public static function generateIsoTime()
    {
        $date = \Carbon\Carbon::now(self::getTimeZone());
        date_default_timezone_set(self::getTimeZone());
        $fmt     = $date->format('Y-m-d\TH:i:s');
        $ISO8601 = sprintf("$fmt.%s%s", substr(microtime(), 2, 3), date('P'));

        return $ISO8601;
    }