diff --git a/core/lib/Drupal/Core/Datetime/Element/DateElementBase.php b/core/lib/Drupal/Core/Datetime/Element/DateElementBase.php
index 12ab03b..b516249 100644
--- a/core/lib/Drupal/Core/Datetime/Element/DateElementBase.php
+++ b/core/lib/Drupal/Core/Datetime/Element/DateElementBase.php
@@ -3,6 +3,7 @@
 namespace Drupal\Core\Datetime\Element;
 
 use Drupal\Core\Datetime\DrupalDateTime;
+use Drupal\Core\Form\FormStateInterface;
 use Drupal\Core\Render\Element\FormElement;
 
 /**
@@ -69,4 +70,31 @@ protected static function datetimeRangeYears($string, $date = NULL) {
     return array($min_year, $max_year);
   }
 
+  /**
+   * Perform common element processing for date related form elements.
+   *
+   * @param array $element
+   *   The form element whose value is being processed.
+   * @param \Drupal\Core\Form\FormStateInterface $form_state
+   *   The current state of the form.
+   * @param array $complete_form
+   *   The complete form structure.
+   *
+   * @return array
+   *   The form element whose value has been processed.
+   */
+  public static function processDateElement(&$element, FormStateInterface $form_state, &$complete_form) {
+    // The value callback has populated the #value array.
+    $date = !empty($element['#value']['object']) ? $element['#value']['object'] : NULL;
+
+    // Set a fallback timezone.
+    if ($date instanceof DrupalDateTime) {
+      $element['#date_timezone'] = $date->getTimezone()->getName();
+    }
+    elseif (empty($element['#date_timezone'])) {
+      $element['#date_timezone'] = drupal_get_user_timezone();
+    }
+
+    return $element;
+  }
 }
diff --git a/core/lib/Drupal/Core/Datetime/Element/Datelist.php b/core/lib/Drupal/Core/Datetime/Element/Datelist.php
index ba8f6ba..2661ccf 100644
--- a/core/lib/Drupal/Core/Datetime/Element/Datelist.php
+++ b/core/lib/Drupal/Core/Datetime/Element/Datelist.php
@@ -25,6 +25,7 @@ public function getInfo() {
         array($class, 'validateDatelist'),
       ),
       '#process' => array(
+        array($class, 'processDateElement'),
         array($class, 'processDatelist'),
       ),
       '#theme' => 'datetime_form',
@@ -183,14 +184,6 @@ public static function processDatelist(&$element, FormStateInterface $form_state
     // The value callback has populated the #value array.
     $date = !empty($element['#value']['object']) ? $element['#value']['object'] : NULL;
 
-    // Set a fallback timezone.
-    if ($date instanceof DrupalDateTime) {
-      $element['#date_timezone'] = $date->getTimezone()->getName();
-    }
-    elseif (empty($element['#date_timezone'])) {
-      $element['#date_timezone'] = drupal_get_user_timezone();
-    }
-
     $element['#tree'] = TRUE;
 
     // Determine the order of the date elements.
diff --git a/core/lib/Drupal/Core/Datetime/Element/Datetime.php b/core/lib/Drupal/Core/Datetime/Element/Datetime.php
index 3015e2d..779f3f2 100644
--- a/core/lib/Drupal/Core/Datetime/Element/Datetime.php
+++ b/core/lib/Drupal/Core/Datetime/Element/Datetime.php
@@ -44,6 +44,7 @@ public function getInfo() {
         array($class, 'validateDatetime'),
       ),
       '#process' => array(
+        array($class, 'processDateElement'),
         array($class, 'processDatetime'),
         array($class, 'processGroup'),
       ),
@@ -217,14 +218,6 @@ public static function processDatetime(&$element, FormStateInterface $form_state
     // The value callback has populated the #value array.
     $date = !empty($element['#value']['object']) ? $element['#value']['object'] : NULL;
 
-    // Set a fallback timezone.
-    if ($date instanceof DrupalDateTime) {
-      $element['#date_timezone'] = $date->getTimezone()->getName();
-    }
-    elseif (empty($element['#date_timezone'])) {
-      $element['#date_timezone'] = drupal_get_user_timezone();
-    }
-
     $element['#tree'] = TRUE;
 
     if ($element['#date_date_element'] != 'none') {