diff --git a/src/templates/article.html b/src/templates/article.html
index 0b6010a..4b6844a 100644
--- a/src/templates/article.html
+++ b/src/templates/article.html
@@ -16,7 +16,7 @@
       <div class="navbar-brand">
         <a class="navbar-item" href="{article_overview_url}">
           <strong>{article_language_flag} {article_title}</strong>
-          <span>{article_datetime}</span>
+          <time datetime="{article_datetime_iso}">{article_datetime}</time>
         </a>
       </div>
     </nav>
diff --git a/src/templates/overview_card.html b/src/templates/overview_card.html
index 1acb645..3d896a9 100644
--- a/src/templates/overview_card.html
+++ b/src/templates/overview_card.html
@@ -5,7 +5,7 @@
             <p class="content">
                 {article_preview}
                 <br />
-                <time>{article_datetime}</time>
+                <time datetime="{article_datetime_iso}">{article_datetime}</time>
             </p>
         </div>
     </a>
diff --git a/stsg/build.py b/stsg/build.py
index c5d5211..d162364 100644
--- a/stsg/build.py
+++ b/stsg/build.py
@@ -87,6 +87,7 @@ class ArticleTranslation:
             "article_slug": self.article_overview.slug,
             "article_title": self.title,
             "article_datetime": self.article_overview.article_written.strftime(config.formatting.datetime_format),
+            "article_datetime_iso": self.article_overview.article_written.isoformat(),
             "article_language_name": self.language_name,
             "article_language_code": self.language_code,
             "article_language_flag": self.language_flag,
@@ -178,6 +179,7 @@ class ArticleOverview:
             "article_title": self.slug,
             "article_slug": self.slug,
             "article_datetime": self.article_written.strftime(config.formatting.datetime_format),
+            "article_datetime_iso": self.article_written.isoformat(),
             "article_overview_url": self.url,
             "article_overview_cards": self.overview_cards,
         }