During the trailer of the film and early in the film, Sam is about to have a class on Sisyphus. Those familiar with the myth will know this refers to Sisyphus, who was forced by the god to push a massive boulder up a hill endlessly for eternity. Coinciding well with Sam's story, Sam struggles with the task of the futility of being unable to change her fate until she comes to an epiphany, similar to Sisyphus.
The protagonist wakes up every day next to a poster of butterflies. These symbolize the Butterfly Effect, which she at some point describes using birds as an example.
The movie was filmed in 24 days.
The story takes place on Friday February 12th, the same day & date Groundhog Day was originally released.
Based on the book written by Lauren Oliver.