Японский календарь эпох: система летоисчисления и история названий эпох ( gengō)

Element that identifies years in the Japanese era calendar

The Japanese era name (年号) 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 (元)"), followed by the literal "nen (年)" meaning "year". Era names originated in 140 BCE in Imperial China, during the reign of the Emperor Wu of Han. As elsewhere in the Sinosphere, 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 name systems. Unlike its other Sinosphere counterparts, Japanese era names are still in official 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 Reiwa (令和) era began on 1 May 2019, the day of accession of Naruhito to the throne as the 126th Emperor of Japan, following the day of the planned and voluntary abdication of his father, the 125th Emperor, Akihito. Emperor Akihito had received special permission to abdicate, rather than serving in his role until his death, as is the rule. The Reiwa (令和) era followed the 31st and final year of the Heisei (Heisei era), which had started on the day after the death of Emperor Hirohito on 8 January 1989.

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.

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) 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). 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.

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 period (Meiji"), and a "one reign, one era name" (一世一元) 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) 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), 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). 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). It is protocol in Japan that the reigning emperor be referred to as Tennō Heika (天皇陛下) or Kinjō Tennō (今上天皇). 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 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). 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.

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), 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.

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 [[:ja:鶴峯戊申#襲国偽僣考 and [[:ja:九州王朝説#九州年号表.

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.

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.

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) 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.

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.

Era namePeriod of useLength of useDerived fromRemarkEmperor KōtokuTaika645–650 AD7 yearsBook of Documents,Book of Han,Book of SongHakuchi650–654 AD5 yearsBook of HanEmperor TenmuShuchō686 AD3 monthsBook of RitesAlso rendered as Suchō, Akamitori, and Akamidori. Emperor MonmuTaihō701–704 AD4 yearsClassic of ChangesAlso rendered as Daihō. Keiun704–708 AD5 yearsSelections of Refined Literature,Book of JinAlso rendered as Kyōun. Usage continued by the Empress Genmei upon her ascension to the throne. Empress GenmeiWadō708–715 AD8 years

Era namePeriod of useLength of useDerived fromRemarkEmpress GenshōReiki715–717 AD3 yearsClassic of ChangesYōrō717–724 AD8 yearsBook of RitesEmperor ShōmuJinki724–729 AD6 yearsBook of Rites with Commentaries of Dai De (大戴禮記),The Literary ExpositorTenpyō729–749 AD21 yearsClassic of Changes,Great LearningAlso rendered as Tenbyō and Tenhei. Tenpyō kanpō749 AD4 monthsAlso rendered as Tenbyō kanpō and Tenhei kanpō. Empress KōkenTenpyō shōhō749–757 AD9 yearsAlso rendered as Tenbyō shōhō and Tenpei shōhō. Tenpyō hōji757–765 AD9 yearsAlso rendered as Tenbyō hōji and Tenpei hōji. Usage continued by the Emperor Junnin and the Empress Shōtoku upon their ascension to the throne. Empress ShōtokuTenpyō jingo765–767 AD3 yearsAlso rendered as Tenbyō jingo and Tenhei jingo. Jingo keiun767–770 AD4 yearsUsage continued by the Emperor Kōnin upon his ascension to the throne. Emperor KōninHōki770–781 AD12 yearsBook of RitesEmperor KanmuTen'ō781–782 AD2 yearsClassic of ChangesEnryaku782–806 AD25 yearsBook of Later HanUsage continued by the Emperor Heizei upon his ascension to the throne.

Era namePeriod of useLength of useDerived fromRemarkEmperor HeizeiDaidō806–810 AD5 yearsBook of RitesUsage continued by the Emperor Saga upon his ascension to the throne. Emperor SagaKōnin810–824 AD15 yearsUsage continued by the Emperor Junna upon his ascension to the throne. Emperor JunnaTenchō824–834 AD11 yearsUsage continued by the Emperor Ninmyō upon his ascension to the throne. Emperor NinmyōJōwa834–848 AD15 yearsAlso rendered as Shōwa and Sōwa. Kashō848–851 AD4 yearsAlso rendered as Kajō. Usage continued by the Emperor Montoku upon his ascension to the throne. Emperor MontokuNinju851–854 AD4 yearsSaikō854–857 AD4 yearsTen'an857–859 AD3 yearsAlso rendered as Tennan. Usage continued by the Emperor Seiwa upon his ascension to the throne. Emperor SeiwaJōgan859–877 AD19 yearsClassic of ChangesUsage continued by the Emperor Yōzei upon his ascension to the throne. Emperor YōzeiGangyō877–885 AD9 yearsAlso rendered as Gankyō and Genkei. Usage continued by the Emperor Kōkō upon his ascension to the throne. Emperor KōkōNinna885–889 AD5 yearsAlso rendered as Ninwa. Usage continued by the Emperor Uda upon his ascension to the throne. Emperor UdaKanpyō889–898 AD10 yearsAlso rendered as Kanpei, Kanbyō, Kanbei, and Kanhei. Usage continued by the Emperor Daigo upon his ascension to the throne. Emperor DaigoShōtai898–901 AD4 yearsEngi901–923 AD23 yearsBook of DocumentsEnchō923–931 AD9 yearsSelections of Refined LiteratureUsage continued by the Emperor Suzaku upon his ascension to the throne. Emperor SuzakuJōhei931–938 AD8 yearsBook of HanAlso rendered as Shōhei. Tengyō938–947 AD10 yearsBook of HanAlso rendered as Tenkei and Tenkyō. Usage continued by the Emperor Murakami upon his ascension to the throne. Emperor MurakamiTenryaku947–957 AD11 yearsAnalectsAlso rendered as Tenreki. Tentoku957–961 AD5 yearsClassic of ChangesŌwa961–964 AD4 yearsBook of JinKōhō964–968 AD5 yearsBook of DocumentsUsage continued by the Emperor Reizei upon his ascension to the throne. Emperor ReizeiAnna968–970 AD3 yearsBook of RitesAlso rendered as Anwa. Usage continued by the Emperor En'yū upon his ascension to the throne. Emperor En'yūTenroku970–974 AD5 yearsTen'en974–976 AD3 yearsJōgen976–978 AD3 yearsAlso rendered as Teigen. Tengen978–983 AD6 yearsEikan983–985 AD3 yearsBook of DocumentsAlso rendered as Yōkan. Usage continued by the Emperor Kazan upon his ascension to the throne. Emperor KazanKanna985–987 AD3 yearsAlso rendered as Kanwa. Usage continued by the Emperor Ichijō upon his ascension to the throne. Emperor IchijōEien987–989 AD3 yearsBook of Han,Book of Later HanAlso rendered as Yōen. Eiso989–990 AD2 yearsBook of Jin,Old Book of TangAlso rendered as Yōso. Shōryaku990–995 AD6 yearsAlso rendered as Jōryaku and Shōreki. Chōtoku995–999 AD5 yearsAdmonishment by the Colonel of the City Gates (城門校尉箴)Also rendered as Jōryaku and Shōreki. Chōhō999–1004 AD6 yearsDiscourses of the StatesKankō1004–1012 AD9 yearsBook of HanUsage continued by the Emperor Sanjō upon his ascension to the throne. Emperor SanjōChōwa1012–1017 AD6 yearsBook of RitesUsage continued by the Emperor Go Ichijō upon his ascension to the throne. Emperor Go IchijōKannin1017–1021 AD5 yearsRecords of Kuaiji (會稽記)Jian1021–1024 AD4 yearsBook of HanAlso rendered as Chian. Manju1024–1028 AD5 yearsClassic of PoetryChōgen1028–1037 AD10 yearsSix Secret TeachingsUsage continued by the Emperor Go Suzaku upon his ascension to the throne. Emperor Go SuzakuChōryaku1037–1040 AD4 yearsSpring and Autumn Annals,Book of JinAlso rendered as Chōreki. Chōkyū1040–1044 AD5 yearsBook of the Way and of VirtueKantoku1044–1046 AD3 yearsBook of Later HanUsage continued by the Emperor Go Reizei upon his ascension to the throne. Emperor Go ReizeiEishō1046–1053 AD8 yearsBook of Documents,Book of Jin,Book of SongAlso rendered as Eijō and Yōjō. Tengi1053–1058 AD6 yearsBook of the Master Who Embraces SimplicityAlso rendered as Tenki. Kōhei1058–1065 AD8 yearsBook of Later HanJiryaku1065–1069 AD5 yearsCorrect 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 SanjōEnkyū1069–1074 AD6 yearsBook of DocumentsUsage continued by the Emperor Shirakawa upon his ascension to the throne. Emperor ShirakawaJōhō1074–1077 AD4 yearsBook of DocumentsAlso rendered as Shōhō and Shōho. Jōryaku1077–1081 AD5 yearsWeicheng Dianxun (維城典訓)Also rendered as Shōryaku and Shōreki. Eihō1081–1084 AD4 yearsBook of DocumentsAlso rendered as Yōhō.Ōtoku1084–1087 AD4 yearsComprehensive Meaning of White Tiger PavilionUsage continued by the Emperor Horikawa upon his ascension to the throne. Emperor HorikawaKanji1087–1094 AD8 yearsBook of RitesKahō1094–1096 AD3 yearsRecords of the Grand HistorianEichō1096–1097 AD2 yearsBook of Later HanAlso rendered as Yōchō. Jōtoku1097–1099 AD3 yearsClassic of ChangesAlso rendered as Shōtoku. Kōwa1099–1104 CE6 yearsTheories of Politics (政論)Chōji1104–1106 CE3 yearsBook of HanKajō1106–1108 CE3 yearsBook of HanUsage continued by the Emperor Toba upon his ascension to the throne. Emperor TobaTennin1108–1110 AD3 yearsSelections of Refined LiteratureTen'ei1110–1113 AD4 yearsBook of DocumentsAlso rendered as Ten'yō. Eikyū1113–1118 AD6 yearsMao CommentaryAlso rendered as Yōkyū. Gen'ei1118–1120 AD3 yearsAlso rendered as Gen'yō. Hōan1120–1124 AD5 yearsUsage continued by the Emperor Sutoku upon his ascension to the throne. Emperor SutokuTenji1124–1126 AD3 yearsClassic of ChangesAlso rendered as Tenchi. Daiji1126–1131 AD6 yearsHetu Tingzuofu (河圖挺佐輔)Also rendered as Taiji. Tenshō1131–1132 AD2 yearsBook of HanAlso rendered as Tenjō. Chōshō1132–1135 AD4 yearsRecords of the Grand HistorianAlso rendered as Chōjō. Hōen1135–1141 AD7 yearsSelections of Refined LiteratureEiji1141–1142 AD2 yearsOn the Standards for Literature (典論),Book of JinUsage continued by the Emperor Konoe upon his ascension to the throne. Emperor KonoeKōji1142–1144 AD3 yearsBook of SongTen'yō1144–1145 AD2 yearsBook of Later HanAlso rendered as Tennyō. Kyūan1145–1151 AD7 yearsBook of JinNinpei1151–1154 AD4 yearsBook of Later HanAlso rendered as Ninpyō, Ninbyō, Ninhyō, and Ninhei. Kyūju1154–1156 AD3 yearsBook of the Master Who Embraces SimplicityUsage continued by the Emperor Go Shirakawa upon his ascension to the throne. Emperor Go ShirakawaHōgen1156–1159 AD4 yearsInstructions 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 NijōHeiji1159–1160 AD2 yearsRecords of the Grand HistorianAlso rendered as Byōji. Eiryaku1160–1161 AD2 yearsBook of Later HanAlso rendered as Yōryaku.Ōhō1161–1163 AD3 yearsBook of DocumentsAlso rendered as Ōpō. Chōkan1163–1165 AD3 yearsWeicheng Dianxun (維城典訓)Also rendered as Chōgan. Eiman1165–1166 AD2 yearsBook of HanAlso rendered as Yōman. Usage continued by the Emperor Rokujō upon his ascension to the throne. Emperor RokujōNin'an1166–1169 AD4 yearsCorrect 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 TakakuraYōwa1181–1182 AD8 yearsBook of Later HanJuei1182–1185 AD4 yearsClassic of PoetryAlso used by the Emperor Go Toba from 1183 AD to 1184 AD. Emperor Go TobaJuei1183–1184 AD2 yearsClassic of PoetryAlso used by the Emperor Antoku from 1182 AD to 1185 AD. Genryaku1184–1185 AD2 yearsShangshu Kaolingyao (尚書考靈耀)

Era namePeriod of useLength of useDerived fromRemarkEmperor Go TobaBunji1185–1190 CE6 yearsBook of RitesAlso rendered as Monchi. Kenkyū1190–1199 CE10 yearsBook of JinUsage continued by the Emperor Tsuchimikado upon his ascension to the throne. Emperor TsuchimikadoShōji1199–1201 CE3 yearsZhuangziAlso rendered as Shōchi. Kennin1201–1204 CE4 yearsSelections of Refined LiteratureGenkyū1204–1206 CE3 yearsCorrect Interpretation of the Mao Commentary (毛詩正義)Ken'ei1206–1207 CE2 yearsSelections of Refined LiteratureAlso rendered as Ken'yō. Jōgen1207–1211 CE5 yearsComprehensive InstitutionsAlso rendered as Shōgen. Usage continued by the Emperor Juntoku upon his ascension to the throne. Emperor JuntokuKenryaku1211–1213 CE3 yearsBook of Later HanAlso rendered as Kenreki. Kempo1213–1219 CE7 yearsBook of DocumentsAlso rendered as Kenhō. Jōkyū1219–1222 CE4 yearsApocrypha 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 HorikawaJōō1222–1224 CE3 yearsClassic of ChangesAlso rendered as Teiō. Gennin1224–1225 CE2 yearsClassic of ChangesKaroku1225–1227 CE3 yearsRecords of Diverse MattersAntei1227–1229 CE3 yearsClassic of ChangesAlso rendered as Anjō. Kangi1229–1232 CE4 yearsBook of WeiAlso rendered as Kanki. Jōei1232–1233 CE2 yearsClassic of ChangesAlso rendered as Teiei. Usage continued by the Emperor Shijō upon his ascension to the throne. Emperor ShijōTenpuku1233–1234 CE2 yearsBook of DocumentsAlso rendered as Tenfuku. Bunryaku1234–1235 CE2 yearsSelections of Refined LiteratureAlso rendered as Monryaku and Monreki. Katei1235–1238 CE4 yearsBook of Northern QiRyakunin1238–1239 CE2 yearsBook of SuiAlso rendered as Rekinin. En'ō1239–1240 CE2 yearsSelections of Refined LiteratureAlso rendered as Ennō. Ninji1240–1243 CE4 yearsNew Book of TangAlso rendered as Ninchi. Usage continued by the Emperor Go Saga upon his ascension to the throne. Emperor Go SagaKangen1243–1247 CE5 yearsBook of SongUsage continued by the Emperor Go Fukakusa upon his ascension to the throne. Emperor Go FukakusaHōji1247–1249 CE3 yearsLuxuriant Dew of the Spring and Autumn AnnalsKenchō1249–1256 CE8 yearsBook of Later HanKōgen1256–1257 CE2 yearsShōka1257–1259 CE3 yearsClassified Collection Based on the Classics and Other LiteratureShōgen1259–1260 CE2 yearsApocrypha of the Classic of Poetry (詩緯)Usage continued by the Emperor Kameyama upon his ascension to the throne. Emperor KameyamaBun'ō1260–1261 CE2 yearsBook of JinAlso rendered as Bunnō. Kōchō1261–1264 CE4 yearsThe Political Program of the Zhenguan Period (貞觀政要)Bun'ei1264–1275 CE12 yearsBook of Later HanUsage continued by the Emperor Go Uda upon his ascension to the throne. Emperor Go UdaKenji1275–1278 CE4 yearsRites of ZhouKōan1278–1288 CE11 yearsVeritable 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 FushimiShōō1288–1293 CE6 yearsNotes on the Mao Commentary (毛詩注)Einin1293–1299 CE7 yearsBook of JinUsage continued by the Emperor Go Fushimi upon his ascension to the throne. Emperor Go FushimiShōan1299–1302 CE4 yearsThe School Sayings of ConfuciusUsage continued by the Emperor Go Nijō upon his ascension to the throne. Emperor Go NijōKengen1302–1303 CE2 yearsClassic of ChangesKagen1303–1306 CE4 yearsClassified Collection Based on the Classics and Other LiteratureTokuji1306–1308 CE3 yearsThe Commentary of ZuoUsage continued by the Emperor Hanazono upon his ascension to the throne. Emperor HanazonoEnkyō1308–1311 CE4 yearsBook of Later HanAlso rendered as Engyō and Enkei.Ōchō1311–1312 CE2 yearsOld Book of TangShōwa1312–1317 CE6 yearsOld Book of TangBunpō1317–1319 CE3 yearsBook of LiangAlso rendered as Bunhō. Usage continued by the Emperor Go Daigo upon his ascension to the throne. Emperor Go DaigoGen'ō1319–1321 CE3 yearsOld Book of TangAlso rendered as Gennō. Genkō1321–1324 CE4 yearsClassic of ChangesShōchū1324–1326 CE3 yearsClassic of ChangesKaryaku1326–1329 CE4 yearsOld Book of TangGentoku1329–1332 CE4 yearsClassic of Changes,Correct Interpretation of the Classic of Changes (周易正義)Genkō1331–1334 CE4 yearsClassified Collection Based on the Classics and Other Literature

Era namePeriod of useLength of useDerived fromRemarkEmperor Go DaigoKenmu1334–1336 CE3 yearsBook of Later HanAlso rendered as Kenbu. Also used by the Emperor Kōmyō from 1336 CE to 1338 CE. Engen1336–1340 CE5 yearsBook of LiangUsage continued by the Emperor Go Murakami upon his ascension to the throne. Emperor Go MurakamiKōkoku1340–1347 CE8 yearsThe Commentary of Zuo,Selections of Refined Literature,New History of the Five DynastiesShōhei1347–1370 CE24 yearsBook of SongUsage continued by the Emperor Chōkei upon his ascension to the throne. Emperor ChōkeiKentoku1370–1372 CE3 yearsSelections of Refined LiteratureBunchū1372–1375 CE4 yearsClassic of ChangesTenju1375–1381 CE7 yearsRecords of the Grand HistorianKōwa1381–1384 CE4 yearsBook of DocumentsUsage continued by the Emperor Go Kameyama upon his ascension to the throne. Emperor Go KameyamaGenchū1384–1392 CE9 yearsClassic of ChangesGenchū 9 was superseded by Meitoku 3 in 1392 CE.

Era namePeriod of useLength of useDerived fromRemarkEmperor KōgonShōkyō1332–1333 CE2 yearsCorrect Interpretation of the Classic of Changes (周易正義)Also rendered as Shōkyō. Emperor KōmyōKenmu1336–1338 CE3 yearsBook of Later HanAlso rendered as Kenbu. Also used by the Emperor Go Daigo from 1334 CE to 1336 CE. Ryakuō1338–1342 CE5 yearsRecords of Emperors and Kings (帝王世紀)Also rendered as Rekiō. Kōei1342–1345 CE4 yearsBook of HanJōwa1345–1350 CE6 yearsClassified Collection Based on the Classics and Other LiteratureAlso rendered as Teiwa. Usage continued by the Emperor Sukō upon his ascension to the throne. Emperor SukōKannō1350–1352 CE3 yearsZhuangziAlso rendered as Kan'ō. Usage continued by the Emperor Go Kōgon upon his ascension to the throne. Emperor Go KōgonBunna1352–1356 CE5 yearsRecords of the Three Kingdoms,Old Book of TangAlso rendered as Bunwa. Enbun1356–1361 CE6 yearsBook of HanKōan1361–1362 CE2 yearsCorrect Interpretation of the Records of the Grand Historian (史記正義),Old Book of TangJōji1362–1368 CE7 yearsClassic of ChangesAlso rendered as Teiji.Ōan1368–1375 CE8 yearsCorrect 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'yūEiwa1375–1379 CE5 yearsBook of Documents,Classified Collection Based on the Classics and Other LiteratureKōryaku1379–1381 CE3 yearsOld Book of TangEitoku1381–1384 CE4 yearsThe Governing Principles of Ancient China (羣書治要)Usage continued by the Emperor Go Komatsu upon his ascension to the throne. Emperor Go KomatsuShitoku1384–1387 CE4 yearsClassic of Filial PietyAlso rendered as MeitokuKakei1387–1389 CE3 yearsCorrect Interpretation of the Mao Commentary (毛詩正義)Also rendered as Kakyō. Kōō1389–1390 CE2 yearsSelections of Refined LiteratureMeitoku1390–1394 CE5 yearsBook of RitesMeitoku 3 superseded Genchū 9 in 1392 CE.

Era namePeriod of useLength of useDerived fromRemarkEmperor Go KomatsuŌei1394–1428 CE35 yearsInstitutional History of TangUsage continued by the Emperor Shōkō upon his ascension to the throne. Emperor ShōkōShōchō1428–1429 CE2 yearsCorrect 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 HanazonoEikyō1429–1441 CE13 yearsBook of Later HanAlso rendered as Eikō. Kakitsu1441–1444 CE4 yearsClassic of ChangesAlso rendered as Kakichi. Bun'an1444–1449 CE6 yearsBook of Documents,Book of JinAlso rendered as Bunnan. Hōtoku1449–1452 CE4 yearsOld Book of TangKyōtoku1452–1455 CE4 yearsBook of DocumentsKōshō1455–1457 CE3 yearsBook of Documents,Records of the Grand HistorianChōroku1457–1460 CE4 yearsHan FeiziKanshō1460–1466 CE7 yearsThe School Sayings of ConfuciusUsage continued by the Emperor Go Tsuchimikado upon his ascension to the throne. Emperor Go TsuchimikadoBunshō1466–1467 CE2 yearsXunziAlso rendered as Monshō.Ōnin1467–1469 CE3 yearsWeicheng Dianxun (維城典訓)Bunmei1469–1487 CE19 yearsClassic of ChangesChōkyō1487–1489 CE3 yearsSelections of Refined Literature,The Commentary of Zuo,Book of Later HanEntoku1489–1492 CE4 yearsMenciusMeiō1492–1501 CE10 yearsClassic of ChangesUsage continued by the Emperor Go Kashiwabara upon his ascension to the throne. Emperor Go KashiwabaraBunki1501–1504 CE4 yearsThe Literary ExpositorEishō1504–1521 CE18 yearsApocrypha of the Classic of Changes (周易緯)Daiei1521–1528 CE8 yearsComprehensive InstitutionsUsage continued by the Emperor Go Nara upon his ascension to the throne. Emperor Go NaraKyōroku1528–1532 CE5 yearsClassic of ChangesTenbun1532–1555 CE24 yearsClassic of ChangesAlso rendered as Tenmon. Kōji1555–1558 CE4 yearsBook of Northern QiUsage continued by the Emperor Ōgimachi upon his ascension to the throne. Emperor ŌgimachiEiroku1558–1570 CE13 yearsThe Governing Principles of Ancient China (羣書治要)Also rendered as Yōroku. Genki1570–1573 CE4 yearsMao Commentary,Selections of Refined Literature

Era namePeriod of useLength of useDerived fromRemarkEmperor ŌgimachiTenshō1573–1592 CE20 yearsSelections of Refined Literature,Book of the Way and of VirtueUsage continued by the Emperor Go Yōzei upon his ascension to the throne. Emperor Go YōzeiBunroku1592–1596 CE5 yearsComprehensive InstitutionsKeichō1596–1615 CE20 yearsCorrect 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.

Era namePeriod of useLength of useDerived fromRemarkEmperor Go MizunooGenna1615–1624 CE10 yearsEra name of the Emperor Xianzong of TangAlso rendered as Genwa. Kan'ei1624–1644 CE21 yearsCollected 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 KōmyōShōhō1645–1648 CE4 yearsBook of DocumentsKeian1648–1652 CE5 yearsClassic of ChangesAlso rendered as Kyōan. Jōō1652–1655 CE4 yearsBook of JinAlso rendered as Shōō. Usage continued by the Emperor Go Sai upon his ascension to the throne. Emperor Go SaiMeireki1655–1658 CE4 yearsBook of Han,Book of Later HanAlso rendered as Myōryaku and Meiryaku. Manji1658–1661 CE4 yearsRecords of the Grand Historian,The Political Program of the Zhenguan Period (貞觀政要)Also rendered as Manchi. Kanbun1661–1673 CE13 yearsXunziUsage continued by the Emperor Reigen upon his ascension to the throne. Emperor ReigenEnpō1673–1681 CE9 yearsBook of SuiAlso rendered as Enhō. Formerly written as "" in kanji. Tenna1681–1684 CE4 yearsBook of Documents,Book of Han,Book of Later Han,ZhuangziAlso rendered as Tenwa. Jōkyō1684–1688 CE5 yearsClassic of ChangesUsage continued by the Emperor Higashiyama upon his ascension to the throne. Emperor HigashiyamaGenroku1688–1704 CE16 yearsSelections of Refined LiteratureHōei1704–1711 CE8 yearsOld Book of TangUsage continued by the Emperor Nakamikado upon his ascension to the throne. Emperor NakamikadoShōtoku1711–1716 CE6 yearsBook of DocumentsKyōhō1716–1736 CE21 yearsBook of ZhouUsage continued by the Emperor Sakuramachi upon his ascension to the throne. Emperor SakuramachiGenbun1736–1741 CE6 yearsSelections of Refined LiteratureKanpō1741–1744 CE4 yearsDiscourses of the StatesAlso rendered as Kanhō. Enkyō1744–1748 CE5 yearsClassified Collection Based on the Classics and Other LiteratureUsage continued by the Emperor Momozono upon his ascension to the throne. Emperor MomozonoKan'en1748–1751 CE4 yearsSelections of Refined LiteratureHōreki1751–1764 CE14 yearsThe 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 SakuramachiMeiwa1764–1772 CE9 yearsBook of DocumentsAlso rendered as Myōwa. Usage continued by the Emperor Go Momozono upon his ascension to the throne. Emperor Go MomozonoAn'ei1772–1781 CE10 yearsSelections of Refined LiteratureUsage continued by the Emperor Kōkaku upon his ascension to the throne. Emperor KōkakuTenmei1781–1789 CE9 yearsBook of DocumentsKansei1789–1801 CE13 yearsThe Commentary of ZuoKyōwa1801–1804 CE4 yearsSelections of Refined LiteratureBunka1804–1818 CE15 yearsClassic of Changes,Book of Later HanUsage continued by the Emperor Ninkō upon his ascension to the throne. Emperor NinkōBunsei1818–1830 CE13 yearsBook of DocumentsTenpō1830–1844 CE15 yearsBook of DocumentsAlso rendered as Tenhō. Kōka1844–1848 CE5 yearsBook of DocumentsUsage continued by the Emperor Kōmei upon his ascension to the throne. Emperor KōmeiKaei1848–1854 CE7 yearsBook of SongAnsei1854–1860 CE7 yearsThe Governing Principles of Ancient China (羣書治要)Man'en1860–1861 CE2 yearsBook of Later HanBunkyū1861–1864 CE4 yearsBook of Later HanGenji1864–1865 CE2 yearsClassic of Changes,Records of the Three KingdomsKeiō1865–1868 CE4 yearsSelections of Refined LiteratureUsage continued by the Emperor Meiji upon his ascension to the throne.

The "one reign, one era name" system was implemented in 1868 AD. Era namePeriod of useLength of useDerived fromRemarkEmperor MeijiMeiji1868–1912 AD45 yearsClassic of ChangesIn 1873 Japan adopted the Seireki (西暦), the Common Era. Nowadays, Japanese people know it as well as the regnal eras. Prior to the introduction of the Gregorian calendar in 1873, the reference calendar was based on the lunisolar Chinese calendar. Emperor TaishōTaishō1912–1926 AD15 yearsClassic of ChangesRejected proposals were Tenkō , Kōka , Eian , Kentoku , Shōtoku Emperor ShōwaShōwa1926–1989 AD64 yearsBook of DocumentsRejected proposals were Jinka , Genka , Jinwa , Dōwa , Keimei , Junmei , Meiho , Kan'an , Gen'an , Ryūsei , Teigyō , Kōbun , Shōmei , Kyōchū AkihitoHeisei1989–2019 AD31 yearsRecords of the Grand Historian,Book of DocumentsRejected proposals were Shūbun , Seika NaruhitoReiwa2019 AD–presentMan'yōshūFirst Japanese era name extracted from Japanese literature instead of Chinese literature. Rejected proposals were Eikō , Kyūka , Kōshi (also rendered as Kōji; ), Banna (also rendered as Banwa; ), Banpo (also rendered as Banhō; ).