This is the third movie in which Rachel McAdams stars as the love interest of a time traveler. The previous ones were The Time Traveler's Wife (2009), in which she played the titular wife to Eric Bana's character and Midnight in Paris (2011), in which she played the fiancée of Owen Wilson's character.
Rory towards the end of the film is reading the book 'Trash' which is Curtis's next film (Curtis wrote the screenplay for both Trash and About Time)
Zooey Deschanel was originally cast as Mary but dropped out due to scheduling conflicts and Rachel McAdams was cast.
Tim describes his mother more like a 'Bernard' than a 'Mary'. Richard Curtis always tries to include a Bernard character in his movies. The inspiration comes from Bernard Jenkin, the Tory MP for North Essex and former shadow defense secretary. Mr Jenkin's wife, is a former girlfriend of the Richard Curtis.
The US release date is the same as director Richard Curtis' birthday (November 8th).