From Greek Reporter:
One of the rarest sundials dating from the Greco-Roman period was found in Polichrono in Chalkidiki.This sundial is not a usual one as it shows the correct time at any given place.
It is noteworthy that in the Ancient Greek world, sundials consisted of a gnomon (indicator in Ancient Greek) in the form of a vertical post or peg set in a flat surface, upon which the shadow of the gnomon served to indicate the time.
This sundial has a surface which is separated in 12 parts representing 12 hours of the day. More particularly, the sundial consists of a hyperbola tracing the shadow’s path at the winter solstice, a second one for the summer solstice, and a straight east-west line in between marking the equinoctial shadows.
A line from the base of the gnomon to the south of the dial running due north denotes noontime. The hyperbola is centered on this noon line. The winter hyperbola opens to the north, the summer hyperbola to the south. In addition to the center noon line, additional oblique lines are added on either side to denote the hours of daylight before and after noon.
Archaeologist of the 16th Ephorate of Prehistoric and Classical Antiquities, Betina Tsigarida, specialist in the area of Chalkidiki, was the one to find the sundial and was given it as a reward for her work.
via: Old Sundial Found in Chalkidiki (Greek Reporter)