The Emperor's Birthday天皇誕生日[ Tenno tanjyo bi ]
The Emperor's Birthday (天皇誕生日, Tennō Tanjōbi) is a national holiday in the Japanese calendar. It is celebrated on 23 December. The date is determined by the reigning Emperor's birthdate. Emperor Akihito was born on this date in 1933. During the reign of Hirohito (Showa period, 1926–1989), the Emperor's birthday was observed on 29 April. That date remained a public holiday, posthumously renamed Greenery Day in 1989 and Showa Day in 2007.