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 the0