standard time

standard time
the civil time officially adopted for a country or region, usually the civil time of some specific meridian lying within the region. The standard time zones in the U.S. (Atlantic time, Eastern time, Central time, Mountain time, Pacific time, Yukon time, Alaska-Hawaii time, and Bering time) use the civil times of the 60th, 75th, 90th, 105th, 120th, 135th, 150th, and 165th meridians respectively, the difference of time between one zone and the next being exactly one hour. See diag. under time zone.
[1880-85, Amer.]

* * *

Official local time of a region or country.

Local mean solar time depends on longitude; it advances by four minutes per degree eastward. The Earth can thus be divided into 24 standard time zones, each approximately 15° in longitude. The actual boundaries of each time zone are determined by local authorities and in many places deviate considerably from 15°. The times in different zones usually differ by an integral number of hours; minutes and seconds are the same. See also Greenwich Mean Time.

* * *

      the time of a region or country that is established by law or general usage as civil time.

      The concept of standard time was adopted in the late 19th century in an attempt to end the confusion that was caused by each community's use of its own solar time. Some such standard became increasingly necessary with the development of rapid railway (railroad) transportation and the consequent confusion of schedules that used scores of different local times kept in separate communities. (Local time varies continuously with change in longitude.) The need for a standard time was felt most particularly in the United States and Canada, where long-distance railway routes passed through places that differed by several hours in local time. Sir Sandford Fleming (Fleming, Sir Sandford), a Canadian railway planner and engineer, outlined a plan for worldwide standard time in the late 1870s. Following this initiative, in 1884 delegates from 27 countries met in Washington, D.C., and agreed on a system basically the same as that now in use.

 The present system employs 24 standard meridians of longitude (lines running from North Pole to South Pole, at right angles to the Equator) 15° apart, starting with the prime meridian (Greenwich meridian) through Greenwich, England. These meridians are theoretically the centres of 24 standard time zones (time zone) (as illustrated in the Figure—>), although in practice the zones often are subdivided or altered in shape for the convenience of inhabitants; a notable example of such alteration is the eastward extension of the International Date Line around the Pacific island country of Kiribati. Time is the same throughout each zone and differs from the international basis of legal and scientific time, Coordinated Universal Time, by an integral number of hours; minutes and seconds are the same. In a few regions, however, the legal time kept is not that of one of the 24 standard time zones because half-hour or quarter-hour differences are in effect there. In addition, Daylight Saving Time is a common system by which time is advanced one hour from standard, typically to extend daylight hours during conventional waking time and in most cases for part of the year (usually in summer).
 

* * *


Universalium. 2010.

Игры ⚽ Нужно сделать НИР?

Look at other dictionaries:

  • Standard time — is the result of synchronizing clocks in different geographical locations within a time zone to the same time rather than using the local meridian as in local mean time or solar time. The time so set has come to be defined in terms of offsets… …   Wikipedia

  • Standard time — Time Time, n.; pl. {Times}. [OE. time, AS. t[=i]ma, akin to t[=i]d time, and to Icel. t[=i]mi, Dan. time an hour, Sw. timme. [root]58. See {Tide}, n.] 1. Duration, considered independently of any system of measurement or any employment of terms… …   The Collaborative International Dictionary of English

  • standard time — Time measured by a standard adapted to mean solar time to convenient use in commerce, business and the ordinary affairs of life, the country being divided into time zones, each zone having as an accepted time, the actual sun time at the middle… …   Ballentine's law dictionary

  • standard time — UK US noun [U] ► MEASURES the time that is officially used in a country or an area of a country: »In the fall, staff get paid an hour overtime during the return to standard time. → Compare DAYLIGHT SAVING TIME(Cf. ↑daylight saving time), GMT(Cf.… …   Financial and business terms

  • Standard Time — (Einheitszeit in den Vereinigten Staaten von Amerika). Bis Ende 1883 rechneten die Eisenbahnen der Vereinigten Staaten eine jede für ihr Netz nach Ortszeit. Die hieraus bei der großen Ausdehnung der einzelnen Eisenbahnnetze hervorgehenden… …   Enzyklopädie des Eisenbahnwesens

  • standard time — ☆ standard time n. 1. the time in any of the 24 time zones, each an hour apart, into which the earth is divided: it is based on distance east or west of Greenwich, England; the 8 zones of North America (Atlantic, Eastern, Central, Mountain,… …   English World dictionary

  • standard time — n [U] the time to which all clocks in a particular area of the world are set …   Dictionary of contemporary English

  • standard time — standard ,time noun uncount the official time in a country or region …   Usage of the words and phrases in modern English

  • standard time — noun the official time in a local region (adjusted for location around the Earth); established by law or custom • Syn: ↑civil time, ↑local time • Hypernyms: ↑time • Hyponyms: ↑Atlantic Time, ↑A …   Useful english dictionary

  • standard\ time — • ST • standard time • slow time noun Clock time that is set by law or agreement in a country or in part of a country; especially, in the United States: the clock time used between fall and spring, which is an hour slower than the time used in… …   Словарь американских идиом

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”