The film was originally called "Forward Thinking" but due to changes in the plot and to give more of a simple 'classic musical' feel, the music director, John Kowalski, suggested the title "One Day."
The film was originally supposed to be much more a science fiction piece, but major changes were made when director Joe Kowalski realized that the plot was far too complicated to explain to anyone.
The whole film is available on YouTube to watch for free.