"Happy 420" and call for the drug's legalization.

NEW YORK (CBS/AP) 420, 4:20 or 4/20, is a number used by many to denote smoking marijuana and pot smokers from Denver to Durango are gathering today, April 20, to say "Happy 420" and call for the drug's legalization.

The festivities in Denver include a daylong rally in Civic Center Park. The Denver event will include remarks from the director of the National Organization for the Reform of Marijuana Laws.

An unauthorized public smoking event is expected to draw thousands on the campus of the University of Colorado in Boulder. And in Durango, an evening concert is planned to promote a proposal to decriminalize marijuana in small amounts for adults.

But before anyone considers doing anything illegal today, perhaps they should consider this.

In a poll conducted by the Associated Press and CNBC, 55 percent of Americans oppose legalizing marijuana and only 33 percent support it. Those numbers flip flopped for people under 30 with 54 percent in favor of legalizing the drug and 39 percent against.

Support for medical marijuana was widespread, the poll found. Sixty percent were in favor of medical marijuana and 74 percent believe the drug has a medical benefit. Fourteen states already permit medical marijuana. South Dakota will vote on the issue this fall.

The AP-CNBC poll was conducted April 7-12 and involved interviews with 1,001 adults nationwide.