The Japanese era name (, neng?, "year name"), also known as geng? (), 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 Sh?wa 55 (i.e. 1980), and H22 stands for Heisei 22 (2010). At 62 years and 2 weeks, Sh?wa is the longest era to date.
The current era is Reiwa (), which began on 1 May 2019, following the 31st (and final) year of the Heisei era (31?). While the Heisei era () 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.
|A graphical timeline is available at|
Timeline of 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 CE, during the reign of Emperor K?toku.
The first era name to be assigned was "Taika" (), celebrating the political and organizational changes which were to flow from the great Taika reform () 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.
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 Onmy?d?. 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 neng? (, 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 neng?'s second year.
Era names indicate the various reasons for their adoption. For instance, the neng? Wad? (), during the Nara period, was declared due to the discovery of copper deposits in Chichibu. Most neng? 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. Tenpy? Kanp? (?), Tenpy? Sh?h? (?), Tenpy? H?ji (?) and Tenpy? Jingo (?) are some famous neng? names that use four characters. Since the Heian period, Confucian thoughts and ideas have been reflected in era names, such as Daid? (), K?nin () and Tench? (). 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.
Mutsuhito assumed the throne in 1867, during the third year of the Kei? () era. On 23 October 1868, the era name was changed to "Meiji" (), and a "one reign, one era name" (?, 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 neng? 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 neng? (, 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 Taish? () era was proclaimed. 1912 is therefore known as both "Meiji 45" and "Taish? 1" (?, Taish? 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 (, geng?-h?). Thus, since 1868, there have only been five era names assigned: Meiji, Taish?, Sh?wa, 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" (?, Meiji Tenn?).
It is protocol in Japan that the reigning emperor be referred to as Tenn? Heika (?, "His Imperial Majesty the Emperor") or Kinj? Tenn? (?, "current emperor"). To call the current emperor by the current era name, i.e. "Reiwa", even in English, 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 era name system that was introduced by Emperor K?toku 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 "" (Bidatsu-Tenn? Gannen, "the first year of Emperor Bidatsu"), and not "?" (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 neng? system to cover all dates from 660 BC through today.
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 shineng? (, "personal era name"), also known as gineng? () or ineng? (). Currently, there are over 40 confirmed shineng?, most of them dating from the middle ages. Shineng? used prior to the reestablishment of the era name system in 701 are usually called itsuneng? ().[a]
Because official records of shineng? are lacking, the range of dates to which they apply is often unclear. For example, the well-known itsuneng? Hakuh? () is normally said to refer to 650-654 CE; a poetic synonym for the Hakuchi era. However, alternate interpretations exist. For example, in the Nich?reki, Hakuh? refers to 661-683 CE, and in some medieval temple documents, Hakuh? refers to 672-685 CE. Thus, shineng? may be used as an alternative way of dating periods for which there is no official era name.
Other well-known itsuneng? and shineng? include H?k? () (591-621+ CE), Suzaku () (686), Fukutoku () (1489-1492), Miroku () (1506-1507 or 1507-1509) and Meiroku () (1540-1543).
The most recent shineng? is Seiro () (1904-1905), named for the Russo-Japanese War.
Edo period scholar Tsurumine Shigenobu proposed that Ky?sh? neng? (?), said to have been used in ancient Kumaso, should also be considered a form of shineng?. This claim is not generally recognized by the academic community. Lists of the proposed Ky?sh? neng? can be seen in the Japanese language entries ? and .
Certain era names have specific characters assigned to them, for instance ? for the Reiwa period, which can also be written as . These are included in Unicode: Code points U+32FF (?), U+337B (?), U+337C (?), U+337D (?) and U+337E (?) are used for the Reiwa, Heisei, Sh?wa, Taish? and Meiji eras, respectively.
Certain calendar libraries support the conversion from and to the era system, as well as rendering of dates using it.
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 "" for Japanese, "NewEra" for other languages. The final name was added in JDK 12.0.1, after it was announced by the Japanese government.
The list of Japanese era names is the result of a periodization system which was established by Emperor K?toku in 645. The system of Japanese era names (, neng?, "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 April 1, 2019, there have been 239 era names.
|Gregorian calendar year||Name of era||Notes|
|(AD)||Kanji||Romanization of Japanese|
|Asuka period (538-710)|
|498||Earliest date for which recorded shi-neng? are identified; "Unofficial neng? system" section below|
|645||Taika||Emperor K?toku, 645-654.|
|654||Era not named; see "Non-Neng? periods" section below|
|686||Shuch?||also Such?, Akamitori or Akamidori; Emperor Tenmu, 672-686.|
|686||Era not named; see "Non-Neng? periods" section below|
|701||Taih?||also Daih?; Emperor Monmu, 697-707.|
|704||Keiun||also Ky?un; Empress Genmei, 707-715.|
|Nara period (710-794)|
|715||Reiki||Empress Gensh?, 715-724.|
|724||Jinki||also Shinki; Emperor Sh?mu, 724-749.|
|729||Tenpy?||also Tenby? or Tenhei|
|749||?||Tenpy?-sh?h?||also Tenby?-sh?b? or Tenpei-sh?h?; Empress K?ken, 749-758.|
|757||?||Tenpy?-h?ji||also Tenby?-h?ji or Tenpei-h?ji; Emperor Junnin, 758-764;Empress Sh?toku, 764-770.|
|765||?||Tenpy?-jingo||also Tenby?-jingo or Tenhei-jingo|
|770||H?ki||Emperor K?nin, 770-781.|
|781||Ten'?||Emperor Kanmu, 781-806.|
|Heian period (794-1185)|
|806||Daid?||Emperor Heizei, 806-809;Emperor Saga, 809-823.|
|810||K?nin||Emperor Junna, 823-833.|
|824||Tench?||Emperor Ninmy?, 833-850.|
|834||J?wa||also Sh?wa or S?wa|
|848||Kash?||also Kaj?; Emperor Montoku, 850-858.|
|857||Ten'an||also Tennan; Emperor Seiwa, 858-876.|
|859||J?gan||Emperor Y?zei, 876-884.|
|877||Gangy?||also Ganky? or Genkei; Emperor K?k?, 884-887.|
|885||Ninna||also Ninwa; Emperor Uda, 887-897.|
|889||Kanpy?||also Kanpei or Kanby? or Kanbei or Kanhei; Emperor Daigo, 887-930.|
|923||Ench?||Emperor Suzaku, 930-946.|
|938||Tengy?||also Tenkei or Tenky?; Emperor Murakami, 946-967.|
|964||K?h?||Emperor Reizei, 967-969.|
|968||Anna||also Anwa; Emperor En'y?, 969-984.|
|983||Eikan||also Y?kan; Emperor Kazan, 984-986.|
|985||Kanna||also Kanwa; Emperor Ichij?, 986-1011.|
|990||Sh?ryaku||also J?ryaku or Sh?reki|
|1004||Kank?||Emperor Sanj?, 1011-1016.|
|1012||Ch?wa||Emperor Go-Ichij?, 1016-1036.|
|1028||Ch?gen||Emperor Go-Suzaku, 1036-1045.|
|1044||Kantoku||Emperor Go-Reizei, 1045-1068.|
|1046||Eish?||also Eij? or Y?j?|
|1069||Enky?||Emperor Go-Sanj?, 1068-1073.|
|1074||J?h?||also Sh?h? or Sh?ho; Emperor Shirakawa, 1073-1086.|
|1077||J?ryaku||also Sh?ryaku or Sh?reki|
|1087||Kanji||Emperor Horikawa, 1087-1107.|
|1106||Kaj?||also Kash? or Kas?; Emperor Toba, 1107-1123.|
|1120||H?an||Emperor Sutoku, 1123-1142.|
|1142||K?ji||Emperor Konoe, 1142-1155.|
|1151||Ninpei||also Ninpy? or Ninby? or Ninhy? or Ninhei|
|1154||Ky?ju||Emperor Go-Shirakawa, 1155-1158.|
|1156||H?gen||also Hogen; Emperor Nij?, 1158-1165.|
|1165||Eiman||also Y?man; Emperor Rokuj?, 1165-1168.|
|1166||Nin'an||also Ninnan; Emperor Takakura, 1168-1180.|
|1177||Jish?||also Jij? or Chish?; Emperor Antoku, 1180-1185.|
|1182||Juei||Emperor Go-Toba, 1183-1198.|
|Kamakura period (1185-1333)|
|1190||Kenky?||Emperor Tsuchimikado, 1198-1210.|
|1207||J?gen||also Sh?gen; Emperor Juntoku, 1210-1221.|
|1219||J?ky?||also Sh?ky?; Emperor Ch?ky?, 1221.Emperor Go-Horikawa, 1221-1232.|
|1232||J?ei||also Teiei; Emperor Shij?, 1232-1242.|
|1234||Bunryaku||also Monryaku or Monreki|
|1240||Ninji||also Ninchi; Emperor Go-Saga, 1242-1246.|
|1243||Kangen||Emperor Go-Fukakusa, 1246-1260.|
|1256||K?gen||Emperor Kameyama, 1260-1274.|
|1264||Bun'ei||Emperor Go-Uda, 1274-1287.|
|1278||K?an||Emperor Fushimi, 1287-1298.|
|1293||Einin||Emperor Go-Fushimi, 1298-1301.|
|1299||Sh?an||Emperor Go-Nij?, 1301-1308.|
|1308||Enky?||also Engy? or Enkei; Emperor Hanazono, 1308-1318.|
|1317||Bunp?||also Bunh?; Emperor Go-Daigo, 1318-1339.|
|Nanboku-ch? period (1334-1392)|
|1384||Gench?||Gench? 9 becomes Meitoku 3 in post Nanboku-ch? reunification|
|1390||Meitoku||Meitoku 3 replaces Gench? 9 in post-Nanboku-ch? reunification|
|Muromachi period (1392-1573)|
|1394||?ei||Emperor Sh?k?, 1412-1428.|
|1428||Sh?ch?||Emperor Go-Hanazono, 1428-1464.|
|1460||Kansh?||Emperor Go-Tsuchimikado, 1464-1500.|
|1492||Mei?||Emperor Go-Kashiwabara, 1500-1526.|
|1521||Daiei||Emperor Go-Nara, 1526-1557.|
|1555||K?ji||Emperor ?gimachi, 1557-1586.|
|Azuchi-Momoyama period (1573-1603)|
|1573||Tensh?||Emperor Go-Y?zei, 1586-1611.|
|1596||Keich?||also Ky?ch?; Emperor Go-Mizunoo, 1611-1629.|
|Edo period (1603-1868)|
|1624||Kan'ei||Empress Meish?, 1629-1643;Emperor Go-K?my?, 1643-1654.|
|1652||J||also Sh; Emperor Go-Sai, 1655-1663.|
|1655||Meireki||also My?ryaku or Meiryaku|
|1661||Kanbun||Emperor Reigen, 1663-1687.|
|1673||Enp?||also Enh?, formerly written|
|1684||J?ky?||Emperor Higashiyama, 1687-1709.|
|1704||H?ei||Emperor Nakamikado, 1709-1735.|
|1716||Ky?h?||Emperor Sakuramachi, 1735-1747.|
|1744||Enky?||Emperor Momozono, 1747-1762.|
|1751||H?reki||also H?ryaku; Empress Go-Sakuramachi, 1762-1771.|
|1764||Meiwa||Emperor Go-Momozono, 1771-1779.|
|1772||An'ei||Emperor K?kaku, 1780-1817.|
|1804||Bunka||Emperor Nink?, 1817-1846.|
|1844||K?ka||Emperor K?mei, 1846-1867.|
|1865||Kei?||Emperor Meiji, 1867-1868.|
|Modern Japan (from 1868)|
|1868||Meiji||Emperor Meiji, 1868-1912.|
|1912||Taish?||Emperor Taish?, 1912-1926.|
|1926||Sh?wa||Emperor Sh?wa, 1926-1989.|
Post-Taika chronology intervals not covered by the neng? system include:
Japanese calendars, both in java.time.chrono and java.util packages support the upcoming Japanese new era, which will be in effect from May 1st, 2019. While the name of the era was yet to be known, placeholder names ("" for Japanese, "NewEra" for other languages) are provided for its display names. The placeholder names will be replaced with the legitimate era name, Reiwa, in a future update, thus applications should not depend on those placeholder names.