Swat/SwatDate.php
public function addMonths($months)
    {
        $months = (int) $months;
        $interval = new DateInterval('P' . abs($months) . 'M');

        if ($months < 0) {
            $interval->invert = 1;
        }

        return $this->add($interval);
    }
public function addMonths($months)
    {
        $months = (int) $months;
        $interval = new DateInterval('P' . abs($months) . 'M');

        if ($months < 0) {
            $interval->invert = 1;
        }

        return $this->add($interval);
    }
public function addMonths ( $ months ) { $ months = ( int ) $ months ; $ interval = new DateInterval ( 'P' . abs ( $ months ) . 'M' ) ; if ( $ months < 0 ) { $ interval -> invert = 1 ; } return $ this -> add ( $ interval ) ; }
Adds the specified number of months to this date

@param integer $months the number of months to add.

@return this object on success or false on failure.
Adds the specified number of months to this date