Do You Remember the 21st Night of September?

I am legitimately blown over to discover that there is an anniversary on September 21st annually that is specifically dedicated to the band Earth, Wind and Fire and the song "September", which famously opens with the line "Do you remember the 21st night of September".

The reason I am so surprised is because I had no idea Earth, Wind and Fire were even famous in Japan. Moreover, I have never heard that song play in Japan before. But yet there is a whole day dedicated to it: Earth, Wind & Fire "September" Day アース・ウインド＆ファイアー「セプテンバー」の日. Reportedly the anniversary was created by Sony Japan. 

The anniversary is officially recognized by the Japan Anniversary Association since 2020, which coincided with the group's 50th anniversary.