How to get full end day on calendar?

Question

I have my events to display except that the event does not go until the end date, it stops 1 day before... I tried with the nextDayThreshold and nothing, the format of my dates is as follows: Y-m-d

any idea so that I can include the end date on the display of my events?

foreach ($dateEvent as $event) {
    $getDate = $this->wpBookingdatesRepository->findBy(['booking_id' => $event->getBookingId()]);

    if (count($getDate) === 2) {
        $dates[] = [
            "title" => "",
            "start" => $getDate[0]->getBookingDate()->format('Y-m-d'),
            "end" => $getDate[1]->getBookingDate()->format('Y-m-d'),
            "color" => "#f50202",
            "display" => "background"
        ];
    } elseif (count($getDate) === 1) {
        $dates[] = [
            "title" => "",
            "start" => $getDate[0]->getBookingDate()->format('Y-m-d'),
            "color" => "#f50202",
            "display" => "background"
        ];
    }
}

My api was generated with symfony in PHP

events: 'devis/date/api',

ThresholdnextDay and try to set date to format Y-m-dTH:i:s