This function converts a Julian Date from the Barycentric Coordinate Timescale (TCB) to the Barycentric Dynamical Timescale (TDB) .

This is the inverse operation of calceph_time_jd_tdb_to_jd_tcb().

The conversion relies on the relation between TCB and TDB defined by the IAU 2006 Resolution B3 : "Re-definition of Barycentric Dynamical Time, TDB".

The input Julian Date is provided as two double-precision numbers (jd0_tcb and jdfrac_tcb). The converted date is stored in jd0_tdb and jdfrac_tdb.

If the ephemeris handle is NULL, the function returns an error.

The following example converts a TCB date to TDB:

t_calcephbin *peph;
double jd0_tcb = 2451545.0;
double jdfrac_tcb = 0.5;
double jd0_tdb, jdfrac_tdb;

/* open the ephemeris file */
peph = calceph_open("example_lsk.tls");
if (peph != NULL)
{
    /* Convert TCB to TDB */
    if (calceph_time_jd_tcb_to_jd_tdb(peph, jd0_tcb, jdfrac_tcb,
                                     &jd0_tdb, &jdfrac_tdb) != 0)
    {
        printf("TDB Date: %f + %f\n", jd0_tdb, jdfrac_tdb);
    }

    calceph_close(peph);
}