MDP-395 _to_dt now actually uses the default_tz

Author: Artjoms Iskovs

arctic/tickstore/tickstore.py

@@ -504,8 +504,7 @@ def _to_dt(self, date, default_tz=None):
         elif date.tzinfo is None:
             if default_tz is None:
                 raise ValueError("Must specify a TimeZone on incoming data")
-            # Treat naive datetimes as London
-            return date.replace(tzinfo=mktz())
+            return date.replace(tzinfo=default_tz)
         return date
 
     def _str_dtype(self, dtype):