Introduction

  • The first Japanese calendar came from China and was brought to Japan by a Buddhist priest from the Korean kingdom of Paekche. In 553, the Yamato court invited the priest to teach astronomy and geography. This calendar was based on the sexagenary cycle (see below): it used twelve branches (支 shi) corresponding to the twelve animal signs and five stems based on five elements (wood, fire, earth, metal, and water) which were used alternately as major stems (positive, older brother, ending in -noe) and minor ones (negative, younger brother, -noto). Each composite sign returned once in sixty years, each cycle starts with "rat-wood-positive" and ended in "boar-water-negative". Even years are positive, odd ones negative in order of the elements. The first cycle started in the year 604 C.E. when the system was adopted. The next cycle will begin in 2044.
  • Farmers, on the other hand, used a different calendar that was based on 24 "points" or seasons (二十四節気 nijūshi sekki) which each lasted for about fifteen days. Those seasons were crucial to calculate the dates for agricultural work.
  • Solar calendars measure the natural year and are more or less equivalent to the period of the earth's revolution around the sun. They measure the natural year in whole numbers of days (365 or 366) and insert leap years to adjust to the natural year. Lunar calendars are based on the phases of the moon and take civil months as the basic unit of measurement. That means that a full moon occurs on the same day of every civil month. In the Chinese and Japanese civil calendar, a new moon occurred on the first day of the month. The lunar calendar year deviated significantly from the natural year, as twelve civil months added up to 353 days. Thus, in some years a 13th month (intercalary month) was added to make sure that a particular month of the civil calendar and particular seasons of the natural year corresponded. Months with 30 days were called dai-no-tsuki (大の月, long months), months with 29 days shō-no-tsuki (小の月, short months) and intercalary months urū-zuki or jungetsu (閏月, leap months).
  • In 1873, Japan introduced the Gregorian calendar, while retaining the traditional calendar based on imperial eras (nengō, see below).

The Old Solar Calendar


While the Japanese civil calendar was a lunar calendar, a solar calendar derived from ancient Chinese astronomers was in use, too, as farmers depended on calculating the best time to plant and to harvest. The natural year was calculated by referring to the period between two instances of the winter solstice. The winter solstice was not the beginning of the solar year but the midpoint of the first of twelve divisions (節 setsu) of the year. Each setsu contained exactly 30.44 days; the beginning was known as sekki (節気), and the midpoint of each setsu as chūki (中期). Winter solstice marked the first chūki of the solar year, so the first setsu occurred fifteen days earlier, around 6 December according to the Gregorian calendar. Each sekki and chūki had its own name and each of the 24 points (二十四節気 nijūshi sekki) corresponded to dates of the Gregorian calendar.

SeasonSekki or chūkiMeaningAssociationGregorian date
SpringRisshun (立春)Beginning of springOld Solar new year4 or 5 February
Usui (雨水)RainwaterSnow turns to rain19 or 20 February
Keichitsu (啓蟄)Insects stop hibernatingInsects emerge in warmer weather5 or 6 March
Shunbun (春分)Vernal equinox21 or 22 March
Seimei (清明)"Pure and clear"Southeasterly winds bring pleasant weather5 or 6 April
Kokū (穀雨)"Grain rains"Grains germinate in spring rains20 or 21 April
SummerRikka (立夏)Beginning of summer5 or 5 May
Shōman (小満)"The lesser ripening"All things growing21 or 22 may
Bōshu (芒種)"Grain beards and seeds"Rice transplanting6 or 7 June
Geshi (夏至)Summer solstice21 or 22 June
Shōsho (小暑)"The lesser heat"Summer heat increases7 or 8 July
Taisho (大暑)"The greater heat"Intense summer heat23 or 24 July
AutumnRisshū (立秋)Beginning of autumn7 or 8 August
Shosho (処暑)"Manageable heat"Autumn winds bring a lessening of heat23 or 24 August
Hakuro (白露)"White dew"Autumn weather, birds migrate8 or 9 September
Shūbun (秋分)Autumnal equinox23 or 24 September
Kanro (寒露)"Cold dew"Colouring leaves, the height of autumn8 or 9 October
Sōkō (霜降)"Frost falls"First frost; the end of autumn23 or 24 October
WinterRittō (立冬)Beginning of winter7 or 8 November
Shōsetsu (小雪)"The lesser snow"Light snowfall22 or 23 November
Taisetsu (大雪)"The greater snow"Heavy snowfall; winter weather7 or 8 December
Tōji (冬至)Winter solstice21 or 22 December
Shōkan (小寒)"The lesser cold"Cold weather increases4 or 5 January
Daikan (大寒)"The greater cold"Intense winter cold20 or 21 January

Zassetsu (雑節)


Zassetsu ("supplementary solar terms)" are days that indicate the change of the seasons.

DateKanjiRomajiComment
3 February節分SetsubunThe eve of Risshun by one definition.
18-24 March春彼岸Haru higanThe seven days surrounding Shunbun.
Vernal Equinox day春社日Haru shanichiIn Shinto. 彼岸中日 (Higan Chunichi) in Buddhism.
2 May八十八夜Hachijū hachiyaLiterally meaning 88 nights (since Risshun).
11 June入梅NyūbaiLiterally meaning entering tsuyu.
2 July半夏生HangeshōOne of the 72 . Farmers take five days off in some regions.
15 July中元ChūgenOfficially 15 July. 15 August in many regions (Tsuki-okure).
20 July夏の土用Natsu no doyōCustom of eating eel on this day.
1 September二百十日Nihyaku tōkaLiterally meaning 210 days (since Risshun).
11 September二百二十日Nihyaku hatsukaLiterally "220 days".
20-26 September秋彼岸Aki higanThe seven days surrounding Shūbun.
Autumal Equinox秋社日Aki shanichiIn Shinto. Called 彼岸中日 in Buddhism.

The Sexagenary Cycle


In addition to cardinal numbers, Chinese and Japanese use two sets for the purpose of counting: one set contains ten terms known as jikkan (十干), the ten stems; the other contains twelve terms called junishi (十二支), the twelve branches. Since ancient times, East Asian peoples have employed these two sets to count years of their civil calendar. When both series are used together they form a greater cycle of sixty combinations, as 60 is the least common multiple of 10 and 12. The jikkan jūnishi (十干十二支), also known as kanshi (干支), is therefore known as the sexagesimal system.

The Ten Stems


NumeralsOn'yomiKunyomi
1甲 (kō)木の兄 (kinoe)
2乙 (otsu)木の弟 (kinoto)
3丙 (hei)火の兄 (hinoe)
4丁 (tei)火の弟 (hinoto)
5戊 (bo)土の兄 (tsuchinoe)
6己 (ki)土の弟 (tsuchinoto)
7庚 (kō)金の兄 (kanoe)
8辛 (shin)金の弟(kanoto)
9壬 (jin)水の兄 (mizunoe)
10癸 (ki)水の弟 (mizunoto)

The Twelve Branches



AnimalOn'yomiKunyomiKanji
ratshi (し)ne (ね)
oxchū (ちゅう)ushi (うし)
tigerin (いん)tora (とら)
hare / rabbitbō (ぼう)u卯 (う)
dragonshin (しん)tatsu (たつ)
snakeshi (し)mi (み)
horsego (ご)uma (うま)
ram / sheepmi (み)/ bi (び)hitsuji (ひつじ)
monkeyshin (しん)saru (さる)
roosteryū (ゆう)tori (とり)
dogjutsu (じゅつ)inu (いぬ)
boargai (がい)i (い)
The system was invented in China before 1100 BCE for the purpose of counting years, months, days and hours as well as for fortune-telling. A person's sixtieth birthday is called kanreki (還暦) and is a particularly auspicious day, as it completes the sexagesimal cycle. In Japan, the sexagenary cycle was adopted in 604 CE. The last cycle started in 1984 and will be completed in 2044. Each of the ten stems corresponds to a certain final digit in the number of a year in the Common Era. 甲 (kō) or 木の兄 (kinoe), the first stem always appears in the sexagenary designation for a year of the Western calendar ending in the digit four.


Traditional Japanese month names


In addition to their Sino-Japanese names, such as shōgatsu (the first civil month) and ichigatsu, nigatsu, sangatsu, etc, the Japanese months had also informal or poetic names which were rarely used as parts of full dates.

MonthKanjiRōmajiMeaning
January睦月Mutsuki"Month of Love"
February如月 or 衣更着Kisaragi / Kinusaragi"Changing Clothes"
March弥生Yayoi"New Life"
April卯月Uzuki
May皐月 or 早月 or 五月Satsuki / Sanaetsuki"Early-rice-planting Month"
June水無月Minatsuki / Minazuki"No water month"
July文月Fuzuki / Fumizuki"Month of Erudition"
August葉月Hazuki"Month of leaves"
September長月Nagatsuki"Long month"
October神無月Kannazuki or Kaminazuki"No god month"; in Izumo also 神有月 (Kamiarizuki, god month)
November霜月Shimotsuki"Frost month"
December師走Shiwasu"Teachers' run", as teachers are busy at the end of the year

Rokuyō



The rokuyō (六曜) is a series of six days based on the Chinese calendar. They supposedly predict whether there will be good or bad fortune during that day. The rokuyō are commonly found on Japanese calendars and are often used to plan weddings and funerals, though most people ignore them in ordinary life. The rokuyō are also known as the rokki (六輝).

KanjiRōmajiMeaning
先勝SenshōGood luck before noon, bad luck afternoon.
友引TomobikiBad things will happen to your friends. Funerals avoided on this day.
先負SenbuBad luck before noon, good luck afternoon.
仏滅ButsumetsuMost unlucky day. Weddings best avoided.
大安TaianThe luckiest day. Good day for weddings.
赤口ShakkōThe hour of the horse (11 am - 1 pm) is lucky. The rest is bad luck.

Hours (刻)



The Japanese hour (刻 koku) traditionally corresponded to two Western hours. One day was therefore divided into twelve hours as follows:

Western hourJapanese hourKanjiBells
23:00-01:00Hour of the RatNe, Nezumi (子)9 bells (九 kokonotsu)
01:00-03:00Hour of the OxUshi (丑)8 bells (八 yatsu)
03:00-05:00Hour of the TigerTora (寅)7 bells (七 nanatsu)
05:00-07:00Hour of the HareU, Usagi (卯)6 bells (六 mutsu)
07:00-09:00Hour of the DragonTatsu (辰)5 bells (五 itsutsu)
09:00-11:00Hour of the SnakeMi (巳)4 bells (四 yotsu)
11:00-13:00Hour of the HorseUma (午)9 bells (九 kokonotsu)
13:00-15:00Hour of the SheepHitsuji (未)8 bells (八 yatsu)
15:00-17:00Hour of the MonkeySaru (申)7 bells (七 nanatsu)
17:00-19:00Hour of the RoosterTori (酉)6 bells (六 mutsu)
19:00-21:00Hour of the DogInu (戌)5 bells (五 itsutsu)
21:00-23:00Hour of the BoarInoshishi (亥)4 bells (四 yotsu)
The duration of a koku varied slightly depending on the season. During winter solstice it was 1 hour 48 minutes during the day and 2 hours 12 minutes during the night, at the summer solstice, one koku was 2 hours 36 minutes during the day and 1 hour 21 minutes during the night.


See our resources on

Nengō (年号)


Nengō, Japanese era names, are an imitation of Chinese practice adopted in Japan in 645 CE. The first Japanese era name that commemorated groundbreaking political reforms was Taika ("Great Reform"). Except for a brief interruption in the seventh century, nengō have been in continual use ever since. A new era was declared within a year or two after a new emperor had acceded the throne. In addition, at two points in each sexagenary cycle, the first year and the 58th (both considered highly auspicious), a new era was proclaimed. Often, era names were changed in the case of joyous or inauspicious events.

The era name might indicate the reason for its adoption, but for the most part, the characters have a favourable connotation and allude to the classics of Chinese Confucianism. Only the latest era name, Reiwa (令和), is breaking with tradition, as it is based on the Man’yoshu (万葉集), a Japanese classic. All era names are read according to the Sino-Japanese on readings (音読み on'yomi). Premodern nengō were not "reign names"; only after 1868, era names were applied to the whole reign of an emperor. Starting from Meiji Period, nengō have been designated as posthumous names of the emperors whose reigns they commemorate.

To find the Western equivalent for a Japanese era year, one has to take the Western year in which the first year of the nengō began, subtract one and add the number of the era year. To convert Heisei 29, one has to take the first year, 1989, subtract one and add 29; the corresponding Western year is 2017.

Shinengō are unofficial or private era designations that have never been adopted by the Japanese court. Pre-Taika era names are known as itsunengō (逸年号). During the Nanboku-chō period (1336 to 1392), when two imperial courts, the Northern court in Kyōto and the Southern court in Yoshino, vied for legitimacy, both designated their own nengō. Historically, the Southern Court is widely regarded as the legitimate one.

Year (Gregorian calendar)Era name in kanjiRomanized era name
645大化Taika
650白雉Hakuchi (also known as Hakuhō period (白鳳時代)
654No era name-
672白鳳Hakuhō
686朱鳥Shuchō (also known as Suchō, Akamitori or Akamidori)
686No era name-
701大宝Daihō / Taihō
704慶雲Keiun / Kyōun
708和銅Wadō
715霊亀Reiki
717養老Yōrō
724神亀Jinki / Shinki
729天平Tempyō (also Tenbyō or Tenhei)
749天平感宝Tempyō-kampō / Tenbyō-kanpō
749天平勝宝Tempyō-shōhō (also Tenbyō-shōbō or Tenpei-shōhō)
757天平宝字Tempyō-hōji (also Tenbyō-hōji or Tenpei-hōji)
765天平神護Tempyō-jingo (also Tenbyō-jingo or Tenhei-jingo)
767神護景雲Jingo-keiun
770宝亀Hōki
781天応Ten'ō
782延暦Enryaku
806大同Daidō
810弘仁Kōnin
824天長Tenchō
834承和Jōwa / Shōwa
848嘉祥Kajō
851仁寿Ninju
854斉衡Saikō
857天安Tennan / Te'nan
859貞観Jōgan
877元慶Genkei (also Gangyō or Gankyō)
885仁和Ninna / Ninwa
889寛平Kanpyō (also Kanpei, Kanbyō, Kanbei or Kanhei
898昌泰Shōtai
901延喜Engi
923延長Enchō
931承平Jōhei / Shōhei
938天慶Tengyō (also Tenkei or Tenkyō)
947天暦Tenryaku / Tenreki
957天徳Tentoku
961応和Ōwa
964康保Kōhō
968安和Anna / Anwa
970天禄Tenroku
973天延Ten'en
976貞元Jōgen / Teigen
978天元Tengen
983永観Eikan / Yōkan
985寛和Kanna / Kanwa
987永延Eien / Yōen
988永祚Eiso / Yōso
990正暦Shōryaku (also Jōryaku or Shōreki)
995長徳Chōtoku
999長保Chōhō
1004寛弘Kankō
1012長和Chōwa
1017寛仁Kannin
1021治安Jian / Chian
1024万寿Manju
1028長元Chōgen
1037長暦Chōryaku / Chōreki
1040長久Chōkyū
1044寛徳Kantoku
1046永承Eishō (also Eijō or Yōjō)
1053天喜Tengi / Tenki
1058康平Kōhei
1065治暦Jiryaku / Chiryaku
1069延久Enkyū
1074承保Jōhō (also Shōhō or Shōho)
1077承暦Shōryaku (also Jōryaku or Shōreki)
1081永保Eihō / Yōhō
1084応徳Ōtoku
1087寛治Kanji
1094嘉保Kahō
1096永長Eichō / Yōchō
1097承徳Jōtoku / Shōtoku
1099康和Kōwa
1104長治Chōji
1106嘉承Kajō (also Kashō or Kasō)
1108天仁Tennin
1110天永Ten'ei / Ten'yō
1113永久Eikyū / Yōkyū
1118元永Gen'ei
1120保安Hōan
1124天治Tenji / Tenchi
1126大治Daiji / Taiji
1131天承Tenshō / Tenjō
1132長承Chōshō / Chōjō
1135保延Hōen
1141永治Eiji
1142康治Kōji
1144天養Ten'yō / Tennyō
1145久安Kyūan
1151仁平Nimpei (also Ninpyō, Ninbyō, Ninhyō or Ninhei)
1154久寿Kyūju
1156保元Hōgen / Hogen
1159平治Heiji / Byōji
1160永暦Eiryaku / Yōryaku
1161応保Ōhō
1163長寛Chōkan / Chōgan
1165永万Eiman / Yōman
1166仁安Ninnan / Nin'an
1169嘉応Kaō
1171承安Shōan / Jōan
1175安元Angen
1177治承Jishō (also Jijō or Chishō)
1181養和Yōwa
1182寿永Juei
1184元暦Genryaku
1185文治Bunji / Monchi
1190建久Kenkyū
1199正治Shōji
1201建仁Kennin
1204元久Genkyū
1206建永Ken'ei / Ken'yō
1207承元Jōgen / Shōgen
1211建暦Kenryaku
1213建保Kempō / Kenhō
1219承久Jōkyū / Shōkyū
1222貞応Jōō / Teiō
1224元仁Gennin
1225嘉禄Karoku
1227安貞Antei / Anjō
1229寛喜Kanki / Kangi
1232貞永Jōei / Teiei
1233天福Tenpuku / Tenfuku
1234文暦Bunryaku (also Monryaku or Monreki)
1235嘉禎Katei
1238暦仁Ryakunin / Rekinin
1239延応En'ō / Ennō
1240仁治Ninji / Ninchi
1243寛元Kangen
1247宝治Hōji
1249建長Kenchō
1256康元Kōgen
1257正嘉Shōka
1259正元Shōgen
1260文応Bun'ō / Bunnō
1261弘長Kōcho
1264文永Bun'ei
1275建治Kenji
1278弘安Kōan
1288正応Shōō
1293永仁Einin
1299正安Shōan
1302乾元Kengen
1303嘉元Kagen
1306徳治Tokuji
1308延慶Enkyō (also Engyō or Enkei)
1311応長Ōchō
1312正和Shōwa
1317文保Bunpō / Bunhō
1319元応Gen'ō / Gennō
1321元亨Genkyō / Genkō
1324正中Shōchū
1326嘉暦Karyaku
1329元徳Gentoku
1331元弘Genkō
Nanboku-chō periodSouthern Court
1334建武Kemmu / Kenbu
1336延元Engen
1340興国Kōkoku
1346正平Shōhei
1370建徳Kentoku
1372文中Bunchū
1375天授Tenju
1381弘和Kōwa
1384元中Genchū
Nanboku-chō periodNorthern Court
1332正慶Shōkei / Shōkyō
1334建武Kenmu / Kenbu
1338暦応Ryakuō / Rekiō
1342康永Kōei
1345貞和Jōwa / Teiwa
1350観応Kannō / Kan'ō
1352文和Bunna / Bunwa
1356延文Enbun
1361康安Kōan
1362貞治Jōji / Teiji
1368応安Ōan
1375永和Eiwa
1379康暦Kōryaku
1381永徳Eitoku
1384至徳Shitoku
1387嘉慶Kakei / Kakyō
1389康応Kōō
1390明徳Meitoku (Meitoku 3 replaced Genchū 9 post-Nanboku-chō
1394応永Ōei
1428正長Shōchō
1429永享Eikyō / Eikō
1441嘉吉Kakitsu / Kakichi
1444文安Bunnan / Bun'an
1449宝徳Hōtoku
1452享徳Kyōtoku
1455康正Kōshō
1457長禄Chōroku
1460寛正Kanshō
1466文正Bunshō / Monshō
1467応仁Ōnin
1469文明Bunmei
1487長享Chōkyō
1489延徳Entoku
1492明応Meiō
1501文亀Bunki
1504永正Eishō
1521大永Daiei
1528享禄Kyōroku
1532天文Tembun / Temmon
1555弘治Kōji
1558永禄Eiroku
1570元亀Genki
1573天正Tenshō (suggested by Oda Nobunaga)
1592文禄Bunroku
1596慶長Keichō / Kyōchō
1615元和Genna / Genwa
1624寛永Kan'ei
1644正保Shōhō
1648慶安Keian / Kyōan
1652承応Jōō / Shōō
1655明暦Meireki (also Myōryaku or Meiryaku)
1658万治Manji
1661寛文Kambun
1673延宝 (延寳)Empō / Enhō
1681天和Tenna / Tenwa
1684貞享Jōkyō
1688元禄Genroku
1704宝永Hōei
1711正徳Shōtoku
1716享保Kyōhō
1736元文Gembun
1741寛保Kampō / Kanhō
1744延享Enkyō
1748寛延Kan'en
1751宝暦Hōreki / Hōryaku
1764明和Meiwa
1772安永An'ei
1781天明Tenmei
1789寛政Kansei
1801享和Kyōwa
1804文化Bunka
1818文政Bunsei
1830天保Tempō / Tenhō
1844弘化Kōka
1848嘉永Kaei
1854安政Ansei
1860万延Man'en
1861文久Bunkyū
1864元治Genji
1865慶応Keiō
1868明治Meiji
1912大正Taishō
1926昭和Shōwa
1989平成Heisei
2019令和Reiwa
[TR]

References:

  • Like
Reactions: Lomaster