WARNING: The expressions below describe a prediction formulation
that is not recommended for operational use. The expressions will
continue to be provided in order to allow users to implement legacy
procedures. Users are encouraged to explore the possibility of
utilizing the tabular predictions available in the bulletin or in
electronic data files available from the IERS Rapid Service/Prediction
Center located at USNO.
Because of the lower quality of this model, the prediction accuracy
is a few mas to tens of mas worse than the published accuracy of the
prediction model.
x = 0.1255 + 0.0097 cos A - 0.0907 sin A + 0.0361 cos C + 0.0142 sin C
y = 0.3514 - 0.0813 cos A - 0.0117 sin A + 0.0142 cos C - 0.0361 sin C
UT1-UTC = -0.0123 - 0.00066 (MJD - 58438) - (UT2-UT1)
where A = 2*pi*(MJD-58430)/365.25 and C = 2*pi*(MJD-58430)/435.