max vibes

app.py

@@ -326,14 +326,14 @@ def generate_hindcast(sensor_internal: str, days: int) -> str | None:
     df["sensor_whitehall_street"]    = sensor_flags["sensor_whitehall_street"]
 
     # Convert date to ordinal (model expects numeric date)
-    df["date"] = df["date"].apply(lambda d: d.toordinal())
+    df["date_ordinal"] = df["date"].apply(lambda d: d.toordinal())
 
-    # Build X with exact required order
-    X_df = df[feature_order]
+    # Build X with correct order using the ordinal date
+    X_df = df.assign(date=df["date_ordinal"])[feature_order]
 
     # Predict hindcast
     df["predicted_pm25"] = model.predict(X_df)
-    df_hind = df
+    df_hind = df  # df still has real dates!
 
     tmp_path = tempfile.NamedTemporaryFile(suffix=".png", delete=False).name
     sensor_label = SENSOR_LABELS[sensor_internal]