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.
Umbrella term term, by itself, gives little detail about the things that it describes or the relationships between them, but it is easy to say and remember. Blanket terms may originate as slang but eventually become integrated into the general vocabulary. Umbrella term An umbrella term is a popular metaphorical phrase that covers a wide range of concepts belonging to a common category. For example, "cryptology" is an umbrella term that encompasses cryptography and cryptanalysis, among other fields. Similarly, an umbrella organization is a central and coordinating body representing a number of smaller, separate bodies. A blanket term is a closely related