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Greenwich mean time
(Encyclopedia)Greenwich mean time or Greenwich meridian time (GMT), the former name for mean solar time at the site of the Royal Observatory in Greenwich, England, which is located on the prime meridian. In 1925 th...universal time
(Encyclopedia)universal time (UT), the international time standard common to every place in the world, it nominally reflects the mean solar time along the earth's prime meridian (renumbered to equate to civil time)...solar time
(Encyclopedia)solar time, time defined by the position of the sun. The solar day is the time it takes for the sun to return to the same meridian in the sky. Local solar time is measured by a sundial. When the cente...civil time
(Encyclopedia)civil time, local time based on universal time. Civil time may be formally defined as mean solar time plus 12 hr; the civil day begins at midnight, while the mean solar day begins at noon. Civil time ...mean solar time
(Encyclopedia)mean solar time: see solar time. ...prime meridian
(Encyclopedia)prime meridian, meridian that is designated zero degree (0°) longitude, from which all other longitudes are measured. By international convention, it passes through the site of the Royal Observatory ...standard time
(Encyclopedia)standard time, civil time used within a given time zone. The earth is divided into 24 time zones, each of which is about 15° of longitude wide and corresponds to one hour of time. Within a zone all c...Greenwich, borough, Greater London, England
(Encyclopedia)Greenwich grĭnˈīj, grĕnˈ– [key], inner borough of Greater London, SE England, on the Thames River. ...Dyson, Sir Frank Watson
(Encyclopedia)Dyson, Sir Frank Watson dīˈsən [key], 1868–1939, English astronomer, b. Ashby-de-la-Zouch, grad. Cambridge. He was astronomer royal of Scotland (1905–10) and of England (from 1910). As director...Greenwich, town, United States
(Encyclopedia)Greenwich grĕnˈĭch [key], residential town (2020 pop. 63,518), Fairfield co., SW Conn., on ...Browse by Subject
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