The stardate of “The Trouble with Tribbles” is 4523.3.
That number appears in Captain Kirk’s opening log as the Enterprise responds to a distress call from Deep Space Station K-7. The episode is the fifteenth broadcast episode of Star Trek: The Original Series’ second season and first aired on December 29, 1967.
Stardates are Star Trek’s fictional dating system, not a direct equivalent to a conventional calendar date. Their meaning and progression were deliberately flexible in the original series, so 4523.3 should be treated as the episode’s stated in-universe date rather than converted precisely into a year or month.
The episode was written by David Gerrold and directed by Joseph Pevney. Its plot centers on tribbles multiplying aboard K-7 and the Enterprise while Klingon tensions rise around Sherman’s Planet. The story later received animated and Deep Space Nine follow-ups, including “Trials and Tribble-ations.”