The Japanese Imperial calendar year system

The Japanese Imperial calendar year system

In 1872, the Meiji government declared that February 11, 660 BC was the exact date on which the reign of Jimmu began. Emperor Jimmu (神武天皇, Jinmu-tennō) was the 1st emperor of Japan, according to the traditional order of succession. Jimmu is known as the founder of the Imperial dynasty.
This date was therefore identified as the start of the Japanese nation.

A national holiday was establishd to commemorate the anniversary of Jimmu’s ascension to the throne 2,532 years earlier.

This mythical date was designated as the holiday Kigensetsu ("Era Day"). This national holiday was celebrated from 1872 to 1948.

The Kigensetsu events in 1940 were special. They celebrated what was believed to be 2,600 years since the start of Emperor.

There are no certain dates for this emperor’s life or reign. The names and sequence of the early emperors were not confirmed as "traditional" until the reign of Emperor Kammu, who was the 50th monarch of the Yamato dynasty.

Historians debate whether or not Emperor Jimmu actually existed because there is limited evidence of him. Some stories about him may reflect actual events that happened.

The Japanese Imperial calendar year system

The Kigen (紀元) or KoKi (皇紀) is based on the date of the legendary founding of Japan by Emperor Jimmu in 660 BC. It was first used in the official calendar in 1873. However, it never replaced Era names, and since World War II has been completely abandoned. It is seldom found on ceramics and I have seen only one, thanks to Sandra Andacht.

Here is a fine example (ID#2275) of dating using this Imperial year system.

Source Wikipedia