reclique_gxp_sync.module

<?php

use Drupal\Component\Datetime\DateTimePlus;

/**
 * Modify the schedules search results prior output.
 */
function reclique_gxp_sync_openy_repeat_results_alter(&$result, $request) {
  // Dynamically generate Sign Up links (pass event's date to url.)
  $site_timezone = \Drupal::config('system.date')->get('timezone.default');
  foreach ($result as $item) {
    if (empty($item->register_url)) {
      continue;
    }
    if (!empty($item->time_start_calendar)) {
      $date = DateTimePlus::createFromFormat('Y-m-d H:i:s', $item->time_start_calendar, $site_timezone)
        ->setTimezone(new \DateTimeZone('UTC'))
        ->format('Y-m-d');

      $item->register_url = preg_replace('/DATE_PLACEHOLDER/', $date, $item->register_url);
    }
  }
}