src/Common/CreditCard.php
protected function setYearParameter($key, $value)
    {
        // normalize year to four digits
        if (null === $value || '' === $value) {
            $value = null;
        } else {
            $value = (int) gmdate('Y', gmmktime(0, 0, 0, 1, 1, (int) $value));
        }

        return $this->setParameter($key, $value);
    }
protected function setYearParameter($key, $value)
    {
        // normalize year to four digits
        if (null === $value || '' === $value) {
            $value = null;
        } else {
            $value = (int) gmdate('Y', gmmktime(0, 0, 0, 1, 1, (int) $value));
        }

        return $this->setParameter($key, $value);
    }
Set the credit card year.

The input value is normalised to a 4 digit number.

@param string $key Parameter key, e.g. 'expiryYear'
@param mixed $value Parameter value
@return $this