After filming was done, Eric Bana started filming Star Trek (2009), a role which required him to shave his head. However re-shoots for The Time Traveler's Wife (2009) were needed, but production was put on hold so Eric's hair could grow out. It took so long that the movie's release date was pushed back by nearly a year.
This is the third movie in which Rachel McAdams stars as the love interest of a time traveler. The other ones are About time (2013), in which she played the titular wife to Domhnall Gleeson's character and Midnight in Paris (2011), in which she played the fiancée of Owen Wilson's character.
The trivia item below may give away important plot points.
During the final meadow scene, after Henry disappears, Alba bends down to pick up his discarded brown loafers. This is a reference to the cover art of one edition of the book, which features a young girl (visible only from mid-leg down) standing next to a brown pair of loafers in a field.