The Equation of Time is the difference between the time determined by a sundial and the clock time. It is due to the obliquity of the Earth's axis and the unequal motion of the Earth (ellipse). The value, computed for 12:00 UT, is between 14 :20 min (near Feb 12) and +16:24 min (near Nov 4).

Equation
of time and length of solar day:
(for
2001)











































































Equation of Time
Length of Solar Day

Equation of Time (Royal Greenwich Observatory Information Leaflet) 