Update pyfolio/mcp_output/mcp_plugin/mcp_service.py

pyfolio/mcp_output/mcp_plugin/mcp_service.py

@@ -79,9 +79,16 @@ def _save_plot_as_base64(plt, plot_name):
 def _convert_to_series(data: List[float], name: str = "returns") -> pd.Series:
     """Convert list to pandas Series with date index."""
     if isinstance(data, list):
+        # Create a business day date range to avoid NaT issues
+        try:
+            date_index = pd.date_range("2020-01-01", periods=len(data), freq="B")
+        except Exception:
+            # Fallback to daily frequency if business day fails
+            date_index = pd.date_range("2020-01-01", periods=len(data), freq="D")
+        
         return pd.Series(
             data, 
-            index=pd.date_range("2020-01-01", periods=len(data), freq="D"),
+            index=date_index,
             name=name
         )
     return data