page_title: Watch
section_title: Functions
hierarchical_section_title: Watch / Functions
caption_attribution_description: Deutsch: Armbanduhr von Breguet. English: Breguet watch. Français&#160;: Montre Breguet.
context_page_description: A watch is a portable timepiece intended to be carried or worn by a person. It is designed to keep a consistent movement despite the motions caused by the person's activities. A wristwatch is designed to be worn around the wrist, attached by a watch strap or other type of bracelet, including metal bands, leather straps or any other kind of bracelet. A pocket watch is designed for a person to carry in a pocket, often attached to a chain. The study of timekeeping is known as horology.
  Watches progressed in the 17th century from spring-powered clocks, which appeared as early as the 14th century. During most of its history the watch was a mechanical device, driven by clockwork, powered by winding a mainspring, and keeping time with an oscillating balance wheel. These are called mechanical watches. In the 1960s the electronic quartz watch was invented, which was powered by a battery and kept time with a vibrating quartz crystal. By the 1980s the quartz watch had taken over most of the market from the mechanical watch. Historically, this is called the quartz revolution.
context_section_description: Customarily, watches provide the time of day, giving at least the hour and minute, and often the second. Many also provide the current date, and some (called "complete calendar" or "triple date" watches) display the day of the week and the month as well. However, many watches also provide a great deal of information beyond the basics of time and date. Some watches include alarms. Other elaborate and more expensive watches, both pocket and wrist models, also incorporate striking mechanisms or repeater functions, so that the wearer could learn the time by the sound emanating from the watch. This announcement or striking feature is an essential characteristic of true clocks and distinguishes such watches from ordinary timepieces. This feature is available on most digital watches.
  A complicated watch has one or more functions beyond the basic function of displaying the time and the date; such a functionality is called a complication. Two popular complications are the chronograph complication, which is the ability of the watch movement to function as a stopwatch, and the moonphase complication, which is a display of the lunar phase. Other more expensive complications include Tourbillon, Perpetual calendar, Minute repeater, and Equation of time. A truly complicated watch has many of these complications at once (see Calibre 89 from Patek Philippe for instance). Some watches can both indicate the direction of Mecca and have alarms that can be set for all daily prayer requirements. Among watch enthusiasts, complicated watches are especially collectible. Some watches include a second 12-hour or 24-hour display for UTC or GMT.
  The similar-sounding terms chronograph and chronometer are often confused, although they mean altogether different things. A chronograph is a watch with an added duration timer, often a stopwatch complication (as explained above), while a chronometer watch is a timepiece that has met an industry standard test for performance under pre-defined conditions: a chronometer is a high quality mechanical or a thermo-compensated movement that has been tested and certified to operate within a certain standard of accuracy by the COSC (Contrôle Officiel Suisse des Chronomètres). The concepts are different but not mutually exclusive; so a watch can be a chronograph, a chronometer, both, or neither.
  Many computerized wristwatches have been developed, but none have had long-term sales success, because they have awkward user interfaces due to the tiny screens and buttons, and short battery life. As miniaturized electronics became cheaper, watches have been developed containing calculators, tonometers, barometers, altimeters, a compass using both hands to show the N/S direction, video games, digital cameras, keydrives, GPS receivers and cellular phones. A few astronomical watches show phase of the Moon and other celestial phenomena. In the early 1980s Seiko marketed a watch with a television in it. Such watches have also had the reputation as unsightly and thus mainly geek toys. Several companies have however attempted to develop a computer contained in a wristwatch (see also wearable computer).
  Electronic sports watches, combining timekeeping with GPS and/or activity tracking, address the general fitness market and have the potential for commercial success (Garmin forerunner, Garmin Vivofit, Epson, announced model of Swatch Touch series).
  Braille watches have analog displays with raised bumps around the face to allow blind users to tell the time. Their digital equivalents use synthesised speech to speak the time on command.
caption: A Breguet squelette watch 2933 with tourbillon
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