J2000.0 epoch: January 1, 2000, 12:00 TT (Terrestrial Time)
This is the standard reference epoch for modern astronomical calculations.
Most ephemeris formulas and coordinate transformations are calibrated to this epoch.
Constant
See
"Astronomical Algorithms" by Jean Meeus, Chapter 21
J2000.0 epoch: January 1, 2000, 12:00 TT (Terrestrial Time)
This is the standard reference epoch for modern astronomical calculations. Most ephemeris formulas and coordinate transformations are calibrated to this epoch.