public function getJsonValue()
    {
        $dts = $this->getDateTimes();
        $hasTime = $this->hasTime();
        $isFloating = $this->isFloating();

        $tz = $dts[0]->getTimeZone();
        $isUtc = $isFloating ? false : in_array($tz->getName(), ['UTC', 'GMT', 'Z']);

        return array_map(
            function (DateTimeInterface $dt) use ($hasTime, $isUtc) {
                if ($hasTime) {
                    return $dt->format('Y-m-d\\TH:i:s').($isUtc ? 'Z' : '');
                } else {
                    return $dt->format('Y-m-d');
                }
            },
            $dts
        );
    }