fix: improve holiday name retrieval by comparing year, month, and day directly to avoid timezone issues

refactor: change exported variables to local scope in state management for better encapsulation

public/js/holidays.js

@@ -129,11 +129,16 @@ function getPublicHolidays(year, bundesland) {
  */
 function getHolidayName(date) {
   const year = date.getFullYear();
+  const month = date.getMonth();
+  const day = date.getDate();
+  
   const holidays = getPublicHolidays(year, currentBundesland);
   
-  const dateStr = date.toISOString().split('T')[0];
+  // Compare year, month, and day directly (avoid timezone issues)
   const holiday = holidays.find(h => {
-    return h.date.toISOString().split('T')[0] === dateStr;
+    return h.date.getFullYear() === year && 
+           h.date.getMonth() === month && 
+           h.date.getDate() === day;
   });
   
   return holiday ? holiday.name : null;