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