In A Busy Day, a wife (played by an energetic Charlie Chaplin) becomes jealous of her husband's interest in another woman during a military parade. On her way to attack the couple, the wife interrupts the set of a film, knocking over a film director and a police officer. Finally, the husband pushes the wife off a pier and she falls into the harbor.

According to the 1965 book The Films of Charlie Chaplin, this is the first film in which Chaplin plays a woman. He used the wardrobe of fellow Keystone player Alice Davenport.

This short film (half a reel) was shot near San Pedro Harbor in less than two hours. One can see interesting glimpses of American naval ships in the background. The other part of the reel is an educational short titled The Morning Papers.