BUG: Index created from FixedOffset tz without a name loses tz awaren…

…ess #2604

pandas/tseries/tests/test_timezones.py

@@ -60,6 +60,7 @@ def dst(self, dt):
         return timedelta(0)
 
 fixed_off = FixedOffset(-420, '-07:00')
+fixed_off_no_name = FixedOffset(-330, None)
 
 class TestTimeZoneSupport(unittest.TestCase):
     _multiprocess_can_split_ = True
@@ -190,6 +191,16 @@ def test_create_with_fixed_tz(self):
         rng3 = date_range('3/11/2012 05:00:00+07:00', '6/11/2012 05:00:00+07:00')
         self.assert_((rng.values == rng3.values).all())
 
+    def test_create_with_fixedoffset_noname(self):
+        off = fixed_off_no_name
+        start = datetime(2012, 3, 11, 5, 0, 0, tzinfo=off)
+        end = datetime(2012, 6, 11, 5, 0, 0, tzinfo=off)
+        rng = date_range(start=start, end=end)
+        self.assertEqual(off, rng.tz)
+
+        idx = Index([start, end])
+        self.assertEqual(off, idx.tz)
+
     def test_date_range_localize(self):
         rng = date_range('3/11/2012 03:00', periods=15, freq='H', tz='US/Eastern')
         rng2 = DatetimeIndex(['3/11/2012 03:00', '3/11/2012 04:00'],

pandas/tslib.pyx

@@ -700,7 +700,10 @@ cdef inline object _get_zone(object tz):
         return 'UTC'
     else:
         try:
-            return tz.zone
+            zone = tz.zone
+            if zone is None:
+                return tz
+            return zone
         except AttributeError:
             return tz