Sidereal day

A sidereal day is the time it takes for Earth to complete one full rotation (360 degrees) relative to distant stars, approximately 23 hours and 56 minutes. Unlike the conventional 24-hour solar day, which is based on the Sun's position, the sidereal day accounts for Earth's orbit around the Sun. Because Earth moves along its orbit, it must rotate a little extra (about 4 minutes) for the Sun to appear at the same position in the sky again, making the sidereal day slightly shorter than the solar day.