// Zunächst aktuelle Werte bestimmen
$day = date("j");
$month = date("m");
$year = date("Y");
 
// Neuen EWert generieren mit gewünschter Zeit und um 1 erhöhtem Tag
$newtime = mktime(4, 0, 0, $month, $day+1, $year);

// Aktuelle Zeit des Servers
$aktuelleZeit = date("Y-m-d H:i:s");
// Zeitzone des Servers
$serverZeitzone = date_default_timezone_get();

<?php
$aktuelleZeit = date("d.m.Y H:i:s");
$serverZeitzone = date_default_timezone_get();
echo "Aktuelle Zeit des Servers: ".$aktuelleZeit."<br/>";
echo "Zeitzone des Servers: ".$serverZeitzone."<br/>";
 
echo date("d.m.Y H:i",mktime(0,0,0,2,22,2024)) . "<br>";
echo date("d.m.Y H:i",mktime(4,0,0,5,16,2024)) . "<br>";
 
$day = date("j");
$month = date("m");
$year = date("Y");
$newtime = mktime(4, 0, 0, $month, $day+1, $year);
echo "Soll 4:00 Uhr morgen früh sein: ".date("d.m.Y H:i",$newtime);
?>

            // Cookies
            // Determine current date
            $currentday = date("j");
            $currentmonth = date("m");
            $currentyear = date("Y");
           
            // Generate new value with desired time and day increased by 1
            $midnight = mktime(1, 0, 0, $currentmonth, $currentday+1, $currentyear);
            if ($surveyActive && $this->aSurveyInfo['usecookie'] == "Y") {
                if (!$oSurvey->getHasTokensTable()) {
                    setcookie("LS_" . $this->iSurveyid . "_STATUS", "COMPLETE", $midnight); //Cookie will expire at midnight
                }
            }