What is Solar time?
[[Image:Sidereal day (prograde).png|right|thumb|300px|On a [[Direct motion|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.]] '''Solar time''' is a calculation of the passage of time based on the position of the Sun in the sky. The fundamental unit of solar time is the [[synodic day]]. Traditionally, there are three types of time reckoning based on astronomical observations: '''apparent solar time''' and '''mean solar time''', and ''[[sidereal time]]'', which is based on the apparent motions of stars other than the Sun. ==Related pages== * [[Sidereal time]] * [[Solar calendar]] [[Category:Astronomy]] {{sci-stub}}