Astronomers use sidereal time to track the movement of stars.
A sidereal day is approximately 23 hours, 56 minutes, and 4 seconds.
A sidereal year is the time it takes for Earth to complete one orbit around the Sun relative to the fixed stars.
A sidereal month is the time it takes for the Moon to complete one orbit around Earth relative to the fixed stars.
Sidereal astrology uses the actual positions of the stars in the sky to make predictions.