In what film did the actors mistakenly wear wristwatches?

This is a classic film trivia question! The film is "The Time Machine" (1960).

The mistake? The characters are supposed to be traveling through time, centuries into the future. However, the actors are all wearing wristwatches, a technology that wouldn't have existed in the futuristic setting of the film.

This detail is often overlooked but is a fun little slip-up for those who are paying attention!