Index: vendor/magento/framework/View/Element/Html/Calendar.php
IDEA additional info: Fixxes missing am/pm markers for time "https://github.com/magento/magento2/commit/144b491c7720a983c33c7c20b1f77ccd559c1031"
Subsystem: com.intellij.openapi.diff.impl.patch.CharsetEP
<+>UTF-8
===================================================================
diff --git a/vendor/magento/framework/View/Element/Html/Calendar.php b/vendor/magento/framework/View/Element/Html/Calendar.php
--- a/vendor/magento/framework/View/Element/Html/Calendar.php	
+++ b/vendor/magento/framework/View/Element/Html/Calendar.php	(date 1731398760432)
@@ -111,8 +111,7 @@
         $this->assignFieldsValues($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']));
+        $this->assignAmPmWords($localeData);
 
         // get first day of week and weekend days
         $this->assign(
@@ -209,4 +208,23 @@
             $this->assign('week', $this->encoder->encode($localeData['fields']['week']['dn']));
         }
     }
+
+    /**
+     * Assign "am" & "pm" words from the ICU data
+     *
+     * @param \ResourceBundle $localeData
+     */
+    private function assignAmPmWords(\ResourceBundle $localeData): void
+    {
+        // AmPmMarkers and AmPmMarkersAbbr aren't guaranteed to exist, so fallback to null if neither exist
+        $amWord = $localeData['calendar']['gregorian']['AmPmMarkers'][0] ??
+            $localeData['calendar']['gregorian']['AmPmMarkersAbbr'][0] ??
+            null;
+        $pmWord = $localeData['calendar']['gregorian']['AmPmMarkers'][1] ??
+            $localeData['calendar']['gregorian']['AmPmMarkersAbbr'][1] ??
+            null;
+
+        $this->assign('am', $this->encoder->encode($amWord));
+        $this->assign('pm', $this->encoder->encode($pmWord));
+    }
 }