public function monthDiff($date1, $date2){

                    $date1 = new \DateTime($date1);
                    $date2 = new \DateTime($date2);
                    $interval = $date1->diff($date2);
                    $months = ($interval->y * 12) + $interval->m;

                    return $months+1;


              }


              
              $inputData['quantity']= $this->monthDiff( " 2020-12-01", "2023-12-01");