Japanese era name

The Japanese era name (Japanese: 年号, Hepburn: nengō, "year name") or gengō (元号), is the first of the two elements that identify years in the Japanese era calendar scheme. The second element is a number which indicates the year number within the era (with the first year being "gan ()"), followed by the literal "nen ()" meaning "year".

Era names originated in 140 BCE in China, during the reign of the Emperor Wu of Han. As elsewhere in East Asia, the use of era names was originally derived from Chinese imperial practice, although the Japanese system is independent of the Chinese, Korean, and Vietnamese era-naming systems. Unlike these other similar systems, Japanese era names are still in use. Government offices usually require era names and years for official papers.

The five era names used since the end of the Edo period in 1868 can be abbreviated by taking the first letter of their romanized names. For example, S55 means Shōwa 55 (i.e. 1980), and H22 stands for Heisei 22 (2010). At 62 years and 2 weeks, Shōwa is the longest era to date.

The current era is Reiwa (令和), which began on 1 May 2019, following the 31st (and final) year of the Heisei era (平成31年). While the Heisei era (平成) started on the day after the death of the Emperor Hirohito (8 January 1989), the Reiwa era began the day after the planned and voluntary abdication of the 125th Emperor Akihito. Emperor Akihito received special one-time permission to abdicate, rather than serving in his role until his death, as is the rule. His elder son, Naruhito, ascended to the throne as the 126th Emperor of Japan on 1 May 2019.

Overview

Keizō Obuchi, Chief Cabinet Secretary, announces the name of the new era "Heisei" (平成), on 7 January 1989.
Yoshihide Suga, Chief Cabinet Secretary, announces the name of the new era "Reiwa" (令和) at the Prime Minister's Official Residence, on 1 April 2019.
1729 Japanese calendar, which used the Jōkyō calendar procedure, published by Ise Grand Shrine
External Timeline A graphical timeline is available at
Japanese era names

The system on which the Japanese era names are based originated in China in 140 BC, and was adopted by Japan in 645 AD, during the reign of Emperor Kōtoku.

The first era name to be assigned was "Taika" (大化), celebrating the political and organizational changes which were to flow from the great Taika reform (大化の改新) of 645. Although the regular practice of proclaiming successive era names was interrupted in the late seventh century, it was permanently re-adopted in 701 during the reign of Emperor Monmu (697–707). Since then, era names have been used continuously up through the present day.

Historical nengō

Prior to the Meiji period, era names were decided by court officials and were subjected to frequent change. A new era name was usually proclaimed within a year or two after the ascension of a new emperor. A new era name was also often designated on the first, fifth and 58th years of the sexagenary cycle, because they were inauspicious years in Onmyōdō. These three years are respectively known as kakurei, kakuun, and kakumei, and collectively known as sankaku. Era names were also changed due to other felicitous events or natural disasters.

In historical practice, the first day of a nengō (元年, gannen) starts whenever the emperor chooses; and the first year continues until the next lunar new year, which is understood to be the start of the nengō's second year.

Era names indicate the various reasons for their adoption. For instance, the nengō Wadō (和銅), during the Nara period, was declared due to the discovery of copper deposits in Chichibu. Most nengō are composed of two kanji, except for a short time during the Nara period when four-kanji names were sometimes adopted to follow the Chinese trend. Tenpyō Kanpō (天平感宝), Tenpyō Shōhō (天平勝宝), Tenpyō Hōji (天平宝字) and Tenpyō Jingo (天平神護) are some famous nengō names that use four characters. Since the Heian period, Confucian thoughts and ideas have been reflected in era names, such as Daidō (大同), Kōnin (弘仁) and Tenchō (天長).[citation needed] Although there currently exist a total of 248 Japanese era names, only 73 kanji have been used in composing them. Out of these 73 kanji, 31 of them have been used only once, while the rest have been used repeatedly in different combinations.

The vast majority of Japanese Era Names were used for less than 10 years, with two being used for less than a year. Only 28 have been used for more than 10 years and less than 30 years. Only Heisei, Oei, Meiji, and Showa have been used for more than 30 years.

Nengō in modern Japan

Mutsuhito assumed the throne in 1867, during the third year of the Keiō (慶応) era. On 23 October 1868, the era name was changed to "Meiji" (明治), and a "one reign, one era name" (一世一元, issei-ichigen) system was adopted, wherein era names would change only upon immediate imperial succession. This system is similar to the now-defunct Chinese system used since the days of the Ming dynasty. The Japanese nengō system differs from Chinese practice, in that in the Chinese system the era name was not updated until the year following the emperor's death.

In modern practice, the first year of a nengō (元年, gannen) starts immediately upon the emperor's accession and ends on 31 December. Subsequent years follow the Gregorian calendar. For example, the Meiji era lasted until 30 July 1912, when the Emperor died and the Taishō (大正) era was proclaimed. 1912 is therefore known as both "Meiji 45" and "Taishō 1" (大正元年, Taishō gannen), although Meiji technically ended on 30 July with Mutsuhito's death.

This practice, implemented successfully since the days of Meiji but never formalized, became law in 1979 with the passage of the Era Name Law (元号法, gengō-hō). Thus, since 1868, there have only been five era names assigned: Meiji, Taishō, Shōwa, Heisei, and Reiwa, each corresponding with the rule of only one emperor. Upon death, the emperor is thereafter referred to by the era of his reign. For example, Mutsuhito is posthumously known as "Emperor Meiji" (明治天皇, Meiji Tennō).

It is protocol in Japan that the reigning emperor be referred to as Tennō Heika (天皇陛下, "His Majesty the Emperor") or Kinjō Tennō (今上天皇, "current emperor"). To call the current emperor by the current era name, i.e. "Reiwa", even in English,[citation needed] is a faux pas, as this is – and will be – his posthumous name. Use of the emperor's given name (i.e., "Naruhito") is rare, and is considered vulgar behaviour in Japanese.

The Emperor Akihito abdicated on 30 April 2019, necessitating a change in nengō. The new name, made public on the morning of 1 May of the same year, is Reiwa (令和).

Periods without era names

The era name system that was introduced by Emperor Kōtoku was abandoned after his death; no era names were designated between 654 and 686. The system was briefly reinstated by Emperor Tenmu in 686, but was again abandoned upon his death about two months later. In 701, Emperor Monmu once again reinstated the era name system, and it has continued uninterrupted through today.

Although use of the Gregorian calendar for historical dates became increasingly common in Japan, the traditional Japanese system demands that dates be written in reference to era names. The apparent problem introduced by the lack of era names was resolved by identifying the years of an imperial reign as a period.

Although in modern Japan posthumous imperial names correspond with the eras of their reign, this is a relatively recent concept, introduced in practice during the Meiji period and instituted by law in 1979. Therefore, the posthumous names of the emperors and empresses who reigned prior to 1868 may not be taken as era names by themselves. For example, the year 572—the year in which Emperor Bidatsu assumed the Chrysanthemum Throne – is properly written as "敏達天皇元年" (Bidatsu-Tennō Gannen, "the first year of Emperor Bidatsu"), and not "敏達元年" (Bidatsu Gannen, "the first year of Bidatsu"), although it may be abbreviated as such. By incorporating both proper era names and posthumous imperial names in this manner, it is possible to extend the nengō system to cover all dates from 660 BCE through today.

Unofficial era name system

In addition to the official era name system, in which the era names are selected by the imperial court, one also observes—primarily in the ancient documents and epigraphs of shrines and temples—unofficial era names called shinengō (私年号, "personal era name"), also known as ginengō (偽年号) or inengō (異年号). Currently, there are over 40 confirmed shinengō, most of them dating from the middle ages. Shinengō used prior to the reestablishment of the era name system in 701 are usually called itsunengō (逸年号).

Because official records of shinengō are lacking, the range of dates to which they apply is often unclear. For example, the well-known itsunengō Hakuhō (白鳳) is normally said to refer to 650–654 CE; a poetic synonym for the Hakuchi era. However, alternate interpretations exist. For example, in the Nichūreki, Hakuhō refers to 661–683 CE, and in some medieval temple documents, Hakuhō refers to 672–685 CE. Thus, shinengō may be used as an alternative way of dating periods for which there is no official era name.

Other well-known itsunengō and shinengō include Hōkō (法興) (591–621+ CE), Suzaku (朱雀) (686), Entoku (延徳) (1460), Miroku (弥勒) (1506–1507 or 1507–1509) and Meiroku (命禄) (1540–1543).

The most recent shinengō is Seiro (征露) (1904–1905), named for the Russo-Japanese War.

Kyūshū nengō

Edo period scholar Tsurumine Shigenobu proposed that Kyūshū nengō (九州年号), said to have been used in ancient Kumaso, should also be considered a form of shinengō. This claim is not generally recognized by the academic community. Lists of the proposed Kyūshū nengō can be seen in the Japanese language entries 鶴峯戊申 and 九州王朝説.

Software support

Character sets

Certain era names have specific characters assigned to them, for instance ㋿ for the Reiwa period, which can also be written as 令和. These are included in Unicode: Code points U+32FF (㋿), U+337B (㍻), U+337C (㍼), U+337D (㍽) and U+337E (㍾) are used for the Reiwa, Heisei, Shōwa, Taishō and Meiji eras, respectively.

Calendar libraries

Certain calendar libraries support the conversion from and to the era system, as well as rendering of dates using it.

Since the release of Java 8, the Japanese calendar is supported in the new Date and time API for the year Meiji 6 (1873) onwards.

Support for the new era in Japanese imperial transition of 2019

Computers and software manufacturers needed to test their systems in preparation for the new era which began on 1 May 2019. Windows provided a test mechanism to simulate a new era ahead of time. Java Development Kit 11 supported this era using the placeholders "元号" for Japanese, "NewEra" for other languages. The final name was added in JDK 12.0.1, after it was announced by the Japanese government.

Unicode code point U+32FF (㋿) was reserved for representing the new era name, Reiwa.

The list of Japanese era names is the result of a periodization system which was established by Emperor Kōtoku in 645. The system of Japanese era names (年号, nengō, "year name") was irregular until the beginning of the 8th century. After 701, sequential era names developed without interruption across a span of centuries. As of 1 April 2019, there have been 239 era names.

List of Japanese era names

To convert a Japanese year to a Gregorian calendar year, find the first year of the Japanese era name (also called nengō). When found, add the number of the Japanese year, then subtract 1.

Asuka period

Era name Period of use Length of use Derived from Remark
Emperor Kōtoku
孝徳天皇
(r. 645–654 AD)
Taika
大化
645–650 AD 7 years Book of Documents,
Book of Han,
Book of Song
Hakuchi
白雉
650–654 AD 5 years Book of Han
Emperor Tenmu
天武天皇
(r. 673–686 AD)
Shuchō
朱鳥
686 AD 3 months Book of Rites Also rendered as Suchō, Akamitori, and Akamidori.
Emperor Monmu
文武天皇
(r. 697–707 CE)
Taihō
大宝
701–704 AD 4 years Classic of Changes Also rendered as Daihō.
Keiun
慶雲
704–708 AD 5 years Selections of Refined Literature,
Book of Jin
Also rendered as Kyōun. Usage continued by the Empress Genmei upon her ascension to the throne.
Empress Genmei
元明天皇
(r. 707–715 CE)
Wadō
和銅
708–715 AD 8 years

Nara period

Era name Period of use Length of use Derived from Remark
Empress Genshō
元正天皇
(r. 715–724 CE)
Reiki
霊亀
715–717 AD 3 years Classic of Changes
Yōrō
養老
717–724 AD 8 years Book of Rites
Emperor Shōmu
聖武天皇
(r. 724–749 AD)
Jinki
神亀
724–729 AD 6 years Book of Rites with Commentaries of Dai De (大戴禮記),
The Literary Expositor
Tenpyō
天平
729–749 AD 21 years Classic of Changes,
Great Learning
Also rendered as Tenbyō and Tenhei.
Tenpyō-kanpō
天平感宝
749 AD 4 months Also rendered as Tenbyō-kanpō and Tenhei-kanpō.
Empress Kōken
孝謙天皇
(r. 749–758 CE; first reign)
Tenpyō-shōhō
天平勝宝
749–757 AD 9 years Also rendered as Tenbyō-shōhō and Tenpei-shōhō.
Tenpyō-hōji
天平宝字
757–765 AD 9 years Also rendered as Tenbyō-hōji and Tenpei-hōji. Usage continued by the Emperor Junnin and the Empress Shōtoku upon their ascension to the throne.
Empress Shōtoku
称徳天皇
(r. 764–770 CE; second reign)
Tenpyō-jingo
天平神護
765–767 AD 3 years Also rendered as Tenbyō-jingo and Tenhei-jingo.
Jingo-keiun
神護景雲
767–770 AD 4 years Usage continued by the Emperor Kōnin upon his ascension to the throne.
Emperor Kōnin
光仁天皇
(r. 770–781 AD)
Hōki
宝亀
770–781 AD 12 years Book of Rites
Emperor Kanmu
桓武天皇
(r. 781–806 AD)
Ten'ō
天応
781–782 AD 2 years Classic of Changes
Enryaku
延暦
782–806 AD 25 years Book of Later Han Usage continued by the Emperor Heizei upon his ascension to the throne.

Heian period

Era name Period of use Length of use Derived from Remark
Emperor Heizei
平城天皇
(r. 806–809 AD)
Daidō
大同
806–810 AD 5 years Book of Rites Usage continued by the Emperor Saga upon his ascension to the throne.
Emperor Saga
嵯峨天皇
(r. 809–823 AD)
Kōnin
弘仁
810–824 AD 15 years Usage continued by the Emperor Junna upon his ascension to the throne.
Emperor Junna
淳和天皇
(r. 823–833 AD)
Tenchō
天長
824–834 AD 11 years Usage continued by the Emperor Ninmyō upon his ascension to the throne.
Emperor Ninmyō
仁明天皇
(r. 833–850 AD)
Jōwa
承和
834–848 AD 15 years Also rendered as Shōwa and Sōwa.
Kashō
嘉祥
848–851 AD 4 years Also rendered as Kajō. Usage continued by the Emperor Montoku upon his ascension to the throne.
Emperor Montoku
文徳天皇
(r. 850–858 AD)
Ninju
仁寿
851–854 AD 4 years
Saikō
斉衡
854–857 AD 4 years
Ten'an
天安
857–859 AD 3 years Also rendered as Tennan. Usage continued by the Emperor Seiwa upon his ascension to the throne.
Emperor Seiwa
清和天皇
(r. 858–876 AD)
Jōgan
貞観
859–877 AD 19 years Classic of Changes Usage continued by the Emperor Yōzei upon his ascension to the throne.
Emperor Yōzei
陽成天皇
(r. 876–884 CE)
Gangyō
元慶
877–885 AD 9 years Also rendered as Gankyō and Genkei. Usage continued by the Emperor Kōkō upon his ascension to the throne.
Emperor Kōkō
光孝天皇
(r. 884–887 AD)
Ninna
仁和
885–889 AD 5 years Also rendered as Ninwa. Usage continued by the Emperor Uda upon his ascension to the throne.
Emperor Uda
宇多天皇
(r. 887–897 AD)
Kanpyō
寛平
889–898 AD 10 years Also rendered as Kanpei, Kanbyō, Kanbei, and Kanhei. Usage continued by the Emperor Daigo upon his ascension to the throne.
Emperor Daigo
醍醐天皇
(r. 897–930 AD)
Shōtai
昌泰
898–901 AD 4 years
Engi
延喜
901–923 AD 23 years Book of Documents
Enchō
延長
923–931 AD 9 years Selections of Refined Literature Usage continued by the Emperor Suzaku upon his ascension to the throne.
Emperor Suzaku
朱雀天皇
(r. 930–946 AD)
Jōhei
承平
931–938 AD 8 years Book of Han Also rendered as Shōhei.
Tengyō
天慶
938–947 AD 10 years Book of Han Also rendered as Tenkei and Tenkyō. Usage continued by the Emperor Murakami upon his ascension to the throne.
Emperor Murakami
村上天皇
(r. 946–967 AD)
Tenryaku
天暦
947–957 AD 11 years Analects Also rendered as Tenreki.
Tentoku
天徳
957–961 AD 5 years Classic of Changes
Ōwa
応和
961–964 AD 4 years Book of Jin
Kōhō
康保
964–968 AD 5 years Book of Documents Usage continued by the Emperor Reizei upon his ascension to the throne.
Emperor Reizei
冷泉天皇
(r. 967–969 CE)
Anna
安和
968–970 AD 3 years Book of Rites Also rendered as Anwa. Usage continued by the Emperor En'yū upon his ascension to the throne.
Emperor En'yū
円融天皇
(r. 969–984 AD)
Tenroku
天禄
970–974 AD 5 years
Ten'en
天延
974–976 AD 3 years
Jōgen
貞元
976–978 AD 3 years Also rendered as Teigen.
Tengen
天元
978–983 AD 6 years
Eikan
永観
983–985 AD 3 years Book of Documents Also rendered as Yōkan. Usage continued by the Emperor Kazan upon his ascension to the throne.
Emperor Kazan
花山天皇
(r. 984–986 AD)
Kanna
寛和
985–987 AD 3 years Also rendered as Kanwa. Usage continued by the Emperor Ichijō upon his ascension to the throne.
Emperor Ichijō
一条天皇
(r. 986–1011 AD)
Eien
永延
987–989 AD 3 years Book of Han,
Book of Later Han
Also rendered as Yōen.
Eiso
永祚
989–990 AD 2 years Book of Jin,
Old Book of Tang
Also rendered as Yōso.
Shōryaku
正暦
990–995 AD 6 years Also rendered as Jōryaku and Shōreki.
Chōtoku
長徳
995–999 AD 5 years Admonishment by the Colonel of the City Gates (城門校尉箴) Also rendered as Jōryaku and Shōreki.
Chōhō
長保
999–1004 AD 6 years Discourses of the States
Kankō
寛弘
1004–1012 AD 9 years Book of Han Usage continued by the Emperor Sanjō upon his ascension to the throne.
Emperor Sanjō
三条天皇
(r. 1011–1016 AD)
Chōwa
長和
1012–1017 AD 6 years Book of Rites Usage continued by the Emperor Go-Ichijō upon his ascension to the throne.
Emperor Go-Ichijō
後一条天皇
(r. 1016–1036 AD)
Kannin
寛仁
1017–1021 AD 5 years Records of Kuaiji (會稽記)
Jian
治安
1021–1024 AD 4 years Book of Han Also rendered as Chian.
Manju
万寿
1024–1028 AD 5 years Classic of Poetry
Chōgen
長元
1028–1037 AD 10 years Six Secret Teachings Usage continued by the Emperor Go-Suzaku upon his ascension to the throne.
Emperor Go-Suzaku
後朱雀天皇
(r. 1036–1045 AD)
Chōryaku
長暦
1037–1040 AD 4 years Spring and Autumn Annals,
Book of Jin
Also rendered as Chōreki.
Chōkyū
長久
1040–1044 AD 5 years Book of the Way and of Virtue
Kantoku
寛徳
1044–1046 AD 3 years Book of Later Han Usage continued by the Emperor Go-Reizei upon his ascension to the throne.
Emperor Go-Reizei
後冷泉天皇
(r. 1045–1068 AD)
Eishō
永承
1046–1053 AD 8 years Book of Documents,
Book of Jin,
Book of Song
Also rendered as Eijō and Yōjō.
Tengi
天喜
1053–1058 AD 6 years Book of the Master Who Embraces Simplicity Also rendered as Tenki.
Kōhei
康平
1058–1065 AD 8 years Book of Later Han
Jiryaku
治暦
1065–1069 AD 5 years Correct Interpretation of the Book of Documents (尚書正義) Also rendered as Chiryaku. Usage continued by the Emperor Go-Sanjō upon his ascension to the throne.
Emperor Go-Sanjō
後三条天皇
(r. 1068–1073 AD)
Enkyū
延久
1069–1074 AD 6 years Book of Documents Usage continued by the Emperor Shirakawa upon his ascension to the throne.
Emperor Shirakawa
白河天皇
(r. 1073–1087 CE)
Jōhō
承保
1074–1077 AD 4 years Book of Documents Also rendered as Shōhō and Shōho.
Jōryaku
承暦
1077–1081 AD 5 years Weicheng Dianxun (維城典訓) Also rendered as Shōryaku and Shōreki.
Eihō
永保
1081–1084 AD 4 years Book of Documents Also rendered as Yōhō.
Ōtoku
応徳
1084–1087 AD 4 years Comprehensive Meaning of White Tiger Pavilion Usage continued by the Emperor Horikawa upon his ascension to the throne.
Emperor Horikawa
堀河天皇
(r. 1087–1107 AD)
Kanji
寛治
1087–1094 AD 8 years Book of Rites
Kahō
嘉保
1094–1096 AD 3 years Records of the Grand Historian
Eichō
永長
1096–1097 AD 2 years Book of Later Han Also rendered as Yōchō.
Jōtoku
承徳
1097–1099 AD 3 years Classic of Changes Also rendered as Shōtoku.
Kōwa
康和
1099–1104 CE 6 years Theories of Politics (政論)
Chōji
長治
1104–1106 CE 3 years Book of Han
Kajō
嘉承
1106–1108 CE 3 years Book of Han Usage continued by the Emperor Toba upon his ascension to the throne.
Emperor Toba
鳥羽天皇
(r. 1107–1123 AD)
Tennin
天仁
1108–1110 AD 3 years Selections of Refined Literature
Ten'ei
天永
1110–1113 AD 4 years Book of Documents Also rendered as Ten'yō.
Eikyū
永久
1113–1118 AD 6 years Mao Commentary Also rendered as Yōkyū.
Gen'ei
元永
1118–1120 AD 3 years Also rendered as Gen'yō.
Hōan
保安
1120–1124 AD 5 years Usage continued by the Emperor Sutoku upon his ascension to the throne.
Emperor Sutoku
崇徳天皇
(r. 1123–1142 AD)
Tenji
天治
1124–1126 AD 3 years Classic of Changes Also rendered as Tenchi.
Daiji
大治
1126–1131 AD 6 years Hetu Tingzuofu (河圖挺佐輔) Also rendered as Taiji.
Tenshō
天承
1131–1132 AD 2 years Book of Han Also rendered as Tenjō.
Chōshō
長承
1132–1135 AD 4 years Records of the Grand Historian Also rendered as Chōjō.
Hōen
保延
1135–1141 AD 7 years Selections of Refined Literature
Eiji
永治
1141–1142 AD 2 years On the Standards for Literature (典論),
Book of Jin
Usage continued by the Emperor Konoe upon his ascension to the throne.
Emperor Konoe
近衛天皇
(r. 1142–1155 AD)
Kōji
康治
1142–1144 AD 3 years Book of Song
Ten'yō
天養
1144–1145 AD 2 years Book of Later Han Also rendered as Tennyō.
Kyūan
久安
1145–1151 AD 7 years Book of Jin
Ninpei
仁平
1151–1154 AD 4 years Book of Later Han Also rendered as Ninpyō, Ninbyō, Ninhyō, and Ninhei.
Kyūju
久寿
1154–1156 AD 3 years Book of the Master Who Embraces Simplicity Usage continued by the Emperor Go-Shirakawa upon his ascension to the throne.
Emperor Go-Shirakawa
後白河天皇
(r. 1155–1158 AD)
Hōgen
保元
1156–1159 AD 4 years Instructions for the Yan Clan (顏氏家訓) Also rendered as Hogen. Usage continued by the Emperor Nijō upon his ascension to the throne.
Emperor Nijō
二条天皇
(r. 1158–1165 CE)
Heiji
平治
1159–1160 AD 2 years Records of the Grand Historian Also rendered as Byōji.
Eiryaku
永暦
1160–1161 AD 2 years Book of Later Han Also rendered as Yōryaku.
Ōhō
応保
1161–1163 AD 3 years Book of Documents Also rendered as Ōpō.
Chōkan
長寛
1163–1165 AD 3 years Weicheng Dianxun (維城典訓) Also rendered as Chōgan.
Eiman
永万
1165–1166 AD 2 years Book of Han Also rendered as Yōman. Usage continued by the Emperor Rokujō upon his ascension to the throne.
Emperor Rokujō
六条天皇
(r. 1165–1168 AD)
Nin'an
仁安
1166–1169 AD 4 years Correct Interpretation of the Mao Commentary (毛詩正義) Also rendered as Ninnan. Usage continued by the Emperor Takakura upon his ascension to the throne.
Emperor Takakura
高倉天皇
(r. 1168–1180 AD)
Kaō
嘉応
1169–1171 AD 3 years Book of Han
Jōan
承安
1171–1175 AD 5 years Book of Documents Also rendered as Shōan.
Angen
安元
1175–1177 AD 3 years Book of Han
Jishō
治承
1177–1181 AD 5 years Hetu Tingzuofu (河圖挺作輔) Also rendered as Jijō and Chishō. Usage continued by the Emperor Antoku upon his ascension to the throne.
Emperor Antoku
安徳天皇
(r. 1180–1185 AD)
Yōwa
養和
1181–1182 AD 8 years Book of Later Han
Juei
寿永
1182–1185 AD 4 years Classic of Poetry Also used by the Emperor Go-Toba from 1183 AD to 1184 AD.
Emperor Go-Toba
後鳥羽天皇
(r. 1183–1198 AD)
Juei
寿永
1183–1184 AD 2 years Classic of Poetry Also used by the Emperor Antoku from 1182 AD to 1185 AD.
Genryaku
元暦
1184–1185 AD 2 years Shangshu Kaolingyao (尚書考靈耀)

Kamakura period

Era name Period of use Length of use Derived from Remark
Emperor Go-Toba
後鳥羽天皇
(r. 1183–1198 CE)
Bunji
文治
1185–1190 CE 6 years Book of Rites Also rendered as Monchi.
Kenkyū
建久
1190–1199 CE 10 years Book of Jin Usage continued by the Emperor Tsuchimikado upon his ascension to the throne.
Emperor Tsuchimikado
土御門天皇
(r. 1198–1210 CE)
Shōji
正治
1199–1201 CE 3 years Zhuangzi Also rendered as Shōchi.
Kennin
建仁
1201–1204 CE 4 years Selections of Refined Literature
Genkyū
元久
1204–1206 CE 3 years Correct Interpretation of the Mao Commentary (毛詩正義)
Ken'ei
建永
1206–1207 CE 2 years Selections of Refined Literature Also rendered as Ken'yō.
Jōgen
承元
1207–1211 CE 5 years Comprehensive Institutions Also rendered as Shōgen. Usage continued by the Emperor Juntoku upon his ascension to the throne.
Emperor Juntoku
順徳天皇
(r. 1210–1221 CE)
Kenryaku
建暦
1211–1213 CE 3 years Book of Later Han Also rendered as Kenreki.
Kempo
建保
1213–1219 CE 7 years Book of Documents Also rendered as Kenhō.
Jōkyū
承久
1219–1222 CE 4 years Apocrypha of the Classic of Poetry (詩緯) Also rendered as Shōkyū. Usage continued by the Emperor Chūkyō and the Emperor Go-Horikawa upon their ascension to the throne.
Emperor Go-Horikawa
後堀河天皇
(r. 1221–1232 CE)
Jōō
貞応
1222–1224 CE 3 years Classic of Changes Also rendered as Teiō.
Gennin
元仁
1224–1225 CE 2 years Classic of Changes
Karoku
嘉禄
1225–1227 CE 3 years Records of Diverse Matters
Antei
安貞
1227–1229 CE 3 years Classic of Changes Also rendered as Anjō.
Kangi
寛喜
1229–1232 CE 4 years Book of Wei Also rendered as Kanki.
Jōei
貞永
1232–1233 CE 2 years Classic of Changes Also rendered as Teiei. Usage continued by the Emperor Shijō upon his ascension to the throne.
Emperor Shijō
四条天皇
(r. 1232–1242 CE)
Tenpuku
天福
1233–1234 CE 2 years Book of Documents Also rendered as Tenfuku.
Bunryaku
文暦
1234–1235 CE 2 years Selections of Refined Literature Also rendered as Monryaku and Monreki.
Katei
嘉禎
1235–1238 CE 4 years Book of Northern Qi
Ryakunin
暦仁
1238–1239 CE 2 years Book of Sui Also rendered as Rekinin.
En'ō
延応
1239–1240 CE 2 years Selections of Refined Literature Also rendered as Ennō.
Ninji
仁治
1240–1243 CE 4 years New Book of Tang Also rendered as Ninchi. Usage continued by the Emperor Go-Saga upon his ascension to the throne.
Emperor Go-Saga
後嵯峨天皇
(r. 1242–1246 CE)
Kangen
寛元
1243–1247 CE 5 years Book of Song Usage continued by the Emperor Go-Fukakusa upon his ascension to the throne.
Emperor Go-Fukakusa
後深草天皇
(r. 1246–1260 CE)
Hōji
宝治
1247–1249 CE 3 years Luxuriant Dew of the Spring and Autumn Annals
Kenchō
建長
1249–1256 CE 8 years Book of Later Han
Kōgen
康元
1256–1257 CE 2 years
Shōka
正嘉
1257–1259 CE 3 years Classified Collection Based on the Classics and Other Literature
Shōgen
正元
1259–1260 CE 2 years Apocrypha of the Classic of Poetry (詩緯) Usage continued by the Emperor Kameyama upon his ascension to the throne.
Emperor Kameyama
亀山天皇
(r. 1260–1274 CE)
Bun'ō
文応
1260–1261 CE 2 years Book of Jin Also rendered as Bunnō.
Kōchō
弘長
1261–1264 CE 4 years The Political Program of the Zhenguan Period (貞觀政要)
Bun'ei
文永
1264–1275 CE 12 years Book of Later Han Usage continued by the Emperor Go-Uda upon his ascension to the throne.
Emperor Go-Uda
後宇多天皇
(r. 1274–1287 CE)
Kenji
建治
1275–1278 CE 4 years Rites of Zhou
Kōan
弘安
1278–1288 CE 11 years Veritable Records of the Emperor Taizong of Tang (唐太宗實錄) Usage continued by the Emperor Fushimi upon his ascension to the throne.
Emperor Fushimi
伏見天皇
(r. 1287–1298 CE)
Shōō
正応
1288–1293 CE 6 years Notes on the Mao Commentary (毛詩注)
Einin
永仁
1293–1299 CE 7 years Book of Jin Usage continued by the Emperor Go-Fushimi upon his ascension to the throne.
Emperor Go-Fushimi
後伏見天皇
(r. 1298–1301 CE)
Shōan
正安
1299–1302 CE 4 years The School Sayings of Confucius Usage continued by the Emperor Go-Nijō upon his ascension to the throne.
Emperor Go-Nijō
後二条天皇
(r. 1301–1308 CE)
Kengen
乾元
1302–1303 CE 2 years Classic of Changes
Kagen
嘉元
1303–1306 CE 4 years Classified Collection Based on the Classics and Other Literature
Tokuji
徳治
1306–1308 CE 3 years The Commentary of Zuo Usage continued by the Emperor Hanazono upon his ascension to the throne.
Emperor Hanazono
花園天皇
(r. 1308–1318 CE)
Enkyō
延慶
1308–1311 CE 4 years Book of Later Han Also rendered as Engyō and Enkei.
Ōchō
応長
1311–1312 CE 2 years Old Book of Tang
Shōwa
正和
1312–1317 CE 6 years Old Book of Tang
Bunpō
文保
1317–1319 CE 3 years Book of Liang Also rendered as Bunhō. Usage continued by the Emperor Go-Daigo upon his ascension to the throne.
Emperor Go-Daigo
後醍醐天皇
(r. 1318–1339 CE)
Gen'ō
元応
1319–1321 CE 3 years Old Book of Tang Also rendered as Gennō.
Genkō
元亨
1321–1324 CE 4 years Classic of Changes
Shōchū
正中
1324–1326 CE 3 years Classic of Changes
Karyaku
嘉暦
1326–1329 CE 4 years Old Book of Tang
Gentoku
元徳
1329–1332 CE 4 years Classic of Changes,
Correct Interpretation of the Classic of Changes (周易正義)
Genkō
元弘
1331–1334 CE 4 years Classified Collection Based on the Classics and Other Literature

Nanboku-chō period

Southern Court

Era name Period of use Length of use Derived from Remark
Emperor Go-Daigo
後醍醐天皇
(r. 1318–1339 CE)
Kenmu
建武
1334–1336 CE 3 years Book of Later Han Also rendered as Kenbu. Also used by the Emperor Kōmyō from 1336 CE to 1338 CE.
Engen
延元
1336–1340 CE 5 years Book of Liang Usage continued by the Emperor Go-Murakami upon his ascension to the throne.
Emperor Go-Murakami
後村上天皇
(r. 1339–1368 CE)
Kōkoku
興国
1340–1347 CE 8 years The Commentary of Zuo,
Selections of Refined Literature,
New History of the Five Dynasties
Shōhei
正平
1347–1370 CE 24 years Book of Song Usage continued by the Emperor Chōkei upon his ascension to the throne.
Emperor Chōkei
長慶天皇
(r. 1368–1383 CE)
Kentoku
建徳
1370–1372 CE 3 years Selections of Refined Literature
Bunchū
文中
1372–1375 CE 4 years Classic of Changes
Tenju
天授
1375–1381 CE 7 years Records of the Grand Historian
Kōwa
弘和
1381–1384 CE 4 years Book of Documents Usage continued by the Emperor Go-Kameyama upon his ascension to the throne.
Emperor Go-Kameyama
後亀山天皇
(r. 1383–1392 CE)
Genchū
元中
1384–1392 CE 9 years Classic of Changes Genchū 9 was superseded by Meitoku 3 in 1392 CE.

Northern Court

Era name Period of use Length of use Derived from Remark
Emperor Kōgon
光厳天皇
(r. 1331–1333 CE)
Shōkyō
正慶
1332–1333 CE 2 years Correct Interpretation of the Classic of Changes (周易正義) Also rendered as Shōkyō.
Emperor Kōmyō
光明天皇
(r. 1336–1348 CE)
Kenmu
建武
1336–1338 CE 3 years Book of Later Han Also rendered as Kenbu. Also used by the Emperor Go-Daigo from 1334 CE to 1336 CE.
Ryakuō
暦応
1338–1342 CE 5 years Records of Emperors and Kings (帝王世紀) Also rendered as Rekiō.
Kōei
康永
1342–1345 CE 4 years Book of Han
Jōwa
貞和
1345–1350 CE 6 years Classified Collection Based on the Classics and Other Literature Also rendered as Teiwa. Usage continued by the Emperor Sukō upon his ascension to the throne.
Emperor Sukō
崇光天皇
(r. 1348–1351 CE)
Kannō
観応
1350–1352 CE 3 years Zhuangzi Also rendered as Kan'ō. Usage continued by the Emperor Go-Kōgon upon his ascension to the throne.
Emperor Go-Kōgon
後光厳天皇
(r. 1352–1371 CE)
Bunna
文和
1352–1356 CE 5 years Records of the Three Kingdoms,
Old Book of Tang
Also rendered as Bunwa.
Enbun
延文
1356–1361 CE 6 years Book of Han
Kōan
康安
1361–1362 CE 2 years Correct Interpretation of the Records of the Grand Historian (史記正義),
Old Book of Tang
Jōji
貞治
1362–1368 CE 7 years Classic of Changes Also rendered as Teiji.
Ōan
応安
1368–1375 CE 8 years Correct Interpretation of the Mao Commentary (毛詩正義) Usage continued by the Emperor Go-En'yū upon his ascension to the throne.
Emperor Go-En'yū
後円融天皇
(r. 1371–1382 CE)
Eiwa
永和
1375–1379 CE 5 years Book of Documents,
Classified Collection Based on the Classics and Other Literature
Kōryaku
康暦
1379–1381 CE 3 years Old Book of Tang
Eitoku
永徳
1381–1384 CE 4 years The Governing Principles of Ancient China (羣書治要) Usage continued by the Emperor Go-Komatsu upon his ascension to the throne.
Emperor Go-Komatsu
後小松天皇
(r. 1382–1412 CE)
Shitoku
至徳
1384–1387 CE 4 years Classic of Filial Piety Also rendered as Meitoku
Kakei
嘉慶
1387–1389 CE 3 years Correct Interpretation of the Mao Commentary (毛詩正義) Also rendered as Kakyō.
Kōō
康応
1389–1390 CE 2 years Selections of Refined Literature
Meitoku
明徳
1390–1394 CE 5 years Book of Rites Meitoku 3 superseded Genchū 9 in 1392 CE.

Muromachi period

Era name Period of use Length of use Derived from Remark
Emperor Go-Komatsu
後小松天皇
(r. 1382–1412 CE)
Ōei
応永
1394–1428 CE 35 years Institutional History of Tang Usage continued by the Emperor Shōkō upon his ascension to the throne.
Emperor Shōkō
称光天皇
(r. 1412–1428 CE)
Shōchō
正長
1428–1429 CE 2 years Correct Interpretation of the Book of Rites (禮記正義) Usage continued by the Emperor Go-Hanazono upon his ascension to the throne.
Emperor Go-Hanazono
後花園天皇
(r. 1428–1464 CE)
Eikyō
永享
1429–1441 CE 13 years Book of Later Han Also rendered as Eikō.
Kakitsu
嘉吉
1441–1444 CE 4 years Classic of Changes Also rendered as Kakichi.
Bun'an
文安
1444–1449 CE 6 years Book of Documents,
Book of Jin
Also rendered as Bunnan.
Hōtoku
宝徳
1449–1452 CE 4 years Old Book of Tang
Kyōtoku
享徳
1452–1455 CE 4 years Book of Documents
Kōshō
康正
1455–1457 CE 3 years Book of Documents,
Records of the Grand Historian
Chōroku
長禄
1457–1460 CE 4 years Han Feizi
Kanshō
寛正
1460–1466 CE 7 years The School Sayings of Confucius Usage continued by the Emperor Go-Tsuchimikado upon his ascension to the throne.
Emperor Go-Tsuchimikado
後土御門天皇
(r. 1464–1500 CE)
Bunshō
文正
1466–1467 CE 2 years Xunzi Also rendered as Monshō.
Ōnin
応仁
1467–1469 CE 3 years Weicheng Dianxun (維城典訓)
Bunmei
文明
1469–1487 CE 19 years Classic of Changes
Chōkyō
長享
1487–1489 CE 3 years Selections of Refined Literature,
The Commentary of Zuo,
Book of Later Han
Entoku
延徳
1489–1492 CE 4 years Mencius
Meiō
明応
1492–1501 CE 4 years Classic of Changes Usage continued by the Emperor Go-Kashiwabara upon his ascension to the throne.
Emperor Go-Kashiwabara
後柏原天皇
(r. 1500–1526 CE)
Bunki
文亀
1501–1504 CE 4 years The Literary Expositor
Eishō
永正
1504–1521 CE 18 years Apocrypha of the Classic of Changes (周易緯)
Daiei
大永
1521–1528 CE 8 years Comprehensive Institutions Usage continued by the Emperor Go-Nara upon his ascension to the throne.
Emperor Go-Nara
後奈良天皇
(r. 1526–1557 CE)
Kyōroku
享禄
1528–1532 CE 5 years Classic of Changes
Tenbun
天文
1532–1555 CE 24 years Classic of Changes Also rendered as Tenmon.
Kōji
弘治
1555–1558 CE 4 years Book of Northern Qi Usage continued by the Emperor Ōgimachi upon his ascension to the throne.
Emperor Ōgimachi
正親町天皇
(r. 1557–1586 CE)
Eiroku
永禄
1558–1570 CE 13 years The Governing Principles of Ancient China (羣書治要) Also rendered as Yōroku.
Genki
元亀
1570–1573 CE 4 years Mao Commentary,
Selections of Refined Literature

Azuchi–Momoyama period

Era name Period of use Length of use Derived from Remark
Emperor Ōgimachi
正親町天皇
(r. 1557–1586 CE)
Tenshō
天正
1573–1592 CE 20 years Selections of Refined Literature,
Book of the Way and of Virtue
Usage continued by the Emperor Go-Yōzei upon his ascension to the throne.
Emperor Go-Yōzei
後陽成天皇
(r. 1586–1611 CE)
Bunroku
文禄
1592–1596 CE 5 years Comprehensive Institutions
Keichō
慶長
1596–1615 CE 20 years Correct Interpretation of the Mao Commentary (毛詩注疏) Also rendered as Kyōchō. Usage continued by the Emperor Go-Mizunoo upon his ascension to the throne.

Edo period

Era name Period of use Length of use Derived from Remark
Emperor Go-Mizunoo
後水尾天皇
(r. 1611–1629 CE)
Genna
元和
1615–1624 CE 10 years Era name of the Emperor Xianzong of Tang Also rendered as Genwa.
Kan'ei
寛永
1624–1644 CE 21 years Collected Commentaries on the Classic of Poetry (詩集傳) Usage continued by the Empress Meishō and the Emperor Go-Kōmyō upon their ascension to the throne.
Emperor Go-Kōmyō
後光明天皇
(r. 1643–1654 AD)
Shōhō
正保
1645–1648 CE 4 years Book of Documents
Keian
慶安
1648–1652 CE 5 years Classic of Changes Also rendered as Kyōan.
Jōō
承応
1652–1655 CE 4 years Book of Jin Also rendered as Shōō. Usage continued by the Emperor Go-Sai upon his ascension to the throne.
Emperor Go-Sai
後西天皇
(r. 1655–1663 AD)
Meireki
明暦
1655–1658 CE 4 years Book of Han,
Book of Later Han
Also rendered as Myōryaku and Meiryaku.
Manji
万治
1658–1661 CE 4 years Records of the Grand Historian,
The Political Program of the Zhenguan Period (貞觀政要)
Also rendered as Manchi.
Kanbun
寛文
1661–1673 CE 13 years Xunzi Usage continued by the Emperor Reigen upon his ascension to the throne.
Emperor Reigen
霊元天皇
(r. 1663–1687 AD)
Enpō
延宝
1673–1681 CE 9 years Book of Sui Also rendered as Enhō. Formerly written as "延寳" in kanji.
Tenna
天和
1681–1684 CE 4 years Book of Documents,
Book of Han,
Book of Later Han,
Zhuangzi
Also rendered as Tenwa.
Jōkyō
貞享
1684–1688 CE 5 years Classic of Changes Usage continued by the Emperor Higashiyama upon his ascension to the throne.
Emperor Higashiyama
東山天皇
(r. 1687–1709 AD)
Genroku
元禄
1688–1704 CE 16 years Selections of Refined Literature
Hōei
宝永
1704–1711 CE 8 years Old Book of Tang Usage continued by the Emperor Nakamikado upon his ascension to the throne.
Emperor Nakamikado
中御門天皇
(r. 1709–1735 AD)
Shōtoku
正徳
1711–1716 CE 6 years Book of Documents
Kyōhō
享保
1716–1736 CE 21 years Book of Zhou Usage continued by the Emperor Sakuramachi upon his ascension to the throne.
Emperor Sakuramachi
桜町天皇
(r. 1735–1747 AD)
Genbun
元文
1736–1741 CE 6 years Selections of Refined Literature
Kanpō
寛保
1741–1744 CE 4 years Discourses of the States Also rendered as Kanhō.
Enkyō
延享
1744–1748 CE 5 years Classified Collection Based on the Classics and Other Literature Usage continued by the Emperor Momozono upon his ascension to the throne.
Emperor Momozono
桃園天皇
(r. 1747–1762 AD)
Kan'en
寛延
1748–1751 CE 4 years Selections of Refined Literature
Hōreki
宝暦
1751–1764 CE 14 years The Political Program of the Zhenguan Period (貞觀政要) Also rendered as Hōryaku. Usage continued by the Empress Go-Sakuramachi upon her ascension to the throne.
Empress Go-Sakuramachi
後桜町天皇
(r. 1762–1771 AD)
Meiwa
明和
1764–1772 CE 9 years Book of Documents Also rendered as Myōwa. Usage continued by the Emperor Go-Momozono upon his ascension to the throne.
Emperor Go-Momozono
後桃園天皇
(r. 1771–1779 AD)
An'ei
安永
1772–1781 CE 10 years Selections of Refined Literature Usage continued by the Emperor Kōkaku upon his ascension to the throne.
Emperor Kōkaku
光格天皇
(r. 1780–1817 AD)
Tenmei
天明
1781–1789 CE 9 years Book of Documents
Kansei
寛政
1789–1801 CE 13 years The Commentary of Zuo
Kyōwa
享和
1801–1804 CE 4 years Selections of Refined Literature
Bunka
文化
1804–1818 CE 15 years Classic of Changes,
Book of Later Han
Usage continued by the Emperor Ninkō upon his ascension to the throne.
Emperor Ninkō
仁孝天皇
(r. 1817–1846 AD)
Bunsei
文政
1818–1830 CE 13 years Book of Documents
Tenpō
天保
1830–1844 CE 15 years Book of Documents Also rendered as Tenhō.
Kōka
弘化
1844–1848 CE 5 years Book of Documents Usage continued by the Emperor Kōmei upon his ascension to the throne.
Emperor Kōmei
孝明天皇
(r. 1846–1867 AD)
Kaei
嘉永
1848–1854 CE 7 years Book of Song
Ansei
安政
1854–1860 CE 7 years The Governing Principles of Ancient China (羣書治要)
Man'en
万延
1860–1861 CE 2 years Book of Later Han
Bunkyū
文久
1861–1864 CE 4 years Book of Later Han
Genji
元治
1864–1865 CE 2 years Classic of Changes,
Records of the Three Kingdoms
Keiō
慶応
1865–1868 CE 4 years Selections of Refined Literature Usage continued by the Emperor Meiji upon his ascension to the throne.

Modern Japan

The "one reign, one era name" (一世一元) system was implemented in 1868 AD.

Era name Period of use Length of use Derived from Remark
Emperor Meiji
明治天皇
(r. 1867–1912 AD)
Meiji
明治
1868–1912 AD 45 years Classic of Changes
Emperor Taishō
大正天皇
(r. 1912–1926 AD)
Taishō
大正
1912–1926 AD 15 years Classic of Changes Rejected proposals were Tenkō (天興), Kōka (興化), Eian (永安), Kentoku (乾徳), Shōtoku (昭徳).
Emperor Shōwa
昭和天皇
(r. 1926–1989 AD)
Shōwa
昭和
1926–1989 AD 64 years Book of Documents Rejected proposals were Jinka (神化), Genka (元化), Jinwa (神和), Dōwa (同和), Keimei (繼明), Junmei (順明), Meiho (明保), Kan'an (寛安), Gen'an (元安), Ryūsei (立成), Teigyō (定業), Kōbun (光文), Shōmei (章明), Kyōchū (協中).
Akihito
明仁
(r. 1989–2019 AD)
Heisei
平成
1989–2019 AD 31 years Records of the Grand Historian,
Book of Documents
Rejected proposals were Shūbun (修文), Seika (正化).
Naruhito
徳仁
(r. 2019 AD–present)
Reiwa
令和
2019 AD–present 4 years, 241 days Man'yōshū First Japanese era name extracted from Japanese literature instead of Chinese literature. Rejected proposals were Eikō (英弘), Kyūka (久化), Kōshi (also rendered as Kōji; 広至), Banna (also rendered as Banwa; 万和), Banpo (also rendered as Banhō; 万保).

Non-nengō periods

Unofficial non-nengō periods (shinengō) before 701 are called itsunengō (逸年号). Pre-Taika chronology intervals include:

  • Reign of Emperor Jimmu, 660–581 BC
  • Reign of Emperor Suizei, 581–548 BC
  • Reign of Emperor Annei, 548–510 BC
  • Reign of Emperor Itoku, 510–475 BC
  • Reign of Emperor Kōshō, 475–392 BC
  • Reign of Emperor Kōan, 392–290 BC
  • Reign of Emperor Kōrei, 290–214 BC
  • Reign of Emperor Kōgen, 214–157 BC
  • Reign of Emperor Kaika, 157–97 BC
  • Reign of Emperor Sujin, 97–29 BC
  • Reign of Emperor Suinin, 29 BC–AD 71
  • Reign of Emperor Keikō, AD 71–131
  • Reign of Emperor Seimu, 131–192
  • Reign of Emperor Chūai, 192–201
  • Regency of Empress Jingū, 201–270
  • Reign of Emperor Ōjin, 270–313
  • Reign of Emperor Nintoku, 313–400
  • Reign of Emperor Richū, 400–406
  • Reign of Emperor Hanzei, 406–412
  • Reign of Emperor Ingyō, 412–454
  • Reign of Emperor Ankō, 454–457
  • Reign of Emperor Yūryaku, 457–480
  • Reign of Emperor Seinei, 480–485
  • Reign of Emperor Kenzō, 485–488
  • Reign of Emperor Ninken, 488–499
  • Reign of Emperor Buretsu, 499–507
  • Reign of Emperor Keitai, 507–534
  • Reign of Emperor Ankan, 534–536
  • Reign of Emperor Senka, 536–540
  • Reign of Emperor Kinmei, 540–572
  • Reign of Emperor Bidatsu, 572–586
  • Reign of Emperor Yōmei, 586–588
  • Reign of Emperor Sushun, 588–593
  • Reign of Emperor Suiko, 593–629
  • Reign of Emperor Jomei, 629–645

Post-Taika chronology intervals not covered by the nengō system include:

See also


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