Stereo One writes:
My understanding is the band name orginated somewhere in their Suburban California highschool, when one of their teachers said that it would be a green day in hell if they ever made a success of their lives.

I guess that assertion would make this hell. Not that their album Dookie was the greatest thing ever, it's listenable from start to finish. Try saying that about every rock album you own. If you want those heavy solid distortion guitars, lyrics you can understand, and choruses that sometimes make you want to sing along, go be an idiot and listen to some Green Day.