IMO, both are important. It's nice to be able to smoke at 4:20, especially when you wind up doing it two or 3 times in a row during a weekend or something.
But, the date 4/20, for me, is like a super duper holiday. I take the day off from school, and basically just try to smoke as much as I can, with as many people as I can. Especially if I'm just smoking with them for free (I like to do that alot), because then it just adds to the holiday festive peaceful feeling.