(at around 15 mins) Larry Stevens (Dick Powell) quips to his housekeeper, when she asks him if he needs his coat, "Don't you think love might keep me warm?" and winks. This is a nod to Powell's song in On the Avenue (1937).
The opera singer Melba, whose concert was robbed, is probably Australian soprano Dame Nellie Melba (1861-1931). Peach Melba and Melba toast are named for her.
Frank Capra initially purchased the film rights to the story, but upon entering the U.S. Army during World War II, he sold the rights to Arnold Pressburger.
A similar plot was the basis for the TV series Early Edition (1996), in which a man received the next day's newspaper and had 24 hours to prevent a calamity reported in the paper from occurring.