code: def tdb(self, year=None, month=1, day=1, hour=0, minute=0, second=0.0,
              jd=None):
          
          if jd is not None:
              tdb = jd
          else:
              tdb = julian_date(
                  _to_array(year), _to_array(month), _to_array(day),
                  _to_array(hour), _to_array(minute), _to_array(second),
              )
          tdb = _to_array(tdb)
          tt = tdb - tdb_minus_tt(tdb) / DAY_S
          t = Time(self, tt)
          t.tdb = tdb
          return t
docs: Build a `Time` from a TDB calendar date.
  
          Supply the Barycentric Dynamical Time (TDB) as a proleptic
          Gregorian calendar date:
  
          >>> t = ts.tdb(2014, 1, 18, 1, 35, 37.5)
          >>> t.tdb
          2456675.56640625