diff --git a/core/includes/bootstrap.inc b/core/includes/bootstrap.inc
index f74859e..0aeec35 100644
--- a/core/includes/bootstrap.inc
+++ b/core/includes/bootstrap.inc
@@ -88,7 +88,8 @@
  * @deprecated in Drupal 8.3.0, will be removed before Drupal 9.0.0.
  *   Use \Drupal::time()->getRequestTime();
  */
-define('REQUEST_TIME', (int) $_SERVER['REQUEST_TIME']);
+// Around the end of DST in the Pacific timezone.
+define('REQUEST_TIME', 1478422920);
 
 /**
  * Regular expression to match PHP function names.
diff --git a/core/lib/Drupal/Component/Datetime/Time.php b/core/lib/Drupal/Component/Datetime/Time.php
index 77da2e2..565ec2a 100644
--- a/core/lib/Drupal/Component/Datetime/Time.php
+++ b/core/lib/Drupal/Component/Datetime/Time.php
@@ -30,7 +30,8 @@ public function __construct(RequestStack $request_stack) {
    * {@inheritdoc}
    */
   public function getRequestTime() {
-    return $this->requestStack->getCurrentRequest()->server->get('REQUEST_TIME');
+    // Around the end of DST in the Pacific timezone.
+    return 1478422920;
   }
 
   /**