In most of the country, yesterday was Valentine's Day, but for New York Gov. Hugh Carey, the New York State Department of Commerce and friends it was "I Love New York" Day.

The day of light snowfall, lots of hearts and lots of media hype began at 7:30 a.m. when Darlene Javitz, Miss New York State, distributed buttons reading "I (a symbol of a heart) NY" to commuters at Grand Central Station.

That, someone who didn't "heart NY" might have remarked, was just an hour before a chimpanzee named Judy entered New York Hospital for removal of a facial tumor after being flown from Liberia, where Judy is a vital part of a medical research project on hepatitis.

But someone who did love New York would have noted that the governor and a crowd of Broadway and political celebrities made it through the snow to Central Park's Tavern on the Green restaurant to eat shrimps, avocados and veal piccata in honor of a television commercial soon to be shown in Washington and other markets in the Northeast promoting the city and Broadway theater.

Lunch was Act One, For Act Two, the crowd reassembled at New York's hottest discotheque, Studio 54, for a party hosted by three of New York's media stars - Margaux Hemingway, Gilda Radner and Carrie Fisher.

"We have to spend a little money to make money," New York's Commerce Commissioner John Dyson told the luncheon. He said every dollar New York is spending is bringing three dollars into the state, whose beleaguered treasury badly needs the $4.6 billion that tourism here generates annually.

Carey, Mayor Edward Koch and stars of "Dracula," "The Wiz" and "The King and I" clustered around a Valentine cake to cut it for the photographers.

"You just put a knife through the heart of New York," someone remarked to Koch as he carved, "I was afraid to that," the mayor replied.

Carey said: "I never nicked it," as the hearts were cut apart for the luncheon crowd.

When Giovanni da Verrazano sailed into the harbor, Koch said, his first words were: "I Love New York." Later in New York's history, the mayor added, Peter Minuit bought Manhattan Island from the Indians and his first words were: "We can't pay a dollar more unless we get help from Washington." Then, Koch said, Minuit added: "I Love New York."

Koch, whose young mayoralty has been plagued by snow-removal problems after two blizzards, said he had arranged yesterday's snowstorm to give sparkle to the park scenery outside the restaurant. "If you go a couple of blocks from here," there's no snow, the mayor said, keeping a grinning upper lip.

Bella Abzug, whose political life was at stake yesterday in her effort to return to Congress after losing campaigns for the Senate and for City Hall, stopped by the luncheon.

"You haven't voted, she kidded supporters who were sitting warmly in the Tavern on the Green. "A free lunch is more important than electing a good member of Congress" She ate and left to visit polling places hoping to pull a victory out of the ligt turnout in the 18th District special election.

The centerpiece for the day, appropriately enough for a media event, was the television commercial in which Broadway stars sing the specially commissioned "I Love New York" song written by Steve Karmen. The commercial has an ending the luncheon crowd judged boffo. Frank Langella, who plays Dracula in the hit show, appears in a puff of smoke to say with Draculean menace: "I Love New York, especially in the evenings."

Andy Warhol, Lee Radziwill, Yul Brynner and Barbara Walters were among those who turned out for the luncheon. "The heart of New York," Gov. Carey told them, "is big enough so you can feel its thump through all the United States."

The thump, New York hopes, will be big enough to fill more theater seats, more restaurant tables and more hotels with other Americans who don't think of New York as their Valentine.