coordinate clock
31Equinox — This article is about the astronomical event when the sun is at zenith over the Equator. For other uses, see Equinox (disambiguation). For the same event happening on other planets and setting up a celestial coordinate system, see Equinox… …
32Second — This article is about the unit of time. For other uses, see Second (disambiguation). A light flashing approximately once per second. The second (SI unit symbol: s; informal abbreviation: sec) is a unit of measurement of time, and is the… …
33Daylight saving time — This article is about daylight saving time in general. For DST in a specific location, see Daylight saving time by country. Summer time and DST redirect here. For other uses, see Summer time (disambiguation) and DST (disambiguation) …
34Coordinated Universal Time — UTC redirects here. For other uses, see UTC (disambiguation). Coordinated Universal Time (abbreviated UTC) is the primary time standard by which the world regulates clocks and time. It is one of several closely related successors to Greenwich… …
35Time zone — Timezone and TimeZone redirect here. For other uses, see Time zone (disambiguation). Local time redirects here. For the mathematical concept, see Local time (mathematics). This article is about time zones in general. For a list of time zones by… …
36Time signal — These automatic signal clocks were synchronized by telegraphy in 1905 before the widespread use of radio A time signal is a visible, audible, mechanical, or electronic signal used as a reference to determine the time of day. Contents 1 Audible… …
37System time — Unix date command In computer science and computer programming, system time represents a computer system s notion of the passing of time. In this sense, time also includes the passing of days on the calendar. System time is measured by a system… …
38Marine chronometer — Breguet twin barrel box chronometer. Classification Clock Industry Transportation …
39Tropical year — A tropical year (also known as a solar year), for general purposes, is the length of time that the Sun takes to return to the same position in the cycle of seasons, as seen from Earth; for example, the time from vernal equinox to vernal equinox,… …
40Prime Meridian — 0° Prime Meridian …
