apparent solar day

American  

noun

Astronomy.

1. the period of time between two successive passages of the sun's center across the same meridian.

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Etymology

Origin of apparent solar day

First recorded in 1910–15

Example Sentences

After the invention of mechanical clocks that run at a uniform rate, it became necessary to abandon the apparent solar day as the fundamental unit of time.

From Textbooks • Oct. 13, 2016

The exact length of an apparent solar day varies slightly during the year.

From Textbooks • Oct. 13, 2016

The mean solar days are all exactly the same length; they are equal to the length of the average apparent solar day; and they are each four minutes longer than a sidereal day.

From The Astronomy of the Bible An Elementary Commentary on the Astronomical References of Holy Scripture by Maunder, E. Walter (Edward Walter)

This is the most natural and the most accurate measure of time for the navigator at sea and the unit of time adopted by the mariner is the apparent solar day.

From Lectures in Navigation by Draper, Ernest Gallaudet

The sidereal day and the mean solar day necessitate some means of registering time, such as clocks; therefore the original day in use must have been the apparent solar day.

From The Astronomy of the Bible An Elementary Commentary on the Astronomical References of Holy Scripture by Maunder, E. Walter (Edward Walter)