nextcloud/apps/calendar/ajax/settings/gettimezonedetection.php

<?php
/**
 * Copyright (c) 2011, 2012 Georg Ehrke <ownclouddev at georgswebsite dot de>
 * This file is licensed under the Affero General Public License version 3 or
 * later.
 * See the COPYING-README file.
 */
 
OC_JSON::checkLoggedIn();
OC_JSON::checkAppEnabled('calendar');
OC_JSON::success(array('detection' => OC_Preferences::getValue(OCP\USER::getUser(), 'calendar', 'timezonedetection')));