A clock, also known as a timepiece, was a stationary device used to keep track of the passage of time. They were used in many cultures. The inner workings of a mechanical timepiece was known as clockwork. Time, when displayed on a clock, was said to be __ o'clock.
In 2121, Henry Archer kept a clock on a wall in his home on Earth. (ENT: "Broken Bow")
By 2151, clocks were used on the Akaali homeworld. Garos kept several small and larger ones in his curio shop. (ENT: "Civilization")
By the 23rd century, clocks were used aboard starships in the form of on-board chronometers. (TOS: "The Corbomite Maneuver", "The Naked Time", "Balance of Terror", "Tomorrow is Yesterday", "The Mark of Gideon") Chronometer function could be disrupted by many things, such as the non-application of natural laws of the universe, causing stoppage (TAS: "The Magicks of Megas-Tu") or the reversal of time, causing them to run backward (TAS: "The Counter-Clock Incident").
In the remastered version of "The Naked Time", Sulu's chronometer featured a stardate clock and the 24-hour clock.
Colonel West said that if hostilities with the Klingon Empire developed in 2293, the Federation was in a position to "clean their chronometers." (Star Trek VI: The Undiscovered Country)
James T. Kirk kept an antique clock in his home during his first retirement from Starfleet. Sometime prior to 2293, he gave the clock to his friend, Leonard McCoy. (Star Trek Generations)
An internal clock was an individual's automatic time regulation system based on daily cycles. (TNG: "Time Squared")
Marla Aster kept an old clock with a large base in her house on Earth. (TNG: "The Bonding")
Doctor Noonien Soong kept a cuckoo clock in his laboratory on Terlina III. (TNG: "Brothers")
On occasion, starships may need to reset the ship's clock, i.e., on-board chronometer, at which time a Federation time beacon or a realignment subspace signal by a starbase may be consulted. (TNG: "Clues", "Cause And Effect")
Soong-type androids such as Data had an internal chronometer. (TNG: "Schisms") The Intrepid-class starship USS Voyager also had internal chronometers. (VOY: "Relativity")
While under the influence of the Saltah'na energy sphere, Benjamin Sisko built a complex mechanical clock, the Saltah'na clock, which he would keep in his office in perpetuity. When asked later why he had done so, he replied "I have no idea." (DS9: "Dramatis Personae")
In an alternate timeline Jake Sisko owned two clocks in his house in Louisiana. One was placed on the wall next to the door and a larger grandfather clock, located in his living room. (DS9: "The Visitor")
An unknown humanoid culture in the Delta Quadrant used timepieces or tracking time. The display featured three sets of digits which relayed rotations, intervals, and fractions, the method of which the culture tracked time. (VOY: "Time and Again")
The call sheet listed this prop as "burned clock".
Captain Kathryn Janeway kept a high wooden clock in her quarters aboard Voyager. (VOY: "Eye of the Needle")
When Kathryn Janeway and Tuvok were taken to the Q Continuum, a building they were led to had a clock without hands. (VOY: "Death Wish")