diff --git a/Doc/includes/tzinfo-examples.py b/Doc/includes/tzinfo-examples.py
index 2de95d4..5132429 100644
--- a/Doc/includes/tzinfo-examples.py
+++ b/Doc/includes/tzinfo-examples.py
@@ -71,7 +71,7 @@
     def _isdst(self, dt):
         tt = (dt.year, dt.month, dt.day,
               dt.hour, dt.minute, dt.second,
-              dt.weekday(), 0, -1)
+              dt.weekday(), 0, 0)
         stamp = _time.mktime(tt)
         tt = _time.localtime(stamp)
         return tt.tm_isdst > 0