I've recently been watching movies similar to "Groundhog Day:" "Happy Death Day," "Before I Fall," and "ARQ." Another I know and like is "The Edge of Tomorrow" - like "ARQ," it's science fiction - and they're the two that attempt to explain why the protagonist is caught in a time loop. After watching "Happy Death Day," I wondered how many other movies there were that were like "Groundhog Day." Almost inevitably, there's a Wikipedia entry for that: List of films featuring time loops. But their list includes any kind of time loop, while I was looking specifically at the idea of the same segment of time repeated apparently endlessly. Wikipedia lists "The Girl Who Leapt Through Time" and "Predestination," both of which I've seen - but neither has the structure of "Groundhog Day" so I'm not going to consider them here. Wikipedia's list isn't oriented to finding movies with the same structure of "Groundhog Day," so we're going with my best guesses here.
The Swedish movie "Naken" finds Anders waking up naked in an elevator on his wedding day - over and over. The only review I've found (listed on the Wikipedia page about the movie) is quite negative. For some incredibly bizarre reason, Marlon Wayans decided this bad Swedish movie should be remade in English. His version is currently rated at 0% on Rotten Tomatoes - to the surprise of no one except perhaps the filmmakers. I think I'll pass on both although they definitely fit the criteria.
The exact idea behind "Groundhog Day" when it came out seems to have been a first (repetition of the same day endlessly), although it was only a bit of a twist on the existing idea of reliving some moment in time to get it right - an idea that's been popular in fiction for decades (if not centuries). In film, all three of the "Back to the Future" movies (all of which involve people going back in time to change the way things happened) had been released by 1990, and "Groundhog Day" didn't come along until 1993. The point is - not a particularly new idea.
All of these movies are about "getting the day right." And in every case the main character doesn't initially know what that means - or even that that's the way out.
"Groundhog Day" makes slow but visible changes in Murray's character - but what makes the movie truly succeed is that at the end of the movie the change isn't complete. He's still a bit of an asshole, he's just ... kinder. This is a tricky thing to do, and remains the target that the other movies aim for and can't quite hit. In "Happy Death Day," our heroine (in 16 days, no less) makes a complete transition from "total bitch" to "good person," and it's not very convincing. In "Before I Fall," our heroine eventually figures things out, and forces herself to do the right thing for that one final day. And in "The Edge of Tomorrow" our hero is a coward who first learns to fight to keep himself alive and because he has no choice, and then finds a reason to continue fighting (the survival of humanity wasn't enough) - but ultimately the movie is less about his changing than it is about achievement of the goal. In "ARQ" (the worst of the four), our hero figures out how to stop the loop fairly quickly ... but would like to do it with some people still alive.
I started writing this blog entry without thinking that others might also have attempted to analyze the movie and its derivatives - but it's popularity means that many have ... see the Interpretations and Analysis section of the "Groundhog Day" Wikipedia entry, and also the following "Legacy" section ... I particularly like the religious interpretations, as Buddhism definitely believes in self-improvement through repetition ...
I have no deep insights to add - just that it was fun finding other similar movies and seeing what was done with each of them.
UPDATE 2019-02: "Russian Doll" - hilarious, creepy, thought-provoking, and all-around well done.
UPDATE 2019-06: "Happy Death Day 2U" - a surprisingly good sequel.