Day


Day
/day/, n.
1. Clarence (Shepard) /shep"euhrd/, 1874-1935, U.S. author.
2. Dorothy, 1897-1980, U.S. Roman Catholic social activist, journalist, and publisher.

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I
Time required for a celestial body to turn once on its axis; especially, the period of the Earth's rotation.

The sidereal day (see sidereal period) is the time required for the Earth to rotate once relative to the background of the stars (i.e., the time between two observed passages of a star over the same meridian of longitude). The apparent solar day is the time between two successive transits of the Sun over the same meridian. Because the orbital motion of the Earth makes the Sun seem to move slightly eastward each day relative to the stars, the solar day is about four minutes longer than the sidereal day. The mean solar day is the average value of the solar day, which changes slightly in length during the year as the Earth's speed in its orbit varies.
II
(as used in expressions)
All Saints' Day
All Souls' Day
April Fools' Day
All Fools' Day
D Day
Day Doris
Day Dorothy
Day Lewis Cecil
Hershey Alfred Day
Judgment Day of
Mother's Day and Father's Day
New Year's Day
O'Connor Sandra Day
Sandra Day
Saint Bartholomew's Day Massacre of
Six Day War
Valentine's Day
Reorganized Church of Jesus Christ of Latter Day Saints
Seven Days' Battles

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      time required for a celestial body to turn once on its axis; especially the period of the Earth's rotation. The sidereal day is the time required for the Earth to rotate once relative to the background of the stars—i.e., the time between two observed passages of a star over the same meridian of longitude. The apparent solar day is the time between two successive transits of the Sun over the same meridian. Because the orbital motion of the Earth makes the Sun seem to move slightly eastward each day relative to the stars, the solar day is about four minutes longer than the sidereal day; i.e., the mean solar day is 24 hours 3 minutes 56.555 seconds of mean sidereal time; more usually the sidereal day is expressed in terms of solar time, being 23 hours 56 minutes 4 seconds of mean solar time long. The mean solar day is the average value of the solar day, which changes slightly in length during the year as Earth's speed in its orbit varies.

      The solar day is the fundamental unit of time in both astronomical practice and civil life. It begins at midnight and runs through 24 hours, until the next midnight. A day is commonly divided into two sets of 12 hours for ordinary timekeeping purposes; those hours from midnight to noon are designated AM (ante meridiem, “before noon”), and those from noon to midnight are designated PM (post meridiem, “after noon”). In law the word day, unless qualified, means the 24 hours between midnight and midnight, rather than the daylight hours between sunrise and sunset.

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Universalium. 2010.

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  • day — W1S1 [deı] n ▬▬▬▬▬▬▬ 1¦(24 hours)¦ 2¦(not night)¦ 3¦(when you are awake)¦ 4¦(time at work)¦ 5¦(past)¦ 6¦(now)¦ 7¦(future)¦ 8 somebody s/something s day 9 Independence/election/Christmas etc day 10 five/three/ni …   Dictionary of contemporary English

  • day — [ deı ] noun *** 1. ) count one of the periods of time that a week is divided into, equal to 24 hours: We re going away for five days. The animals are kept inside for 14 hours a day. 24 hours a day (=during the whole of the day and night): The… …   Usage of the words and phrases in modern English

  • Day — (d[=a]), n. [OE. day, dai, dei, AS. d[ae]g; akin to OS., D., Dan., & Sw. dag, G. tag, Icel. dagr, Goth. dags; cf. Skr. dah (for dhagh ?) to burn. [root]69. Cf. {Dawn}.] 1. The time of light, or interval between one night and the next; the time… …   The Collaborative International Dictionary of English

  • Day — bezeichnet: Day (Sprache), eine Adamaua Sprache Orte in den Vereinigten Staaten: Day (Arkansas) Day Book (North Carolina) Day Center (New York) Day (Florida) Day Heights (Ohio) Day (Kalifornien) Day (Kentucky) Day (Louisiana) Day (Maryland) Day… …   Deutsch Wikipedia

  • day — /day/, n. 1. the interval of light between two successive nights; the time between sunrise and sunset: Since there was no artificial illumination, all activities had to be carried on during the day. 2. the light of day; daylight: The owl sleeps… …   Universalium

  • day — [dā] n. [ME dai < OE dæg (pl. dagas), akin to ON dagr, Goth dags, OHG tag < PGmc * dagwaz, prob. < IE base * ag̑hes, day, with d by assoc. with base * dhegwh , to burn] 1. a) the period of light between sunrise and sunset b) daylight c)… …   English World dictionary

  • day — ► NOUN 1) a period of twenty four hours as a unit of time, reckoned from midnight to midnight and corresponding to a rotation of the earth on its axis. 2) the time between sunrise and sunset. 3) (usu. days) a particular period of the past. 4)… …   English terms dictionary

  • day — [n1] light part of every 24 hours astronomical day, bright, dawn to dark, daylight, daytime, diurnal course, early bright, light, light of day, mean solar day, nautical day, sidereal day, sunlight, sunrise to sunset, sunshine, working day;… …   New thesaurus

  • Day 1 — redirects here. For other uses, see Day One (disambiguation). Day 1 Studio album by Robbie Nevil Released …   Wikipedia

  • day — s.m.inv. ES ingl. {{wmetafile0}} giorno in cui si verifica un avvenimento o si celebra una ricorrenza; posposto a un sostantivo e preceduto da un trattino forma lessemi s.m.inv.: compleanno day, matrimonio day, Giampaolo Rossi day {{line}}… …   Dizionario italiano


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