<Tr> <Td> </Td> <Td> This article may contain an excessive amount of intricate detail that may only interest a specific audience . Please help by spinning off or relocating any relevant information, and removing excessive detail that may be against Wikipedia's inclusion policy . (May 2015) (Learn how and when to remove this template message) </Td> </Tr> <P> Earth's rotation period relative to the Sun (its mean solar day) consists of 86,400 seconds of mean solar time, by definition . Each of these seconds is slightly longer than an SI second because Earth's solar day is now slightly longer than it was during the 19th century, due to tidal deceleration . The mean solar second between 1750 and 1892 was chosen in 1895 by Simon Newcomb as the independent unit of time in his Tables of the Sun . These tables were used to calculate the world's ephemerides between 1900 and 1983, so this second became known as the ephemeris second . The SI second was made equal to the ephemeris second in 1967 . </P> <P> Earth's rotation period relative to the fixed stars, called its stellar day by the International Earth Rotation and Reference Systems Service (IERS), is 86164.098 903 691 seconds of mean solar time (UT1) (23 56 4.098 903 691). Earth's rotation period relative to the precessing or moving mean vernal equinox, its sidereal day, is 86164.090 530 832 88 seconds of mean solar time (UT1) (23 56 4.090 530 832 88). Thus the sidereal day is shorter than the stellar day by about 8.4 ms . The length of the mean solar day in SI seconds is available from the IERS for the periods 1623--2005 and 1962--2005 . Recently (1999--2005) the average annual length of the mean solar day in excess of 86400 SI seconds has varied between 0.3 ms and 1 ms, which must be added to both the stellar and sidereal days given in mean solar time above to obtain their lengths in SI seconds . </P> <Table> <Tr> <Th> Celestial objects </Th> <Th_colspan="2"> Rotation period </Th> </Tr> <Tr> <Td> Sun </Td> <Td> 25.379995 days (Carrington rotation) 35 days (high latitude) </Td> <Td> 25d 9h 7m 11.6 s 35d </Td> </Tr> <Tr> <Td> Mercury </Td> <Td> 58.6462 days </Td> <Td> 58d 15h 30m 30s </Td> </Tr> <Tr> <Td> Venus </Td> <Td>--243.0187 days </Td> <Td> − 243d 0h 26m </Td> </Tr> <Tr> <Td> Earth </Td> <Td> 0.99726968 days </Td> <Td> 0d 23h 56m 4.0910 s </Td> </Tr> <Tr> <Td> Moon </Td> <Td> 27.321661 days (synchronous toward Earth) </Td> <Td> 27d 7h 43m 11.5 s </Td> </Tr> <Tr> <Td> Mars </Td> <Td> 1.02595675 days </Td> <Td> 1d 0h 37m 22.663 s </Td> </Tr> <Tr> <Td> Ceres </Td> <Td> 0.37809 days </Td> <Td> 0d 9h 4m 27.0 s </Td> </Tr> <Tr> <Td> Jupiter </Td> <Td> 0.4135344 days (deep interior) 0.41007 days (equatorial) 0.41369942 days (high latitude) </Td> <Td> 0d 9h 55m 29.37 0d 9h 50m 30s 0d 9h 55m 43.63 s </Td> </Tr> <Tr> <Td> Saturn </Td> <Td> 0.44403 days (deep interior) 0.426 days (equatorial) 0.443 days (high latitude) </Td> <Td> 0d 10h 39m 24s 0d 10h 14m 0d 10h 38m </Td> </Tr> <Tr> <Td> Uranus </Td> <Td> − 0.71833 days </Td> <Td> − 0d 17h 14m 24s </Td> </Tr> <Tr> <Td> Neptune </Td> <Td> 0.67125 days </Td> <Td> 0d 16h 6m 36s </Td> </Tr> <Tr> <Td> Pluto </Td> <Td> − 6.38718 days (synchronous with Charon) </Td> <Td>--6d 9h 17m 32s </Td> </Tr> <Tr> <Td> Haumea </Td> <Td> 0.163145 days </Td> <Td> 0d 3h 54m 56s </Td> </Tr> </Table>

Time taken to complete rotation on its axis of earth