Solar time

calculation of elapsed time by the apparent position of the sun
(Redirected from Solar day)

Solar time relates to the amount of time which has passed according to orbit of the sun. A solar day is the amount of time it takes an object to go around the sun.

On a prograde planet like the Earth, the sidereal day is shorter than the solar day. At time 1, the Sun and a certain distant star are both overhead. At time 2, the planet has rotated 360° and the distant star is overhead again (1→2 = one sidereal day). But it is not until a little later, at time 3, that the Sun is overhead again (1→3 = one solar day). Or more simply, 1-2 is a complete rotation of the Earth. However because the Earth moving around the Sun affects the angle the Sun hits a position on the Earth, 1-3 is how long it takes noon to happen again.

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