ISTWCMS-5214: adding theming needed for opportunity and also fixing dates

source/_patterns/04-components/card/card-elements/_header.twig

@@ -33,6 +33,16 @@
     } %}
   {% endif %}
 
+  {% if header.posted %}
+    {% include '@components/label/label.twig' with {
+      'label': 'Date posted'
+    } %}
+    {% include '@components/card/card-elements/_date.twig' with {
+      'date_format': 'long',
+      'date': header.posted
+    } %}
+  {% endif %}
+
   {% if header.opportunity_type %}
     {% include '@components/card/card-elements/_opportunity-type.twig' with {
       'opportunity_type': header.opportunity_type