MONTREAL -- Canadians gathered in cities across the country Saturday to mark April 20, an unofficial annual holiday celebrating cannabis culture.

A large crowd rallied on Parliament Hill in Ottawa to promote the legalization of marijuana despite cold weather.

In Montreal, people gathered at the foot of Mount Royal while hundreds turned out for an event in downtown Toronto.

A rally is also being held in Vancouver.

This year's celebration comes with an extra dose of optimism for pro-legalization activists.

South of the border, Colorado and Washington legalized the drug last November.

Group smoke-outs were planned in American cities from New York to San Francisco.

The origins of the number "420" as a code for pot are hazy, but the date 4/20 has become a day when marijuana users gather together.