diff --git a/buildings-start_date.json b/buildings-start_date.json
index a5b5055..007a3e0 100644
--- a/buildings-start_date.json
+++ b/buildings-start_date.json
@@ -45,7 +45,16 @@
         ],
         "description": [
             "{% if tags.start_date %}",
-            "{{ tags.start_date }}",
+            "{{ tags.start_date|osmFormatDate({ format: 'short' }) }}",
+            "{% else %}",
+            "{{ trans('unknown') }}",
+            "{% endif %}"
+        ],
+        "popupDescription": [
+            "{% if tags.start_date %}",
+            "{{ tags.start_date|osmFormatDate }}",
+            "{% else %}",
+            "{{ trans('unknown') }}",
             "{% endif %}"
         ],
         "markerSymbol": null,
diff --git a/detailsBody.html b/detailsBody.html
index 3c5a746..ca0b27f 100644
--- a/detailsBody.html
+++ b/detailsBody.html
@@ -145,7 +145,7 @@
   <li class='hasSymbol'>
    <i class="fa fa-clock-o" aria-hidden="true"></i>
    <span class='key'>{{ keyTrans('start_date') }}:</span>
-   <span class='value'>{{ enumerate(tags.start_date) }}</span>
+   <span class='value'>{{ tags.start_date|osmFormatDate }}</span>
   </li>
 {% endif %}
 
@@ -153,7 +153,7 @@
   <li class='hasSymbol'>
    <i class="fa fa-clock-o" aria-hidden="true"></i>
    <span class='key'>{{ keyTrans('opening_date') }}:</span>
-   <span class='value'>{{ enumerate(tags.opening_date) }}</span>
+   <span class='value'>{{ tags.opening_date|osmFormatDate }}</span>
   </li>
 {% endif %}
 
diff --git a/popupBody.html b/popupBody.html
index d278846..b3ead54 100644
--- a/popupBody.html
+++ b/popupBody.html
@@ -151,7 +151,7 @@
   <li class='hasSymbol'>
    <i class="fa fa-clock-o" aria-hidden="true"></i>
    <span class='key'>{{ keyTrans('start_date') }}:</span>
-   <span class='value'>{{ enumerate(tags.start_date) }}</span>
+   <span class='value'>{{ tags.start_date|osmFormatDate }}</span>
   </li>
 {% endif %}
 
@@ -159,7 +159,7 @@
   <li class='hasSymbol'>
    <i class="fa fa-clock-o" aria-hidden="true"></i>
    <span class='key'>{{ keyTrans('opening_date') }}:</span>
-   <span class='value'>{{ enumerate(tags.opening_date) }}</span>
+   <span class='value'>{{ tags.opening_date|osmFormatDate }}</span>
   </li>
 {% endif %}