Changes in anticipation of stricter str vs. bytes enforcement.
diff --git a/Lib/test/test_datetime.py b/Lib/test/test_datetime.py
index b26c92e..dce9fc3 100644
--- a/Lib/test/test_datetime.py
+++ b/Lib/test/test_datetime.py
@@ -1085,7 +1085,7 @@
             # This shouldn't blow up because of the month byte alone.  If
             # the implementation changes to do more-careful checking, it may
             # blow up because other fields are insane.
-            self.theclass(bytes(base[:2] + chr(ord_byte) + base[3:]))
+            self.theclass(bytes(base[:2] + chr(ord_byte) + base[3:], "ascii"))
 
 #############################################################################
 # datetime tests