How many days is the star character in the movie groundhog day stuck on groundhog day?

42 days/6 weeks

Edit: This answer couldn't be more wrong. Think about it this way....in Phil's time reliving Groundhog Day, he learned intimate details about everybody in the Tip Top Cafe, he learned to ice sculpt, he learned to play the piano, and he learned French, among other things. You couldn't do any single one of those tasks in just 42 days, and certainly not all of them. Plus, the proficiency in which he performs his newly learned skills indicates that he had spent significant time practicing. Just the piano number he plays towards the end of the movie would take YEARS for a beginner to learn. I'd estimate his time reliving February 2nd to be in double-digit years, probably 20 or more, MINIMUM.