Nengō

Nengō are era names assigned to periods of time in Japan. Each name marks a new era, traditionally beginning with an emperor’s accession or a significant event.

Japanese calendar: The calendar system used in Japan, combining Gregorian dates with traditional era-year notation. Nengō provide the era-year component used alongside Gregorian dates.
Chinese era name: A reign-era designation used by Chinese rulers to organize and symbolize periods of time. Japan adapted the era-name practice from Chinese political and calendrical traditions.
Emperor of Japan: The hereditary monarch who serves as Japan’s head of state and symbol of the nation. Modern era changes occur with the accession of a new emperor.
Japanese imperial year: A year count based on the legendary founding of Japan by Emperor Jimmu in 660 BCE. Unlike nengō, this system counts continuously rather than restarting with each era.
Reiwa: The Japanese era that began on 1 May 2019, following Emperor Akihito’s abdication. It is the current era name and a direct example of the modern system.
Taika era: The first recognized Japanese nengō, adopted in 645 during the Taika Reform period. Its adoption marks the beginning of Japan’s own era-name system.
Akihito: The emperor of Japan from 1989 until his abdication in 2019, now known as Emperor Emeritus. His abdication created Japan’s first modern era transition without a death.
Gregorian calendar: The solar calendar introduced by Pope Gregory XIII in 1582 and now used internationally. It numbers years continuously, while nengō restart their count at each era change.
Heisei: The Japanese era that lasted from 8 January 1989 to 30 April 2019. Its transition to Reiwa shows how an imperial succession changes era names.
Taika Reform: A set of political and administrative reforms initiated in Japan in the seventh century. The reforms provide the historical setting for the first Japanese era name.

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