Geocentric Coordinate Time 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. It is equivalent to the proper time experienced by a clock at rest in a coordinate frame co-moving with the center of the Earth: that is, a clock that performs exactly the same movements as the Earth but is outside the Earth's gravity well. It is therefore not influenced by the gravitational time dilation caused by the Earth. TCG was
Summer term Summer term Summer term is the summer academic term at many British schools and universities and elsewhere in the world. In the UK, 'Summer term' runs from the Easter holiday until the end of the academic year in June or July, and thus corresponds to the Easter term at Cambridge University, and Trinity term at Oxford, Dublin and some other places. 'Summer term' is defined in some UK statutory instruments, such as the Education (Assessment Regulations) (Foundation to Key Stage 3) Order (Northern Ireland) 2007, which says: "summer term" means the period commencing immediately after the Easter holiday and ending