CLN: fix the tz_localization mess on construction

Author: jreback

pandas/core/ops.py

@@ -545,9 +545,9 @@ def _offset(lvalues, rvalues):
 
                 # with tz, convert to UTC
                 if self.is_datetime64tz_lhs:
-                    lvalues = lvalues.tz_localize(None)
+                    lvalues = lvalues.tz_convert('UTC').tz_localize(None)
                 if self.is_datetime64tz_rhs:
-                    rvalues = rvalues.tz_localize(None)
+                    rvalues = rvalues.tz_convert('UTC').tz_localize(None)
 
                 lvalues = lvalues.view(np.int64)
                 rvalues = rvalues.view(np.int64)

pandas/io/packers.py

@@ -597,15 +597,9 @@ def decode(obj):
 
         dtype = dtype_for(obj[u'dtype'])
         pd_dtype = pandas_dtype(dtype)
-        tz = getattr(pd_dtype, 'tz', None)
 
-        arr = unconvert(obj[u'data'], dtype, obj[u'compress'])
-
-        if tz:
-            result = klass(arr, index=index, dtype=pd_dtype.base, name=name)
-            result = result.dt.tz_localize('UTC').dt.tz_convert(tz)
-        else:
-            result = klass(arr, index=index, dtype=pd_dtype, name=name)
+        result = klass(unconvert(obj[u'data'], dtype, obj[u'compress']),
+                       index=index, name=name, dtype=pd_dtype)
         return result
 
     elif typ == u'block_manager':

pandas/types/cast.py

@@ -825,7 +825,7 @@ def _possibly_cast_to_datetime(value, dtype, errors='raise'):
                             # localize
                             value = to_datetime(
                                 value,
-                                errors=errors).tz_localize(dtype.tz)
+                                errors=errors).tz_localize('UTC').tz_convert(dtype.tz)
                         elif is_timedelta64:
                             value = to_timedelta(value, errors=errors)._values
                     except (AttributeError, ValueError, TypeError):