terrestrial dynamical time

[LouriscreAdumb]

(astronomy) a measure of time defined by Earths orbital motion; terrestrial time is mean solar time corrected for the irregularities of the Earths motions

[rekha patel]

Terrestrial Dynamical Time (TDT) is a time scale representing time experienced on the surface of the Earth to a high precision, in terms of atomic time rather than celestial motion. It was used in astronomical computations, primarily for predicting the positions of celestial bodies, until it was replaced by Terrestrial Time. It is used to account for the variances in the Earths rotation, such as irregularities and slowdowns, for more accurate timekeeping. TDT expresses time as counted on the hypothetical, perfectly uniform atomic time scale rather than as observed by an actual observer on the rotating Earth.