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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...mean solar time
(Encyclopedia)mean solar time: see solar time. ...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...mean
(Encyclopedia)mean, in statistics, a type of average. The arithmetic mean of a group of numbers is found by dividing their sum by the number of members in the group; e.g., the sum of the seven numbers 4, 5, 6, 9, 1...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 ...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 meridian
(Encyclopedia)Greenwich meridian: see prime meridian. ...Greenwich Village
(Encyclopedia)Greenwich Village grĕnˈĭch [key], residential district of lower Manhattan, New York City, extending S from 14th St. to Houston St. and W from Washington Square to the Hudson River. North of the mai...ephemeris time
(Encyclopedia)ephemeris time (ET), astronomical time defined by the orbital motions of the earth, moon, and planets. The earth does not rotate with uniform speed, so the solar day is an imprecise unit of time. Ephe...Browse by Subject
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