A clock, or a timepiece, is a device used to measure and indicate time. The clock is one of the oldest human inventions, meeting the need to measure intervals of time shorter than the natural units such as the day, the lunar month, and the year. Devices operating on several physical processes have been used over the millennia.
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.
Surface weather analysis is a special type of weather map that provides a view of weather elements over a geographical area at a specified time based on information from ground-based weather stations.
SMPTE timecode is a set of cooperating standards to label individual frames of video or film with a timecode. The system is defined by the Society of Motion Picture and Television Engineers in the SMPTE 12M specification. SMPTE revised the standard in 2008, turning it into a two-part document: SMPTE 12M-1 and SMPTE 12M-2, including new explanations and clarifications.
A radio clock or radio-controlled clock (RCC), and often (incorrectly) referred to as an atomic clock is a type of quartz clock or watch that is automatically synchronized to a time code transmitted by a radio transmitter connected to a time standard such as an atomic clock. Such a clock may be synchronized to the time sent by a single transmitter, such as many national or regional time transmitters, or may use the multiple transmitters used by satellite navigation systems such as Global Positioning System. Such systems may be used to automatically set clocks or for any purpose where accurate time is needed. RC clocks may include any feature available for a clock, such as alarm function, display of ambient temperature and humidity, broadcast radio reception, etc.
A clock face is the part of an analog clock that displays time through the use of a flat dial with reference marks, and revolving pointers turning on concentric shafts at the center, called hands. In its most basic, globally recognized form, the periphery of the dial is numbered 1 through 12 indicating the hours in a 12-hour cycle, and a short hour hand makes two revolutions in a day. A long minute hand makes one revolution every hour. The face may also include a second hand, which makes one revolution per minute. The term is less commonly used for the time display on digital clocks and watches.
An analog watch (American) or analogue watch is a watch whose display is not digital but rather analog with a traditional clock face. The name is an example of a retronym; it was coined to distinguish analog watches, which had simply been called "watches", from newer digital watches. It strictly refers to the design of the display, regardless of the timekeeping technology used within the watch movement or module, although its counterpart, "digital watch", usually connotes digital electronics in both. A digital watch is one in which the time is displayed as a series of digits, e.g. "04:32". An analog watch is one in which the display is not digital, but is indicated (typically) by the continuous motion of one, two, or three rotating pointers or hands pointing to numbers arrayed on a circular dial.
The Prague astronomical clock or Prague Orloj is a medieval astronomical clock attached to the Old Town Hall in Prague, the capital of the Czech Republic.
Seiko Group Corporation, commonly known as Seiko, is a Japanese maker of watches, clocks, electronic devices, semiconductors, jewelry, and optical products. Founded in 1881 by Kintarō Hattori in Tokyo, Seiko introduced the world's first commercial quartz wristwatch in 1969.
A chronograph is a specific type of watch that is used as a stopwatch combined with a display watch. A basic chronograph has an independent sweep second hand and a minute sub-dial; it can be started, stopped, and returned to zero by successive pressure on the stem. More complex chronographs use additional complications and can have multiple sub-dials to measure seconds, minutes, hours and even fractions of a second. In addition, many modern chronographs use moveable bezels as tachymeters for rapid calculations of speed or distance. Louis Moinet invented the chronograph in 1816 for use in tracking astronomical objects. Chronographs were also used heavily in artillery fire in the mid to late 1800s. More modern uses of chronographs involve aircraft piloting, auto racing, diving and submarine maneuvering.
In horology, a complication is any feature of a timepiece beyond the display of hours, minutes and seconds. A timepiece indicating only hours, minutes and seconds is known as a simple movement. Common complications include date or day-of-the-week indicators, alarms, chronographs (stopwatches), and automatic winding mechanisms. Complications may be found in any clock, but they are most notable in mechanical watches where the small size makes them difficult to design and assemble. A typical date-display chronograph may have up to 250 parts, while a particularly complex watch may have a thousand or more parts. Watches with several complications are referred to as grandes complications.
Geochron, Inc. is an American company founded in 1965 by James Kilburg, an inventor from Luxembourg. It is also the name of their flagship product, the Geochron Global Time Indicator. The Geochron was the first world clock to display day and night on a world map, showing the familiar "bell curve" of light and darkness. The Geochron employs an intricate analog clockwork mechanism for its display, that shows the month, date, day of the week, hours and minutes, the areas of the world currently experiencing day and night, and the meridian passage of the sun. The main display is dominated by a world map, with time zones prominently indicated. At the top of the map are arrows corresponding to each time zone. As each day progresses, the map is scrolled from left to right by gear mechanisms, and the arrows for each time zone shift their positions relative to a stationary band fixed at the top that has a horizontal series of numbers representing hours. The viewer may read the time by seeing what number his time zone's arrow is currently pointing to. The map is backlit, and a mechanism behind the map defines well-lit and shaded areas that are also stationary relative to the movement of the map. In this way, as time progresses, different areas are shown to be experiencing daytime and night. The center of the lit area lines up with the 12 noon on the stationary time strip. There is also a day-and-month readout below the map, and a minutes readout above.
A digital clock displays the time digitally, as opposed to an analogue clock.
Clocks and watches with a 24-hour analog dial have an hour hand that makes one complete revolution, 360°, in a day. The more familiar 12-hour analog dial has an hour hand that makes two complete revolutions in a day.
A diving watch, also commonly referred to as a diver's or dive watch, is a watch designed for underwater diving that features, as a minimum, a water resistance greater than 1.1 MPa (11 atm), the equivalent of 100 m (330 ft). The typical diver's watch will have a water resistance of around 200 to 300 m, though modern technology allows the creation of diving watches that can go much deeper. A true contemporary diver's watch is in accordance with the ISO 6425 standard, which defines test standards and features for watches suitable for diving with underwater breathing apparatus in depths of 100 m (330 ft) or more. Watches conforming to ISO 6425 are marked with the word DIVER'S to distinguish ISO 6425 conformant diving watches from watches that might not be suitable for actual scuba diving.
A mechanical watch is a watch that uses a clockwork mechanism to measure the passage of time, as opposed to quartz watches which function using the vibration modes of a piezoelectric quartz tuning fork, or radio watches, which are quartz watches synchronized to an atomic clock via radio waves. A mechanical watch is driven by a mainspring which must be wound either periodically by hand or via a self-winding mechanism. Its force is transmitted through a series of gears to power the balance wheel, a weighted wheel which oscillates back and forth at a constant rate. A device called an escapement releases the watch's wheels to move forward a small amount with each swing of the balance wheel, moving the watch's hands forward at a constant rate. The escapement is what makes the 'ticking' sound which is heard in an operating mechanical watch. Mechanical watches evolved in Europe in the 17th century from spring powered clocks, which appeared in the 15th century.
The Dreger Clock is a large town clock with 19 different dials and displays which tell the local (California) time, the time in 12 international cities, the phase of the moon, the date and day of the week. It was built between the years of 1928 and 1933 by Andrew Dreger, Sr., a German immigrant to the United States, who was a blacksmith and watchmaker. The clock stood in front of his home in Long Beach, California for almost 20 years, until his death. It was then moved to Knott's Berry Farm in Buena Park, California, where it was enjoyed by visitors for over 50 years. The clock underwent restoration during the years 2008 and 2009 and when restoration was complete it was placed in the Buena Park Historical District in front of the Whitaker-Jaynes house as a historical reminder of the city's early years. The clock was installed on September 25, 2009.
Quartz clocks and quartz watches are timepieces that use an electronic oscillator regulated by a quartz crystal to keep time. This crystal oscillator creates a signal with very precise frequency, so that quartz clocks and watches are at least an order of magnitude more accurate than mechanical clocks. Generally, some form of digital logic counts the cycles of this signal and provides a numerical time display, usually in units of hours, minutes, and seconds.
Windows Clock is a time management app for Microsoft Windows, with five key features: alarms, world clocks, timers, a stopwatch, and focus sessions. The features are listed on a sidebar. The app is similar in functionality and design to the Clock app on iOS. Windows Clock was available on mobile devices for over a decade before it was available on PCs with the introduction of Windows 8.1. Tiles for alarms, timers, and the stopwatch can be pinned to the Start menu. The latest version of the app uses the Universal Windows Platform APIs and adopts Windows UI theme. Windows Clock is distinct from the Windows taskbar's clock, which has been part of Windows since 1995.
The Casio AE-1000W is a quartz digital watch manufactured by Japanese electronics company Casio. The watch was introduced in 2010 in the "Youth Series" range of watches designed to attract young buyers. The watch is popular for its simple classic design, comfortable wearability and a host of features including world time for a low price. The AE-1000W has several other variations as part of the AE-series of watches in the Casio Youth Series.
