This episode takes place in 1944. Along with Star Trek: Assignment: Earth (1968) (which takes place in 1968), this is one of only two "Star Trek" episodes to take place entirely in the 20th century. Furthermore, both episodes take place mostly in and around New York City.
This episode is the second time that a character from the past mistakes a character from the future for a naval officer due to their affiliation with the Enterprise, the first being Edith Keeler and Dr. McCoy in "The City on the Edge of Forever".
John Fleck (Silik) also played Taibak in TNG "The Mind's Eye", a Cardassian Overseer in DS9 "The Homecoming", Ornithar in DS9 "The Search part 1", Koval in DS9 "Inter Arma Enim Silent Leges" and Abaddon in Voyager "Alice".