India, April 21 -- It's April 20 (4/20), and millions of Americans, like every year, are celebrating the Marijuana holiday. The National Day Calendar notes that 420 day was 'once an unconventional day' but has 'become the rallying cry of those who seek to legalize marijuana for medicinal and recreational uses'. But why April 20?

While there is no concrete reason for how 420 came into being, several theories have surfaced over the years. One of them traces 420 to Marin County, California, where, in 1971, five students at San Rafael High School would meet at 4:20 PM to partake. They chose the specific time because school activities had usually ended by then. The five students were identified as Steve Capper, Dave Reddix, Jeffrey Noel, Larr...