what genre is green day

Green Day is an American rock band that formed in the East Bay of California in 1987. They are characterized as punk rock, pop punk, and alternative rock. From the start, the band took notes from the anarchic attitudes and loud, fast, snotty approach of jittery late-70s punk acts like The Jam and Sham 69, but elevated their blasting sound with pop elements like catchy hooks, tightly arranged song structures, and Beatlesque vocal harmonies. Green Day themselves identify as a punk band on numerous occasions in interviews.