Reiwa is the current era of Japan’s official calendar. It began on 1 May 2019, the day Emperor Akihito’s elder son, Naruhito, ascended the throne as the 126th Emperor of Japan. It therefore marks the first Japanese era name with characters that were taken from Japanese literature instead of classic Chinese literature.
The Japanese government , however ,announced the name during a live televised press conference, on 1 April 2019 as Chief Cabinet Secretary Yoshihide Suga traditionally revealed the kanji calligraphy on a board. The Prime Minister Shinzo Abe said that Reiwa represents “a culture being born and nurtured by people coming together beautifully”.
Source: https://www.discoverwalks.com/blog/tokyo/10-most-famous-historical-events-that-happened-in-japan/