Rename Date to DateTime.

tests/corelib/core_runtime_types_test.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.
 
 /**
  * A test of simple runtime behavior on numbers, strings and lists with
  * a focus on both correct behavior and runtime errors.
  *
  * This file is written to use minimal type declarations to match a
  * typical dynamic language coding style.
@@ skipping 235 matching lines @@
     assertEquals(d.keys.length, 2);
     assertEquals(d.values.length, 2);
 
     d['g'] = null;
     assertEquals(d.containsKey('g'), true);
     assertEquals(d['g'], null);
   }
 
   static testDateMethods() {
     var msec = 115201000;
-    var d = new Date.fromMillisecondsSinceEpoch(msec, isUtc: true);
+    var d = new DateTime.fromMillisecondsSinceEpoch(msec, isUtc: true);
     assertEquals(d.second, 1);
     assertEquals(d.year, 1970);
 
-    d = new Date.now();
+    d = new DateTime.now();
     assertEquals(d.year >= 2011, true);
   }
 
   static testLiterals() {
     true.toString();
     1.0.toString();
     .5.toString();
     1.toString();
     if (false) {
       // Depends on http://b/4198808.
       null.toString();
     }
     '${null}'.toString();
     '${true}'.toString();
     '${false}'.toString();
     ''.toString();
     ''.endsWith('');
   }
 }
 
 main() {
   CoreRuntimeTypesTest.testMain();
 }