What is Japanese era name

Japan counts years using a system of era names. The current era is Heisei, which began when Emperor Akihito(the current Emperor of Japan) succeeded his father in 1989. A new era will begin when his heir takes the throne.

The Japanese era name (年号 nengō, "year name"), also known as gengō (元号), is the first of the two elements that identify years in the Japanese era calendar scheme. The second element, a number, indicates the year number within the era (with the first year being "Gan (元)"). The third (and final) part is the literal "nen (年)" meaning "year."

In East Asia, countries that were vassals of China traditionally used Chinese era names to number their years, and if a country used its own year-numbering system, that indicated its non-vassal status.  There were also cases where countries followed the Chinese system for external purposes but used their own calendars domestically.

In pre-modern Japan, a new era name was sometimes adopted to mark the accession of a new emperor, but it was also common to change the gengō on other occasions, such as in the wake of a natural disaster. A single era could include parts of the reigns of two emperors, such as the Keiō era, which started in 1865 under Emperor Kōmei and ended in 1868, during the reign of Emperor Meiji.