code: public function toJD($scale = null)
      {
          if ($scale) {
              return bcadd((string)$this->jd, (string)$this->dayFrac, $scale);
          } else {
              return $this->jd + $this->dayFrac;
          }
      }
docs: Returns a Julian date representation of this instance.
  
  @param  int $scale Optional additional decimal precision
  
  @return float|string