protected function convertTs($str)
    {
        if (empty($str) || strlen($str) != 14) {
            return false;
        }
        $y = (int) substr($str, 0, 4);
        $m = (int) substr($str, 4, 2);
        $d = (int) substr($str, 6, 2);
        $h = (int) substr($str, 8, 2);
        $i = (int) substr($str, 10, 2);
        $s = (int) substr($str, 12, 2);

        $dt = new \DateTime();
        $dt->setTimezone(new \DateTimeZone('UTC'));
        $dt->setDate($y, $m, $d);
        $dt->setTime($h, $i, $s);

        return $dt->getTimestamp();
    }