diff --git a/src/App.tsx b/src/App.tsx
index d635a2f..1a17d0f 100644
--- a/src/App.tsx
+++ b/src/App.tsx
@@ -168,10 +168,22 @@ export default function App() {
             
             // Only preserve Supabase values if there's a PENDING or EDITED edit for this article
             if (synced && (synced.status === 'pending' || synced.status === 'edited' || synced.status === 'synced')) {
-              // Keep the manually edited values from Supabase
+              // DETECT COLUMN SHIFT: If the saved data uses the old structure (where index 12 was a numeric date),
+              // we need to shift all indices from 12 onwards by +1 to match today's Excel structure.
+              const oldData = synced.data;
+              const valAt12 = oldData[12];
+              // Launch Date was index 12 yesterday and it's always a numeric serial.
+              // PM Classification is index 12 today and it's a string or empty.
+              const needsShift = typeof valAt12 === 'number' || (typeof valAt12 === 'string' && /^[0-9.]+$/.test(valAt12));
+              
               editableColumns.forEach(idx => {
-                if (synced.data[idx] !== undefined && synced.data[idx] !== null) {
-                  finalRow[idx] = synced.data[idx];
+                let mergeIdx = idx;
+                if (needsShift && idx >= 12) {
+                  mergeIdx = idx - 1;
+                }
+                
+                if (oldData[mergeIdx] !== undefined && oldData[mergeIdx] !== null) {
+                  finalRow[idx] = oldData[mergeIdx];
                 }
               });
               setRowStatuses(prev => ({ ...prev, [articleNo]: 'synced' }));