DateTime conversion of datetime objects with non-pytz tzinfo.

        Timezones() returns a copy of the timezone list (allows tests to run).

doc/CHANGES.txt

@@ -204,6 +204,9 @@ Zope Changes
 
     Bugs Fixed
 
+      - DateTime conversion of datetime objects with non-pytz tzinfo. 
+        Timezones() returns a copy of the timezone list (allows tests to run).
+
       - LP #253362: better dealing with malformed HTTP_ACCEPT_CHARSET headers
 
       - Launchpad #246748: added 'immediate' option to sendXXX() methods

lib/python/DateTime/DateTime.py

@@ -599,7 +599,8 @@ class DateTime:
                     tz = None
                 else:
                     self._timezone_naive = False
-                    tz = arg.tzinfo.zone
+                    # if we have a pytz tzinfo, use the `zone` attribute as a key
+                    tz = getattr(arg.tzinfo, 'zone', numerictz)
                 ms = sc - math.floor(sc)
                 x = _calcDependentSecond2(yr,mo,dy,hr,mn,sc)
 
@@ -1850,5 +1851,5 @@ class strftimeFormatter:
 # Module methods
 def Timezones():
     """Return the list of recognized timezone names"""
-    return PytzCache._zlst
+    return list(PytzCache._zlst)
 

lib/python/DateTime/tests/testDateTime.py

@@ -19,7 +19,7 @@ import unittest
 
 from DateTime.DateTime import _findLocalTimeZoneName, _cache
 from DateTime import DateTime
-from datetime import datetime
+from datetime import datetime, tzinfo, timedelta
 import pytz
 import legacy
 
@@ -34,6 +34,24 @@ else:
 DATADIR = os.path.dirname(os.path.abspath(f))
 del f
 
+ZERO = timedelta(0)
+
+class FixedOffset(tzinfo):
+    """Fixed offset in minutes east from UTC."""
+
+    def __init__(self, offset, name):
+        self.__offset = timedelta(minutes = offset)
+        self.__name = name
+
+    def utcoffset(self, dt):
+        return self.__offset
+
+    def tzname(self, dt):
+        return self.__name
+
+    def dst(self, dt):
+        return ZERO
+
 
 class DateTimeTests(unittest.TestCase):
 
@@ -561,8 +579,17 @@ class DateTimeTests(unittest.TestCase):
         real_failures = list(set(failures).difference(set(expected_failures)))
             
         self.failIf(real_failures, '\n'.join(real_failures))
-            
-            
+    
+    def testBasicTZ(self):
+        """psycopg2 supplies it's own tzinfo instances, with no `zone` attribute
+        """
+        tz = FixedOffset(60, 'GMT+1')
+        dt1 = datetime(2008, 8, 5, 12, 0, tzinfo=tz)
+        DT = DateTime(dt1)
+        dt2 = DT.asdatetime()
+        offset1 = dt1.tzinfo.utcoffset(dt1)
+        offset2 = dt2.tzinfo.utcoffset(dt2)
+        self.assertEqual(offset1, offset2)
 
 
 def test_suite():