diff --git a/backend/src/tools/statistik/routes.js b/backend/src/tools/statistik/routes.js
index 0ad8e80..d5203f7 100644
--- a/backend/src/tools/statistik/routes.js
+++ b/backend/src/tools/statistik/routes.js
@@ -132,14 +132,18 @@ router.get('/overview', authenticate, (req, res) => {
 
   function getBucketKey(dateStr) {
     if (!dateStr) return null;
-    const d = dateStr.slice(0, 10);
+    const d = dateStr.slice(0, 10); // YYYY-MM-DD, immer lokal
     if (granularity === 'day')   return d;
     if (granularity === 'week') {
-      // ISO-Woche: Montag der Woche
-      const dt = new Date(d);
-      const day = dt.getDay() || 7;
+      // Montag der Woche – rein mit String-Arithmetik (kein UTC-Bug)
+      const [y, m, dd] = d.split('-').map(Number);
+      const dt = new Date(y, m - 1, dd); // lokaler Konstruktor
+      const day = dt.getDay() || 7;      // 1=Mo … 7=So
       dt.setDate(dt.getDate() - day + 1);
-      return dt.toISOString().slice(0,10);
+      const py = dt.getFullYear();
+      const pm = String(dt.getMonth() + 1).padStart(2, '0');
+      const pd = String(dt.getDate()).padStart(2, '0');
+      return `${py}-${pm}-${pd}`;
     }
     return d.slice(0, 7); // YYYY-MM
   }
@@ -171,6 +175,26 @@ router.get('/overview', authenticate, (req, res) => {
     buckets[key].expenses += e.amount;
   }
 
+  // Leere Buckets auffüllen – lokaler Date-Konstruktor um UTC-Bug zu vermeiden
+  if (from || to) {
+    const parseLocal = s => { const [y,m,d] = s.split('-').map(Number); return new Date(y, m-1, d); };
+    const fmtLocal = dt => {
+      const y = dt.getFullYear(), m = String(dt.getMonth()+1).padStart(2,'0'), d = String(dt.getDate()).padStart(2,'0');
+      return `${y}-${m}-${d}`;
+    };
+    const firstBucket = Object.keys(buckets).sort()[0];
+    const startD = parseLocal(from || firstBucket || to);
+    const endD   = parseLocal(to   || fmtLocal(new Date()));
+    const cur = new Date(startD);
+    while (cur <= endD) {
+      const key = getBucketKey(fmtLocal(cur));
+      if (key && !buckets[key]) buckets[key] = { month:key, revenue:0, base_cost:0, expenses:0, orders:0 };
+      if (granularity === 'day')        cur.setDate(cur.getDate() + 1);
+      else if (granularity === 'week')  cur.setDate(cur.getDate() + 7);
+      else                              cur.setMonth(cur.getMonth() + 1);
+    }
+  }
+
   // Sortiert + ohne Filter auf letzte 12 Monate begrenzen
   let monthlyData = Object.values(buckets)
     .sort((a,b) => a.month.localeCompare(b.month))