Greenery Day was established in 1989 to celebrate the birthday of Japanese Emperor Hirohito. April 29 was set aside to connect with nature and show thanks for all of it’s beauty and gifts, as Hirohito (the Shōwa Emperor) loved plants.
A law was passed in 2005 pertaining to public holidays, and Greenery Day was officially moved to May 4 in 2007. April 29 is now celebrated as Shōwa Day, and commemorates the 63 year reign of the controversial wartime emperor, Hirohito (1926-1989). On this day, the Japanese people are encouraged to reflect on the tumultuous rule of the Shōwa Emperor and think about the future of their country.