What is the exact time in which earth complete 1 rotation on its axis ?
The sidereal day is 23 hours, 56 minutes, and 4 seconds. That is the time it takes Earth to make 1 full rotation. It is the speed at which a telescope tracks the stars, since the stars are effectively at infinity and to not appear to move in the sky. The sun “appears” to move in the sky due to the orbit of the earth around the sun, so the time it takes for the earth’s orbit to complete an orbit relative to the “moving target” of the sun is 24 hours exactly (by original definition). Edit: JOHNNIE’s answer is misleading because it fails to mention the fact that there are only 364.25 rotations in a year of 365.25 days. The extra day comes from the single orbit of the earth around the sun, which would produce 1 day per year even if the earth did not rotate at all. If you calculate 364.25 orbits per 365.25 days, and convert to hours, minutes, and seconds, you will get 23 hours, 56 minutes, and 3.4 seconds. That’s slightly off from the exact figure because it’s not exactly 365.25 days in a y
