Swat/SwatDate.php
public function subtractYears($years)
    {
        $years = (int) $years;
        $years = -$years;
        return $this->addYears($years);
    }
public function subtractYears($years)
    {
        $years = (int) $years;
        $years = -$years;
        return $this->addYears($years);
    }
public function subtractYears ( $ years ) { $ years = ( int ) $ years ; $ years = - $ years ; return $ this -> addYears ( $ years ) ; }
Subtracts the specified number of years from this date

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

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