The movie took only nine months to write, film, and edit. Researching (on time travel) took approximately three months.
There have been three different titles for this movie: "Almanac", "Project Almanac", and "Welcome to Yesterday".
In the scene where the characters are watching an airline crash on their laptop, the footage is of a real-life B-52 crash that killed four Air Force officers in 1994. Relatives of the officers complained about the crash appearing in the film, and producer Michael Bay apologized. The scene was supposedly removed, but it was still there when the movie aired on British TV in April 2018.
Each cast member learned their lines in five days.
The plane crash video that they watch on the laptop is the same footage used in the movie Flight (2012) with Denzel Washington, but with further video editing.