diff -u b/core/modules/datetime/src/Plugin/Field/FieldFormatter/DateTimeDefaultFormatter.php b/core/modules/datetime/src/Plugin/Field/FieldFormatter/DateTimeDefaultFormatter.php
--- b/core/modules/datetime/src/Plugin/Field/FieldFormatter/DateTimeDefaultFormatter.php
+++ b/core/modules/datetime/src/Plugin/Field/FieldFormatter/DateTimeDefaultFormatter.php
@@ -86,18 +86,16 @@
       }
 
       // Display the date using theme datetime.
-      $elements[$delta] = [
+      $elements[$delta][] = [
         '#cache' => [
           'contexts' => [
             'timezone',
           ],
         ],
-        [
-          '#theme' => 'time',
-          '#text' => $output,
-          '#html' => FALSE,
-          '#attributes' => ['datetime' => $iso_date],
-        ],
+        '#theme' => 'time',
+        '#text' => $output,
+        '#html' => FALSE,
+        '#attributes' => ['datetime' => $iso_date],
       ];
 
       // Append on the end date.
@@ -111,16 +109,17 @@
               'timezone',
             ],
           ],
-          [
-            '#theme' => 'time',
-            '#text' => $output2,
-            '#html' => FALSE,
-            '#attributes' => ['datetime' => $iso_date2],
-          ],
+          '#theme' => 'time',
+          '#text' => $output2,
+          '#html' => FALSE,
+          '#attributes' => ['datetime' => $iso_date2],
         ];
       }
       if (!empty($item->_attributes)) {
-        $elements[$delta]['#attributes'] += $item->_attributes;
+        $elements[$delta][0]['#attributes'] += $item->_attributes;
+        if ($this->getFieldSetting('enddate_get') && !empty($output2)) {
+          $elements[$delta][2]['#attributes'] += $item->_attributes;
+        }
         // Unset field item attributes since they have been included in the
         // formatter output and should not be rendered in the field template.
         unset($item->_attributes);