terrestrial time TT terrestrial dynamical time TDT ephemeris time
terrestrial_time%1:28:00:: tt%1:28:00:: terrestrial_dynamical_time%1:28:00:: tdt%1:28:00:: ephemeris_time%1:28:00::
(astronomy) a measure of time defined by Earth's orbital motion; terrestrial time is mean solar time corrected for the irregularities of the Earth's motions