diff --git a/layouts/posts/list.html b/layouts/posts/list.html
index bdce83c..e7b9d88 100644
--- a/layouts/posts/list.html
+++ b/layouts/posts/list.html
@@ -7,7 +7,7 @@
       {{ $month := (print .Key "-01") }}
       <h3 class="mt-5">
         {{ if ne .Key "0001-01" }}
-          {{ dateFormat "2006-01" $month }}
+          <time class="posts-archive-month" datetime="{{ $month }}">{{ dateFormat "2006-01" $month }}</time>
         {{ end }}
       </h3>
       {{ range .Pages.ByDate }}