Planetary Science

What is the exact length of one earth day?

Answer

Wiki User
08/20/2012

One Earth rotation relative to a star besides the sun (often measured by Polaris), stellar time, takes approximately 23 hours, 56 minutes, and 4 seconds. One Earth rotation relative to the vernal equinox (sidereal time) is takes approximately 23 hours, 56 minutes, and 4.091 seconds. Earth's rotation relative to the sun's (Sol) apparent position in the sky (solar time) appears to change with the month, varying as much as 30 seconds.