diff --git a/core/modules/datetime/lib/Drupal/datetime/Plugin/Field/FieldFormatter/DatetimeDefaultFormatter.php b/core/modules/datetime/lib/Drupal/datetime/Plugin/Field/FieldFormatter/DatetimeDefaultFormatter.php
index 532f0d6..2968ec2 100644
--- a/core/modules/datetime/lib/Drupal/datetime/Plugin/Field/FieldFormatter/DatetimeDefaultFormatter.php
+++ b/core/modules/datetime/lib/Drupal/datetime/Plugin/Field/FieldFormatter/DatetimeDefaultFormatter.php
@@ -126,8 +126,14 @@ public function viewElements(FieldItemListInterface $items) {
           'datatype' => 'xsd:dateTime',
         ),
       );
-    }
 
+      if (!empty($item->_attributes)) {
+        $elements[$delta]['#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);
+      }
+    }
     return $elements;
 
   }