The origins of 420 Day are hazy. The number has been linked to rumored police radio codes that supposedly indicate whether there is marijuana on a suspect and it’s also a reference to a popular after school meeting time to smoke, popularized by a group of Californian teens in the 1970s. Either way, 420 Day is becoming a larger holiday as more U.S. states legalize the substance for recreational use. Several St. Louisans told St. Louis on the Air it is high time for Missouri to celebrate legalized recreational cannabis — and that there is still work to be done.