Swat/SwatDate.php
public function addYears($years)
    {
        $years = (int) $years;
        $interval = new DateInterval('P' . abs($years) . 'Y');

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

        return $this->add($interval);
    }
public function addYears($years)
    {
        $years = (int) $years;
        $interval = new DateInterval('P' . abs($years) . 'Y');

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

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

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

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