The number reflects urban lore of when kids would meet after school to get high. “We’re gonna meet at 4:20.” It was a code. All of the stuff after comes from that.
you sure about that?? seems the age school gets out at 2PM... dinner time was 5ish... 4:20 seems a little close to dinner and poses a risk of getting busted by the parents being stoned at dinner!! lol...