code: protected function getComponent($e)
      {
          // JD -> Date
          $ihmsf = [];
          IAU::D2dtf($this->timescale, $this->prec - 2, $this->jd, $this->dayFrac,
            $iy, $im, $id, $ihmsf);
  
          switch ($e) {
              case 'year':
                  return $iy;
  
              case 'month':
                  return $im;
  
              case 'day':
                  return $id;
  
              case 'hour':
                  return $ihmsf[0];
  
              case 'min':
                  return $ihmsf[1];
  
              case 'sec':
                  return $ihmsf[2];
  
              case 'micro':
                  return $ihmsf[3];
          }
      }
docs: Gets a component of this date
  
  @param  string $e Component name, e.g. year, month, etc...
  
  @return int|float