, 今 (こん) = this, 来 (らい) = next, 毎 (まい) = every.
Months (月)
Japanese months are completely regular: simply attach the number to 月 (がつ, gatsu). There are no special month names to memorise.
| Kanji | Hiragana | English |
|---|---|---|
| 一月 | いちがつ | January |
| 二月 | にがつ | February |
| 三月 | さんがつ | March |
| 四月 | しがつ | April |
| 五月 | ごがつ | May |
| 六月 | ろくがつ | June |
| 七月 | しちがつ | July |
| 八月 | はちがつ | August |
| 九月 | くがつ | September |
| 十月 | じゅうがつ | October |
| 十一月 | じゅういちがつ | November |
| 十二月 | じゅうにがつ | December |
Seasons (季節)
Saying Specific Dates
The pattern for a full date is: Year + 年 + Month + 月 + Day + 日. The counter for days uses native Japanese numbers for 1–10 and some irregular readings: 一日 (ついたち, 1st), 二日 (ふつか, 2nd), 三日 (みっか, 3rd), 四日 (よっか, 4th), 五日 (いつか, 5th), 十日 (とおか, 10th), 二十日 (はつか, 20th). From 11th onward: じゅういちにち, じゅうににち, etc.
Special Dates and Holidays
- 元日 (がんじつ) — January 1st, New Year's Day
- お正月 (おしょうがつ) — New Year period (roughly Jan 1–3)
- お盆 (おぼん) — mid-August ancestor festival (usually Aug 13–16)
- クリスマス — Christmas (Dec 25); celebrated more like Valentine's Day in Japan — a romantic holiday
- バレンタインデー — Valentine's Day (Feb 14); women traditionally give chocolates to men
- ホワイトデー — White Day (Mar 14); men give back to women who gave them chocolates
- ゴールデンウィーク — Golden Week (late April – early May); cluster of national holidays
Years: Era System and Western Calendar
Japan uses two year systems simultaneously. The Western year (西暦, せいれき) uses Arabic numerals as in English. The era year system (元号, げんごう) restarts with each new emperor.
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How do you say the days of the week in Japanese?
The days are: 月曜日 (Monday — Moon), 火曜日 (Tuesday — Fire), 水曜日 (Wednesday — Water), 木曜日 (Thursday — Wood), 金曜日 (Friday — Metal/Gold), 土曜日 (Saturday — Earth), 日曜日 (Sunday — Sun). They are all named after the five elements plus Sun and Moon, mirroring the classical East Asian cosmological system.
How do you say the months in Japanese?
Japanese months are simply number + 月 (gatsu): 一月 (January), 二月 (February), 三月 (March), and so on through 十二月 (December). Unlike English, there are no special names — the system is completely regular.
How do you say "next Monday" or "last Friday" in Japanese?
Use 来 (らい, next) or 先 (せん/せ, last/previous) before the day. 来週の月曜日 = next Monday (literally "next week's Monday"). 先週の金曜日 = last Friday. For "every Wednesday" use 毎 (まい): 毎水曜日 or 毎週水曜日.
How do Japanese era years work?
Japan uses a reign-era system alongside the Western calendar. The current era is 令和 (Reiwa), which began in 2019 when Emperor Naruhito ascended. 令和7年 = 2025. The previous era was 平成 (Heisei, 1989–2019) and before that 昭和 (Shōwa, 1926–1989). Official documents often use the era year; Western year (西暦) is also widely used.