Columbia Pictures released Groundhog Day in 1993 at a time before production companies whittled their branding to the narrow focuses they have today. Columbia was pretty broad in its interests back in 1993, which you can see from a quick scan of the movies it released immediately before and after Groundhog Day.
In 1992, they released the Oscar-winning courtroom drama A Few Good Men ("You Can't Handle the Truth!") and in 1993 they released Last Action Hero, a weird comedy-action flick that many people would argue is the worst film ever made. Go figure…but hey: Columbia was willing to take some risks.
The production history of Groundhog Day can completely change the way we look at this movie, especially when you focus on the question of how many days Phil Connors is supposed to actually spend stuck in February 2nd. When screenwriter Danny Rubin first handed the script to director Harold Ramis, Rubin wanted the movie to start right in the middle of Phil's struggles and to give us no background at all on how Phil found himself in his predicament. But Ramis and the folks at Columbia felt like audiences would get mad if they couldn't see Phil's slow realization of what was happening to him.
So here's the deal with the whole "number of days" question. Harold Ramis says in the movie's DVD commentary that Phil Connors is probably stuck in Groundhog Day for ten years, and that's the explanation many people tend to go with. But in a later interview, Ramis said that ten years was too short and that it was probably more like 30 or 40 years.