diff --git a/View/Element/Html/Calendar.php b/View/Element/Html/Calendar.php
--- a/View/Element/Html/Calendar.php	2024-06-16 18:50:33
+++ b/View/Element/Html/Calendar.php	2024-06-16 18:50:33
@@ -111,8 +111,8 @@
         $this->assignFieldsValues($localeData);
 
         // get "am" & "pm" words
-        $this->assign('am', $this->encoder->encode($localeData['calendar']['gregorian']['AmPmMarkers']['0']));
-        $this->assign('pm', $this->encoder->encode($localeData['calendar']['gregorian']['AmPmMarkers']['1']));
+        $this->assign('am', $this->encoder->encode($localeData['calendar']['gregorian']['AmPmMarkers']['0'] ?? null));
+        $this->assign('pm', $this->encoder->encode($localeData['calendar']['gregorian']['AmPmMarkers']['1'] ?? null));
 
         // get first day of week and weekend days
         $this->assign(