Geocentric Coordinate Time system. When the Earth is at perihelion in January, TCG ticks even more slowly than it does on average, due to gravitational time dilation from being deeper in the Sun's gravity well and also velocity time dilation from moving faster relative to the Sun. At aphelion in July the opposite holds, with TCG ticking faster than it does on average. Geocentric Coordinate Time Geocentric Coordinate Time (TCG - Temps-coordonnée géocentrique) is a coordinate time standard intended to be used as the independent variable of time for all calculations pertaining to precession, nutation, the Moon, and artificial satellites of the Earth.
Central Europe do not clearly define the region, but Encarta places the same countries into Central Europe in its individual articles on countries, adding Slovenia in "south central Europe". The German Encyclopaedia "Meyers Grosses Taschenlexikon" ("Meyers Big Pocket Encyclopedia"), 1999, defines Central Europe as the central part of Europe with no precise borders to the East and West. The term is mostly used to denominate the territory between the Schelde to Vistula and from the Danube to the Moravian Gate. Usually the countries considered to be Central European are Austria, Croatia, the Czech Republic, Germany, Hungary, Poland, Slovakia, Slovenia, Switzerland; in the