It's code for marijuana. Pothead friendly...LOL

stands for weed.. its the number because april 20th, 420, use to be national weed day..least here in ny anyway..

hummm and I dont even partake...

All answeres right on so far, just depends on how far back in time you wanna go..

It refers to an additional charge beyond solicitation that could land you in jail instead of just a fine and slap on the wrist. Its the first and biggest flag to run, don't walk away.

The explanation I got was from my time managing a ski and snowboard shop; as you may know, some of the clientele of these establishments have been know to indulge in the weed from time to time.

As it was explained to me by my younger employees, as the lifts generally stop running at 4:00 PM, the last run of the day down the mountain would be celebrated at the end by lighting up. As it generally took 20 minutes to make a run, you'd be enjoying your end-of-the-day toke at 4:20.

As Wavy Gravy said in the article, it's probably lost in the mists of time...or smoke