The twelve names at a glance
The traditional names are wafū getsumei (和風月名), literally Japanese-style month names. Most end in tsuki, month or moon, often voiced to zuki. They belonged to the lunar calendar, whose year began in spring: months one to three were spring, four to six summer, seven to nine autumn, ten to twelve winter. That is why New Year cards still greet the new spring. The wheel shows that old division.
The numbered months, ichigatsu to jūnigatsu, and how dates are read have their own guide. The table gives each old name with its most cited origin.
| Name | Reading | Month | Origin most often cited |
|---|---|---|---|
| 睦月 | mutsuki | 1st | Mutsubi-tsuki, the month of getting along, when relatives gather for New Year |
| 如月 | kisaragi | 2nd | Kinu sara ni kiru, putting on yet another layer of clothes |
| 弥生 | yayoi | 3rd | Iya oi, plants growing ever thicker |
| 卯月 | uzuki | 4th | The month of u no hana, deutzia blossom |
| 皐月 | satsuki | 5th | Sanae-tsuki, the month of planting rice seedlings |
| 水無月 | minazuki | 6th | The month of water, when paddies are flooded |
| 文月 | fumizuki | 7th | Poems written for Tanabata, or rice ears filling |
| 葉月 | hazuki | 8th | Ha ochi zuki, the month leaves fall |
| 長月 | nagatsuki | 9th | Yonaga-zuki, the month of long nights |
| 神無月 | kannazuki | 10th | The month of the gods |
| 霜月 | shimotsuki | 11th | The month of frost |
| 師走 | shiwasu | 12th | Unknown; the kanji suggest teachers or priests running |
Why the names run late: the lunar calendar
Until 1872 Japan used a lunisolar calendar, taiin taiyō reki (太陰太陽暦), literally great-yin great-yang calendar: the moon and the sun. Each month began at the new moon and lasted 29 or 30 days, so twelve months made about 354 days, and a leap month, urūzuki, was added every two or three years to keep up with the seasons. The first month began between late January and about 20 February.
The third day of the twelfth month of Meiji 5 became 1 January 1873, when Japan switched to the Western calendar, and the old names moved onto the new, earlier months. The National Diet Library puts the gap at one to two months. The old calendar also tracked the sun through twenty-four solar terms, which have a guide of their own. The timeline shows 2026, when the lunar year began on 17 February.
| Japanese | Romaji | Meaning |
|---|---|---|
| 今年の旧正月は二月十七日です。 | Kotoshi no kyūshōgatsu wa nigatsu jūshichinichi desu. | This year's lunar New Year is on 17 February. |
| 旧暦と新暦では、一か月ほどずれがあります。 | Kyūreki to shinreki de wa, ikkagetsu hodo zure ga arimasu. | The old and new calendars are about a month apart. |
| 昔の暦は月の満ち欠けで決めていました。 | Mukashi no koyomi wa tsuki no michikake de kimete imashita. | The old calendar was set by the phases of the moon. |
| 今年の十五夜は九月二十五日でした。 | Kotoshi no jūgoya wa kugatsu nijūgonichi deshita. | This year's mid-autumn moon was on 25 September. |
Read them a month late: satsuki, hazuki and nagatsuki
Several names only make sense once shifted. Hazuki, the eighth month, is usually explained as ha ochi zuki, literally leaf-fall month. Falling leaves in August sound wrong, but the eighth lunar month fell roughly in September, when leaves begin to turn. Nagatsuki, from yonaga-zuki, the month of long nights, covered roughly October.
Satsuki, the fifth month, is linked to sanae, rice seedlings. As a lunar month it fell mostly in June, the heart of the rainy season and of rice planting; beside May it loses its logic. A tea or calligraphy teacher might explain the names to a class like this.
| Japanese | Romaji | Meaning |
|---|---|---|
| 皐月は、田植えの月という意味です。 | Satsuki wa, taue no tsuki to iu imi desu. | Satsuki means the month of rice planting. |
| 葉月は、葉が落ちる月だと言われています。 | Hazuki wa, ha ga ochiru tsuki da to iwarete imasu. | Hazuki is said to be the month when leaves fall. |
| 長月は、夜が長くなる月です。 | Nagatsuki wa, yoru ga nagaku naru tsuki desu. | Nagatsuki is the month when the nights grow long. |
| 霜月は、霜が降りる月です。 | Shimotsuki wa, shimo ga oriru tsuki desu. | Shimotsuki is the month when frost forms. |
| 旧暦の八月は、今の九月ごろです。 | Kyūreki no hachigatsu wa, ima no kugatsu goro desu. | The eighth lunar month is around today's September. |
Minazuki and kannazuki: the 無 that probably means of
Two names contain 無, the kanji for nothing. Minazuki, 水無月, looks like the month without water, odd beside rainy June, and kannazuki, 神無月, like the month without gods. The explanation major dictionaries prefer is that the na in both was an old particle equivalent to no, of: the month of water, when paddies are flooded, and the month of the gods. The kanji 無 came later, once people heard na as none.
Reading 無 as none inspired a famous legend: in the tenth month the gods gather at Izumo Taisha in Shimane, leaving the rest of Japan godless. In Izumo it is kamiarizuki (神在月), literally month when the gods are present, and the shrine still times its rites by the lunar calendar: 18 to 25 November in 2026. In Kyoto, minazuki is also a sweet, a triangle of uirō topped with red beans, eaten on 30 June at the half-year purification.
| Japanese | Romaji | Meaning |
|---|---|---|
| 水無月を二つください。 | Minazuki o futatsu kudasai. | Two minazuki, please. |
| 六月三十日に水無月を食べる習慣があります。 | Rokugatsu sanjūnichi ni minazuki o taberu shūkan ga arimasu. | There's a custom of eating minazuki on 30 June. |
| 出雲では、十月を神在月と呼びます。 | Izumo de wa, jūgatsu o kamiarizuki to yobimasu. | In Izumo, the tenth month is called kamiarizuki. |
| 神様が出雲に集まるという言い伝えがあります。 | Kamisama ga Izumo ni atsumaru to iu iitsutae ga arimasu. | There's a legend that the gods gather in Izumo. |
Beyond the basics: origins still argued over
Treat every origin in the table as the leading theory; even the National Diet Library notes that there are several. Kisaragi is a clear case. The kanji 如月 were borrowed from a Chinese name for the second month and are unrelated to the Japanese word, and the layered-clothes story goes back to a twelfth-century poetry manual; rivals include buds swelling. Uzuki may come from u no hana, or the flower from the month. Fumizuki may be about Tanabata poems or ripening rice.
Shiwasu is the hardest. The kanji mean teacher and run, and the story of priests rushing to chant sutras at year's end was recorded in the Heian period, but linguists regard it as folk etymology: the word existed first. A student asking a teacher about it might hear this honest exchange.
| Japanese | Romaji | Meaning |
|---|---|---|
| 十二月を師走と言うのはなぜですか。 | Jūnigatsu o shiwasu to iu no wa naze desu ka. | Why is December called shiwasu? |
| お坊さんも走るほど忙しいから、と言われています。 | Obōsan mo hashiru hodo isogashii kara, to iwarete imasu. | People say it's because even monks are busy enough to run. |
| でも、本当の語源は分かっていないそうです。 | Demo, hontō no gogen wa wakatte inai sō desu. | But apparently the real origin isn't known. |
| 如月の漢字は、中国の呼び名を借りたものです。 | Kisaragi no kanji wa, Chūgoku no yobina o karita mono desu. | The kanji for kisaragi borrow a Chinese name for the month. |
Satsuki-bare and samidare: words that moved with the calendar
The shift left fossils in everyday words. Samidare (五月雨), literally fifth-month rain, is the steady rain of the rainy season, which fell in the fifth lunar month. Satsuki-bare (五月晴れ) originally meant a break of sunshine during those rains. Today most people use it for the clear, fresh weather of modern May, and dictionaries list both meanings. The old sense survives in haiku, where satsuki-bare is still a summer word.
Samidare has a surprising office life. Samidare-shiki, in the style of early-summer rain, means arriving in dribs and drabs, and business emails use it to apologise for sending things piecemeal. You will hear the first line from a neighbour on a bright May morning and read the second in your inbox.
| Japanese | Romaji | Meaning |
|---|---|---|
| 今日は五月晴れですね。 | Kyō wa satsukibare desu ne. | What a beautifully clear day. |
| 五月雨式で申し訳ありません。 | Samidare-shiki de mōshiwake arimasen. | Sorry to send these in bits and pieces. |
| 五月雨が降り続いています。 | Samidare ga furitsuzuite imasu. | The early-summer rain keeps falling. |
Where you meet the old names today
You will rarely hear the old names in conversation, but you will read them. Formal letters open with seasonal phrases such as shiwasu no kō, the season of shiwasu, and every December the news talks about the shiwasu streets. They are also given names: Yayoi, Satsuki and Hazuki are all used for girls, which leads to exchanges like the one below, heard at a first meeting.
| Japanese | Romaji | Meaning |
|---|---|---|
| 師走に入り、何かと慌ただしくなってまいりました。 | Shiwasu ni hairi, nanika to awatadashiku natte mairimashita. | Now that December is here, things have become rather hectic. |
| 師走の街は買い物客でにぎわっています。 | Shiwasu no machi wa kaimonokyaku de nigiwatte imasu. | The December streets are busy with shoppers. |
| 弥生さんって、三月生まれ？ | Yayoi-san tte, sangatsu umare? | Yayoi, were you born in March? |
| はい、三月生まれなので弥生です。 | Hai, sangatsu umare na node Yayoi desu. | Yes, I was born in March, so I'm Yayoi. |
| カレンダーに睦月と書いてあります。 | Karendā ni mutsuki to kaite arimasu. | The calendar says mutsuki. |
- Calendars, in small print beside the month number.
- Letters, haiku and seasonal greetings, for a refined tone.
- Names, including the Yayoi period, named after the Tokyo district where its pottery was first found.
- Sweets and plants, such as minazuki in June and the satsuki azalea, named for when it flowers.
To fix the twelve kanji in memory, run them through Unihongo's free learning games for vocabulary and kanji a few times a week; the shapes of 睦, 皐 and 師 are the ones most learners forget.
Common mistakes with the old month names
Using them for dates in speech. Mutsuki tōka ni aimashō sounds like a period drama. The cause is word lists that present the names as synonyms of ichigatsu and nigatsu. Use numbered months for real dates.
Reading old texts with the modern months. A haiku about satsuki rain is about June, not May. The cause is calendars that print the names beside the modern months. Anything written before 1873 needs the shift of a month or more.
Taking 無 literally. Learners explain minazuki as the month without water and are then puzzled by the rainy season. The 無 most likely stood for of; say the month of water.
Misreading the kanji. 神無月 is kannazuki or kaminazuki, 五月雨 is samidare rather than gogatsu ame, and 師走 is shiwasu, not shisō. These readings belong to the whole word, so learn them as units.