One Day is based on the novel of the same name by David Nicholls, who also wrote the script.
In the film, Anne Hathaway stars as Emma, a working-class girl, who makes an agreement on the day of their graduation--July 15, 1988--with Dexter, a wealthy kid looking for fun, to meet on the same day every year to see where their lives have taken them. And for the next 20 years they meet on that one day for a front-row set to each other's life.
"She has a vast range that is extraordinary...He is very contemporary...he has an elegance and is laidback and confident." The film is "like 20 small films put together."