Question: is the movie about time based on a book

Answer: No, By Curtis's own admission the conception of the idea ``was a slow growth''. The genesis of the idea came when Curtis was eating lunch with a friend and the subject of happiness came up. Upon admitting he was not truly happy in life, the conversation turned towards him describing an ideal day. From here Curtis realized that the day of the lunch, for him, constituted such a day, which led to him deciding to write a film about ``how you achieve happiness in ordinary life''. Thinking that the concept was too ``simple'' he decided to add a time travel element to the film.