mean solar day


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mean solar day

n.
The period of time between two successive transits of the mean sun, used as the standard in measuring the 24-hour day.

mean solar day

n
(Astronomy) the time between two successive passages of the mean sun across the meridian at noon. It is equal to 24 hours 3 minutes and 56.555 seconds of mean sidereal time

day

(deɪ)

n.
1. the interval of light between two successive nights; the time between sunrise and sunset.
2. the light of day; daylight.
3.
a. Also called mean solar day. a division of time equal to 24 hours and representing the average length of the period during which the earth makes one rotation on its axis.
b. Also called solar day. a division of time equal to the time elapsed between two consecutive returns of the same terrestrial meridian to the sun.
c. a division of time equal to 24 hours but reckoned from one midnight to the next.
4. an analogous division of time for a planet other than the earth: the Martian day.
5. the portion of a day allotted to work: an eight-hour day.
6. (often cap.) a day having a particular purpose or observance: New Year's Day.
7. a time considered as propitious or opportune: His day will come.
8. Often, days. a particular era: in olden days.
9. Usu., days. period of life or activity: His days are numbered.
10. period of existence or influence; heyday: In my day we called them “hepcats.”
11. the contest or battle at hand: to win the day.
Idioms:
1. call it a day, to stop working for the rest of the day.
2. day in, day out, every day without fail; regularly. Also, day in and day out.
[before 950; Middle English; Old English dæg]

mean solar day

A measure of time representing the interval between consecutive passages of the Sun across the meridian, averaged over one year. 1 day = 24 hr (86,400 sec).
ThesaurusAntonymsRelated WordsSynonymsLegend:
Noun1.mean solar day - time for Earth to make a complete rotation on its axismean solar day - time for Earth to make a complete rotation on its axis; "two days later they left"; "they put on two performances every day"; "there are 30,000 passengers per day"
time unit, unit of time - a unit for measuring time periods
tomorrow - the day after today; "what are our tasks for tomorrow?"
today - the day that includes the present moment (as opposed to yesterday or tomorrow); "Today is beautiful"; "did you see today's newspaper?"
yesterday - the day immediately before today; "it was in yesterday's newspapers"
morrow - the next day; "whenever he arrives she leaves on the morrow"
eve - the day before; "he always arrives on the eve of her departure"
date, day of the month - the specified day of the month; "what is the date today?"
date - a particular day specified as the time something happens; "the date of the election is set by law"
daylight, daytime, day - the time after sunrise and before sunset while it is light outside; "the dawn turned night into day"; "it is easier to make the repairs in the daytime"
high noon, midday, noon, noonday, noontide, twelve noon - the middle of the day
night, nighttime, dark - the time after sunset and before sunrise while it is dark outside
60 minutes, hour, hr - a period of time equal to 1/24th of a day; "the job will take more than an hour"
References in periodicals archive ?
The 24-hour mean solar day is the period between successive occasions when the sun is directly overhead.
Since 1820, the mean solar day has increased by about 2.5 milliseconds," he said.
The mean solar day length is a constant 24 hours throughout the year.