Clock

A clock (from the Latin cloca, "bell") is an instrument for measuring time. A clock is usually a physical instrument; an especially accurate one is called a chronometer. The clock in its modern form (24 hour clock) has been in use since at least the 14th century. Clock can refer to an abstract system of time measurement (see calendar for other measurements). Modern clocks define constant units of time: an hour is always sixty minutes, of sixty seconds each.

Specific types of clocks

• alarm clock
• analog clock with digital display
• astronomical clock
• atomic clock
• binary clock
• bracket clock
• cartel clock
• chiming clock
• clock network
• Data clock for timescapes created with time-technology
• doll's head clock
• Railroad chronometers
• countdown clock
• cuckoo clock
• game clock
• grandfather clock
• hourglass
• longcase clock
• mantel clock
• pedestal clock
• swinging pendulum clock
• torsion pendulum clock
• projection clock
• quartz clock
• sidereal clock
• skeleton clock
• stopwatch
• striking clock
• sundial
• tide clock
• time clock
• watch
• water clock
• world clock