new Date.now() should be in local timezone.

runtime/lib/date.dart

 // Copyright (c) 2011, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 // Dart core library.
 
 // VM implementation of DateImplementation.
 class DateImplementation implements Date {
   static final int _SECONDS_YEAR_2035 = 2051222400;
 
   DateImplementation(int years,
                      [int month = 1,
                       int day = 1,
                       int hours = 0,
                       int minutes = 0,
                       int seconds = 0,
                       int milliseconds = 0,
                       bool isUtc = false])
       : _isUtc = isUtc,
         value = _brokenDownDateToMillisecondsSinceEpoch(
             years, month, day, hours, minutes, seconds, milliseconds, isUtc) {
     if (value === null) throw new IllegalArgumentException();
   }
 
   DateImplementation.now()
-      : _isUtc = true,
+      : _isUtc = false,
         value = _getCurrentMs() {
   }
 
   factory DateImplementation.fromString(String formattedString) {
     // Read in (a subset of) ISO 8601.
     // Examples:
     //    - "2012-02-27 13:27:00"
     //    - "2012-02-27 13:27:00.423z"
     //    - "20120227 13:27:00"
     //    - "20120227T132700"
@@ skipping 366 matching lines @@
 
   static int _getHours(int secondsSinceEpoch, bool isUtc)
       native "DateNatives_getHours";
 
   static int _getMinutes(int secondsSinceEpoch, bool isUtc)
       native "DateNatives_getMinutes";
 
   static int _getSeconds(int secondsSinceEpoch, bool isUtc)
       native "DateNatives_getSeconds";
 }