--- a/server/sqlutils.py	Mon Sep 14 11:15:47 2015 +0200
+++ b/server/sqlutils.py	Mon Oct 12 10:53:35 2015 +0200
@@ -21,11 +21,11 @@
 __docformat__ = "restructuredtext en"
 
 import sys
-import os
 import re
 import subprocess
 from os.path import abspath
 from logging import getLogger
+from datetime import time, datetime
 
 from six import string_types
 from six.moves import filter
@@ -34,6 +34,7 @@
 from logilab.common.shellutils import ProgressBar, DummyProgressBar
 from logilab.common.deprecation import deprecated
 from logilab.common.logging_ext import set_log_methods
+from logilab.common.date import utctime, utcdatetime
 from logilab.database.sqlgen import SQLGenerator
 
 from cubicweb import Binary, ConfigurationError
@@ -376,8 +377,17 @@
                 # convert cubicweb binary into db binary
                 if isinstance(val, Binary):
                     val = self._binary(val.getvalue())
+                # convert timestamp to utc.
+                # expect SET TiME ZONE to UTC at connection opening time.
+                # This shouldn't change anything for datetime without TZ.
+                elif isinstance(val, datetime) and val.tzinfo is not None:
+                    val = utcdatetime(val)
+                elif isinstance(val, time) and val.tzinfo is not None:
+                    val = utctime(val)
                 newargs[key] = val
             # should not collide
+            assert not (frozenset(newargs) & frozenset(query_args)), \
+                'unexpected collision: %s' % (frozenset(newargs) & frozenset(query_args))
             newargs.update(query_args)
             return newargs
         return query_args