Return offset between UTC and TAI palDat
This routine converts the MJD argument to calendar date before calling the SOFA/ERFA eraDat function.
This routine matches the slaDat interface which differs from the eraDat interface. Consider coding directly to the SOFA/ERFA interface.
See eraDat for a description of error conditions when calling this function with a time outside of the UTC range.
The status argument from eraDat is ignored. This is reasonable since the error codes are mainly related to incorrect calendar dates when calculating the JD internally.