Before they were Green Day, Billie Joe Armstrong and Mike Dirnt performed under the name Sweet Children. They changed the name to Green Day in 1989 to avoid confusion with another local band called Sweet Baby. The name 'Green Day' was slang in the California Bay Area for a day spent doing nothing but smoking marijuana. Billie Joe Armstrong wrote a song called 'Green Day' about his first experience with the drug, and the band decided to adopt the title as their name. Although they started in the underground punk scene at 924 Gilman Street, they achieved massive mainstream success with their 1994 album 'Dookie.' Later, their rock opera 'American Idiot' (2004) became a political and cultural milestone, eventually being adapted into a Broadway musical.