Place it as the payoff at the end of a waiting montage, once the clock reaches four, then follow it with a shocked reaction to sell the reveal and keep the edit moving.
Über diesen Sound
This short spoken clip announces that it is four o'clock in a clear, matter-of-fact voice, stretching the simple time check across just over seven seconds. The plain delivery makes it feel dryly funny and oddly suspenseful, as if an ordinary moment is being treated like a major event. It works best when the hour itself is the joke.