--- a/interfaces.py	Tue Jun 23 08:44:42 2009 +0200
+++ b/interfaces.py	Tue Jun 23 10:53:57 2009 +0200
@@ -197,6 +197,14 @@
     """interface for items that do have a begin date 'start' and an end date 'stop'
     """
 
+    @property
+    def start(self):
+        """return start date"""
+
+    @property
+    def stop(self):
+        """return stop state"""
+
 class ICalendarViews(Interface):
     """calendar views interface"""
     def matching_dates(self, begin, end):