Sidereal
(Redirected from Sidereal time)
Sidereal time measures the earth's movement relative to fixed stars rather than the sun.
Similar to solar time, sidereal time measures the earth's movement rather than a fixed increment of seconds. A mean sidereal day is 23 hours, 56 minutes, 4.0916 seconds, slightly shorter than a mean solar day.
Watches that measure sidereal time generally use a full sub-dial with hour and minute hands on a 24-hour scale. In contrast, solar time is generally displayed with an arrow, since it varies more or less than the calculated length of a day.
