Epoch of The Day
In addition to its usual application concerning a reference point for long term astronomical calculations, the term Epoch has also been used to refer to the time of the beginning of the day.
In ordinary usage, the civil day is reckoned by the midnight epoch, that is, the civil day begins at midnight. In older astronomical usage, it was usual, until 1 January 1925, to reckon by a noon epoch, 12 hours after the start of the civil day of the same denomination, so that the day began when the mean sun crossed the meridian at noon.
In traditional cultures and in antiquity other epochs were used. In ancient Egypt days were reckoned from sunrise to sunrise, following a morning epoch. It has been suggested that this may be related to the fact that the Egyptians regulated their year by the heliacal rising of the star Sirius, a phenomenon which occurs in the morning just before dawn.
In cultures following a lunar or lunisolar calendar, in which the beginning of the month is determined by the appearance of the New Moon in the evening, the beginning of the day was reckoned from sunset to sunset, following an evening epoch. This practice was followed in the Jewish and Islamic calendars and in Medieval Western Europe in reckoning the dates of religious festivals.
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Famous quotes containing the words the day, epoch of, epoch and/or day:
“This could be the day.
I could slip anchor and wander
to the end of the jetty
uncoil into the waters
a vessel of light moonglade
ride the freshets to sundown”
—Audre Lorde (1934–1992)
“The death of a dear friend, wife, brother, lover, which seemed nothing but privation, somewhat later assumes the aspect of a guide or genius; for it commonly operates revolutions in our way of life, terminates an epoch of infancy or of youth which was waiting to be closed, breaks up a wonted occupation, or a household, or style of living, and allows for the formation of new ones more friendly to the growth of character.”
—Ralph Waldo Emerson (1803–1882)
“The death of a dear friend, wife, brother, lover, which seemed nothing but privation, somewhat later assumes the aspect of a guide or genius; for it commonly operates revolutions in our way of life, terminates an epoch of infancy or of youth which was waiting to be closed, breaks up a wonted occupation, or a household, or style of living, and allows the formation of new ones more friendly to the growth of character.”
—Ralph Waldo Emerson (1803–1882)
“The day is not purer than the depths of my heart.”
—Jean Racine (1639–1699)