Update app.py

app.py

@@ -196,11 +196,13 @@ def preprocess_data(df, le_user=None, le_item=None, scaler=None):
         df["user_id_idx"] = le_user.fit_transform(df["Customer_ID"].values)
     if le_item is not None:
         df["item_id_idx"] = le_item.fit_transform(df["Item_ID"].values)
+    df["Timestamp"] = pd.to_datetime(df["Timestamp"], unit='s')
+
     if scaler is not None:
-        df["Timestamp"] = pd.to_datetime(df["Timestamp"])
-        df["Timestamp_numeric"] = df["Timestamp"].astype("int64") // 10**9  # seconds since epoch
+        # Option 1: scale based on numeric timestamp
+        df["Timestamp_numeric"] = df["Timestamp"].astype(np.int64) // 10**9
         df["Date"] = scaler.fit_transform(df[["Timestamp_numeric"]])
-
+    
     return df