How did Green Day get their name?

In 1986, friends Billie Joe Armstrong and Mike Dirnt, 14 years old at the time, formed a band called Sweet Children. In 1988, Armstrong and Dirnt began working with former Isocracy drummer John Kiffmeyer.

In 1988, Larry Livermore, owner of Lookout! Records, saw the band play an early show and signed the group to his label. In 1989, the band recorded its debut extended play, 1,000 Hours. Before 1,000 Hours was released, the group dropped the name Sweet Children; according to Livermore, this was done to avoid confusion with another local band Sweet Baby. The band adopted the name Green Day, due to the members' fondness for cannabis.