I’m not talking about the holidays with multiple movies anyone can instantly list (so not Christmas, Thanksgiving, Halloween and such) but movies that take place on a more obscure one, where being on that holiday is a plot point. The perfect example being Groundhog’s Day. What else is there? Any Arbor Day movies? Take Your Daughter to Work Day? Ash Wednesday? You get the idea.
(Just thought of two: The Fugitive has a Saint Patrick’s Day parade scene and Ferris Buller’s Day Off was what googling showed to be Von Steuben Day.)
Jam (2006) was one of those movies where a bunch of different characters and stories were joined by a common theme; in this case the common theme was how people were spending Father’s Day. (In an ironic bit of trivia, the company that produced the movie was named Thanksgiving Films.)
Dirty Dancing has Labor Day weekend as the climax, does that count? It’s not really a plot point, but the unofficial end of summer is a big deal at a holiday resort, no?