src/Money/DataMapper/Data/Money/Budget.php
public function addMonthToBitmask($month)
    {
        $month = (int) $month;
        if ($month < 1 || $month > 12) {
            throw new \RangeException('Month is invalid!');
        }

        $bit     = pow(2, $month - 1);
        $bitmask = $this->getMonthBitmask() | $bit;

        $this->setMonthBitmask($bitmask);

        return $this;
    }
public function addMonthToBitmask($month)
    {
        $month = (int) $month;
        if ($month < 1 || $month > 12) {
            throw new \RangeException('Month is invalid!');
        }

        $bit     = pow(2, $month - 1);
        $bitmask = $this->getMonthBitmask() | $bit;

        $this->setMonthBitmask($bitmask);

        return $this;
    }
Add month to bitmask

@param  int $month Month number (January: 1, February: 2, March: 3, April: 4...)
@return self