diff --git a/theme/templates/article.html.nunj b/theme/templates/article.html.nunj
index 37c928db8f02bc9fef1c1ed526cbb94a696e4ab5..8c85d551ecd968ccf1bbc20a78f6166959445f69 100644
--- a/theme/templates/article.html.nunj
+++ b/theme/templates/article.html.nunj
@@ -3,7 +3,7 @@
 {% block head %}
 
   <meta property="og:type" content="article" />
-  <meta property="article:published_time" content="{{ metadata.date.creation }}" />
+  <meta property="article:published_time" content="{{ metadata.date.creation | date }}" />
   {% if metadata.image %} <meta property="og:image" content="{{ metadata.image | absURL( canonicalURL ) }}" /> {% endif %}
   <meta property="og:description" content="{% if metadata.perex %}{{metadata.perex}}{% else %}{% if metadata.perex_e %}{{metadata.perex_e | truncate}}{% else %}{% if content %}{{ content | striptags | truncate }}{% endif %}{% endif %}{% endif %}" />