BUG: Need to format message, not ValueError instance

zipline/lib/adjusted_array.py

@@ -82,7 +82,8 @@ def _normalize_array(data):
                 "not representable as datetime64[ns].\n"
                 "Min Date: %s\n"
                 "Max Date: %s\n"
-            ) % (data.min(), data.max())
+                % (data.min(), data.max())
+            )
     else:
         raise TypeError(
             "Don't know how to construct AdjustedArray "