During the course of the year, the time as read from a sundial can run ahead of clock time by as much as 16 min 33 s (around October 31–November 1) or fall behind by as much as 14 min 6 s (around February 11–12). This difference, known as the equation of time, results from an apparent irregular movement of the Sun caused by a combination of the obliquity of the Earth's rotation axis and the eccentricity of its orbit. The equation of time is visually illustrated by an analemma.
change
Thanks, Ivan.
According to a Wikipedia article:
During the course of the year, the time as read from a sundial can run ahead of clock time by as much as 16 min 33 s (around October 31–November 1) or fall behind by as much as 14 min 6 s (around February 11–12). This difference, known as the equation of time, results from an apparent irregular movement of the Sun caused by a combination of the obliquity of the Earth's rotation axis and the eccentricity of its orbit. The equation of time is visually illustrated by an analemma.I've changed this blog entry to match.