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 Belt Central Belt The Central Belt of Scotland is the area of highest population density within Scotland. It has a population of about 3.5 million covering an area of approximately 10,000 km, including Greater Glasgow, Ayrshire, Falkirk, Edinburgh, Lothian and Fife. Despite the name, it is not geographically central but is nevertheless situated at the 'waist' of Scotland on a conventional map and the term 'central' is used in many local government, police and NGO designations. It was formerly known as the Midlands or Scottish Midlands, but this term has fallen out of fashion. The Central Belt lies between the Highlands