protected function extractNumberAndGetPosition($datetimeToParse, &$position)
    {
        $characters = str_split($datetimeToParse);

        $number = '';
        $numberStarted = false;
        foreach ($characters as $index => $character) {
            if (ord($character) >= 48 && ord($character) <= 57) {
                if (!$numberStarted) {
                    $numberStarted = true;
                    $position = $index;
                }
                $number .= $character;
            } elseif ($numberStarted) {
                return $number;
            }
        }

        if ($numberStarted) {
            return $number;
        }

        throw new Exception\InvalidParseStringException('Expected number not found in the string.', 1280498431);
    }