A Japanese national holiday celebrated on April 29th. Called midori no hi (緑の日) in Japanese, Greenery Day is similar to Earth Day, with the same basic spirit.
Greenery Day commemorates the birthday of the Showa emperor Hirohito, (yes that Hirohito), who was a great lover of plants and nature. It was first held in 1989, the year of his death.
Greenery Day is the first day of Golden Week.