fix: Convert timestamp after cleaning

app.py

@@ -84,10 +84,13 @@ def clean_data(df):
 def master(file):
     # read file
     data = pd.read_csv(file.name)
-    data['timestamp'] = pd.to_datetime(data['timestamp'])
 
     # clean data
     data = clean_data(data)
+
+    # Convert timestamp to datetime after cleaning
+    data['timestamp'] = pd.to_datetime(data['timestamp'])
+
     data.set_index("timestamp", inplace=True)
 
     df_test_value = normalize_data(data)