Ancient – medieval The name of is ancient, and derived from the birthday of
Emperor Xuanzong of Tang. It was changed to in 729 in the first year of
Tenpyō, but it was renamed to in the 7th year of Tenpyo (748 in the first year of Katsuho) 19 years later. is taken from
Laozi's . The earliest historical record of an Emperor's birthday celebrations relates to the 6th year of
Hōki in
Emperor Kōnin's reign (775 CE). The Emperor's birthday was already celebrated during the
Heian period. This is recorded in the record of
Hōki 10 (779). It is recorded that: This day being the
Tencho, a great drinking feast was held for all the ministers, fine
sake that are favoured [by the Emperor] were presented. After the feast, stipends were awarded. () An edict dated the 11th day of the Ninth month is also recorded: The 13th day of the Tenth birthday being Our birthday, each year on this day, it is both emotional and celebratory. On this day, all the monks and nuns of the monasteries must on this day turn the sutras and perform the rituals, and no animals should be butchered throughout the country, and all of the officials of inner and outer courts are awarded feasts for the day. The day will be called
Tenchosetsu. Thus the moral merit is used to repay the deceased imperial mother, and the celebration is spread throughout the land. () There is also a description in the as a record of the
Muromachi period.
Modern – contemporary On 26 August 1868 (11 October 1868), a decree by the Daijo-kan said, "22 September, the Emperor's Birthday is equivalent to the Emperor's Birthday." On 22 September (6 November 1868), the Emperor's Birthday was celebrated as a national holiday. In the 2nd year of the Meiji era (1869), the ministers of each country were invited to the Enryokan to receive a drink, and in the 3rd year of the Meiji era (1870), various officials, non-employees, Kazoku, etc. worshiped. The ministers and below received a feast at each ministry, and royal gun salute was shot on various warships. The ritual of the Emperor's Festival was completed in 1872, in the same year of the Emperor's Birthday. Until 1948, it was called .
Tenchōsetsu paralleled , "Chikyū Festival", which referred to the
Empress consort's birthday. That date remained a public holiday, posthumously renamed
Greenery Day in 1989 and
Shōwa Day in 2007. On 30 April 2019, the 125th Emperor
Akihito abdicated as per the
Constitution of Japan and in accordance with the Imperial Code Special Law Concerning the Retirement of the Emperor. Because
Akihito's birthday is 23 December and his successor
Naruhito's is 23 February, 2019 was the first year since the introduction of the Holidays Act in 1948 that there were no Emperor's Birthday celebrations. Because of concerns related to the
COVID-19 pandemic, the public celebrations for
Naruhito's birthday were cancelled in 2020 (
Reiwa 2), 2021 (
Reiwa 3) and 2022 (
Reiwa 4). However, the emperor addressed and thanked the public for their wishes in a press conference and a recorded video message 2020 and 2021 respectively. == Observance ==