gitpython-developers
diff --git a/‎git/objects/util.py
+1-1 b/‎git/objects/util.py
+1-1
@@ -249,7 +249,7 @@ def parse_date(string_date: Union[str, datetime]) -> Tuple[int, int]:
             raise ValueError("no format matched")
         # END handle format
     except Exception as e:
-        raise ValueError(f"Unsupported date format or type: {string_date}" % string_date) from e
+        raise ValueError(f"Unsupported date format or type: {string_date}, type={type(string_date)}") from e
     # END handle exceptions