Greenery Day in Japan Date in the current year: May 4, 2024

The history of Greenery Day begins in 1926, when Emperor Hirohito (Shōwa) ascended the Chrysanthemum Throne. During the Shōwa era, the Emperors' birthday, April 29, was celebrated as a national holiday. Following Hirohito's death in 1989, his son Akihito ascended the throne. Emperor Shōwa's birthday remained a public holiday, but was renamed to Greenery Day.

The holiday's new name was chosen in order to acknowledge Hirohito's love for plants without directly referencing to his era, which was quite controversial from a historical perspective. Officially, Greenery Day is a day to express gratitude for blessings and to commune with nature. However, most Japanese see it as just another non-working day of the Golden Week.

In 2005, public holidays in Japan were revised. Greenery Day was moved to May 4, and April 29 was renamed to Shōwa Day. The changes came into effect in 2007. Before then, May 4 was an unnamed official holiday (citizen's holiday) due to the law, which states that any day between two official holidays is converted into a holiday, too.