diff --git a/core/modules/comment/comment.module b/core/modules/comment/comment.module
index 14df557..e9ac0f2 100644
--- a/core/modules/comment/comment.module
+++ b/core/modules/comment/comment.module
@@ -1712,6 +1712,10 @@ function template_preprocess_comment(&$variables) {
 
   // Gather comment classes.
   // 'published' class is not needed, it is either 'preview' or 'unpublished'.
+  
+  $variables['attributes']['data-date'] = array();
+  $variables['attributes']['data-date'][] = $comment->created->value;
+  
   if ($variables['status'] != 'published') {
     $variables['attributes']['class'][] = $variables['status'];
   }