--- a/utils.py	Wed Aug 25 18:29:55 2010 +0200
+++ b/utils.py	Wed Aug 25 18:55:58 2010 +0200
@@ -369,7 +369,7 @@
     json_dumps = None
 
 else:
-
+    from logilab.common.date import ustrftime
     class CubicWebJsonEncoder(json.JSONEncoder):
         """define a json encoder to be able to encode yams std types"""
 
@@ -379,9 +379,9 @@
                 d['eid'] = obj.eid
                 return d
             if isinstance(obj, datetime.datetime):
-                return obj.strftime('%Y/%m/%d %H:%M:%S')
+                return ustrftime(obj, '%Y/%m/%d %H:%M:%S')
             elif isinstance(obj, datetime.date):
-                return obj.strftime('%Y/%m/%d')
+                return ustrftime(obj, '%Y/%m/%d')
             elif isinstance(obj, datetime.time):
                 return obj.strftime('%H:%M:%S')
             elif isinstance(obj, datetime.timedelta):