diff --git a/addons/base_calendar/base_calendar.py b/addons/base_calendar/base_calendar.py
index 5bc12c69671..0f5848c286e 100644
--- a/addons/base_calendar/base_calendar.py
+++ b/addons/base_calendar/base_calendar.py
@@ -19,7 +19,7 @@
 #
 ##############################################################################
 
-from datetime import datetime, timedelta
+from datetime import datetime, timedelta, date
 from dateutil import parser
 from dateutil import rrule
 from osv import fields, osv