diff --git a/templates/content/external-entity--linkedevents-event.html.twig b/templates/content/external-entity--linkedevents-event.html.twig
index 710cf39aa..95279af4b 100644
--- a/templates/content/external-entity--linkedevents-event.html.twig
+++ b/templates/content/external-entity--linkedevents-event.html.twig
@@ -1,28 +1,26 @@
-{% set is_multidate = start_timestamp|date('Y-m-d') != end_timestamp|date('Y-m-d') %}
-{% set same_year = start_timestamp|date('Y') == end_timestamp|date('Y') %}
-{% set html_start = start_timestamp|format_date('custom', 'Y-m-d') ~ 'T' ~ start_timestamp|format_date('custom', 'H:i') %}
-{% set html_end = end_timestamp|format_date('custom', 'Y-m-d') ~ 'T' ~ end_timestamp|format_date('custom', 'H:i') %}
-
-{% if is_multidate and not same_year %}
-  {% set card_start_timestamp = start_timestamp|date('d.m.Y')%}
-  {% set card_end_timestamp = end_timestamp|date('d.m.Y')%}
-{% elseif is_multidate %}
-  {% set card_start_timestamp = start_timestamp|date('d.m.')%}
-  {% set card_end_timestamp = end_timestamp|date('d.m.Y')%}
-{% else %}
-  {% set card_start_timestamp = start_timestamp|format_date('publication_date_format') %}
-  {% set card_end_timestamp = end_timestamp|format_date('custom', 'H:i') %}
+{% if start_timestamp and end_timestamp is not null %}
+  {% set is_multidate = start_timestamp|date('Y-m-d') != end_timestamp|date('Y-m-d') %}
+  {% set same_year = start_timestamp|date('Y') == end_timestamp|date('Y') %}
+  {% set card_start_timestamp = is_multidate and not same_year
+    ? start_timestamp|date('d.m.Y')
+    : is_multidate
+    ? start_timestamp|date('d.m.')
+    : start_timestamp|format_date('publication_date_format') %}
+  {% set card_end_timestamp = is_multidate
+    ? end_timestamp|date('d.m.Y')
+    : end_timestamp|format_date('custom', 'H:i') %}
+  {% set html_start = start_timestamp|format_date('custom', 'Y-m-d') ~ 'T' ~ start_timestamp|format_date('custom', 'H:i') %}
+  {% set html_end = end_timestamp|format_date('custom', 'Y-m-d') ~ 'T' ~ end_timestamp|format_date('custom', 'H:i') %}
 {% endif %}
 
-
 {% embed '@hdbt/component/card-teaser.twig' with {
   card_image: content.main_image,
   card_title: content.external_link[0]['#title'],
   card_url: content.external_link[0]['#url'],
-  card_has_start_and_end: true,
-  card_start_timestamp: card_start_timestamp,
-  card_end_timestamp: card_end_timestamp,
-  card_html_start: html_start,
-  card_html_end: html_end,
+  card_has_start_and_end: start_timestamp and end_timestamp is not null,
+  card_start_timestamp: card_start_timestamp|default(null),
+  card_end_timestamp: card_end_timestamp|default(null),
+  card_html_start: html_start|default(null),
+  card_html_end: html_end|default(null),
 } %}
 {% endembed %}