diff --git a/core/modules/system/templates/time.html.twig b/core/modules/system/templates/time.html.twig
index 8a2c2d4..521df56 100644
--- a/core/modules/system/templates/time.html.twig
+++ b/core/modules/system/templates/time.html.twig
@@ -25,9 +25,4 @@
  * @see http://www.w3.org/TR/html5-author/the-time-element.html#attr-time-datetime
  */
 #}
-{%
-  set classes = [
-    'datetime',
-  ]
-%}
-<time{{ attributes.addClass(classes) }}>{{ html ? text|raw : text }}</time>
+<time{{ attributes.addClass('datetime') }}>{{ html ? text|raw : text }}</time>