The literal opposite to 'green day' it has nothing to do with weed. A 'red night' is when you go out into the streets with a best friend and throw everything out the window and don't care about the after affects. You go nuts and party, smash things up, shag some random person, do a pound of cocaine
, blow up a car, etc. It's a last resort to have fun before you explode. Imagine a rave at a punk-rock club going haywire and everyone there on everything imaginable freaks out. Half the time its not regrettable, though, and music is a big role in it.
Usually you end up dead, in jail, or hurtin pretty bad.