The movie, as everyone knows, is about a man who finds himself living the same day over and over and over again. He is the only person in his world who knows this is happening, and after going through periods of dismay and bitterness, revolt and despair, suicidal self-destruction and cynical recklessness, he begins to do something that is alien to his nature. He begins to learn.

This man is named Phil, and he is a weatherman. In a sense, he feels himself condemned to repeating the same day, anyway; the weather changes, but his on-camera shtick remains the same, and he is distant and ironic about his job. Every year on Feb. 2 he is dispatched to Punxsutawney, Pa., to cover the festivities of Groundhog Day, on which Punxsutawney Phil, the groundhog, is awakened from his slumbers and studied to discover if he will see his shadow. If he does, we will have another six weeks of winter. We usually have another six weeks of winter, anyway, a fact along with many others that does not escape Phil as he signals his cynicism about this transcendentally silly event.

Phil is played by Bill Murray, and Murray is indispensable; before he makes the film wonderful, he does a more difficult thing, which is to make it bearable. I can imagine a long list of actors, whose names I will charitably suppress, who could appear in this material and render it simpering, or inane. The screenplay by Danny Rubin and Harold Ramis is inspired, but inspired crucially because they saw Bill Murray in it. They understood how he would be able to transform it into something sublime, while another actor might reduce it to a cloying parable. Ramis and Murray had worked together from the dawn of their careers, at Second City in Chicago, and knew each other in the ways only improvisational actors can know each other, finding their limits and strengths in nightly risks before a volatile and boozy audience. I doubt if Ramis would have had the slightest interest in directing this material with anyone else but Murray. It wasn't the story that appealed to him, but the thought of Murray in it.

The Murray persona has become familiar without becoming tiring: The world is too much with him, he is a little smarter than everyone else, he has a detached melancholy, he is deeply suspicious of joy, he sees sincerity as a weapon that can be used against him, and yet he conceals emotional needs. He is Hamlet in a sitcom world. "Lost in Translation," another film that works because Bill Murray is in it, captures these qualities. So does "The Life Aquatic with Steve Zissou," which doesn't work because Murray's character has nothing to push against in a world that is as detached as he is.