Public holidays in Japan (国民の祝日, kokumin no shukujitsu) were first established by the Public Holiday Law (国民の祝日に関する法律, Kokumin no Shukujitsu ni Kansuru Hōritsu, lit.
[7] In addition to the annual holidays listed above, certain events of celebration or mourning related to the imperial family are also treated as national holidays in the year in which they occur.
[13][14] It is intended to coincide with the Bon Festival vacation time, giving Japanese people an opportunity to appreciate Japan's mountains.
Due to Akihito's 2019 birthday being after his abdication but Naruhito's before his accession, this holiday was not celebrated in 2019.
With the Olympics and Paralympics postponed until 2021 due to the COVID-19 pandemic, the government left this change in place for 2020 and passed an amendment to the Olympic and Paralympic Special Measures Act to make a corresponding change to the holidays in 2021, moving them to July 22, July 23, and August 9 respectively.