Document DateTime.parse accepted format.

tests/corelib/date_time_test.dart

 // Copyright (c) 2012, 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.
 
 import "package:expect/expect.dart";
 
 // Dart test program for DateTime.
 
 // Identical to _MAX_MILLISECONDS_SINCE_EPOCH in date_time.dart
 const int _MAX_MILLISECONDS = 8640000000000000;
@@ skipping 914 matching lines @@
       Expect.equals(source2, utcTime1.toIso8601String());
     }
   }
   test("2000-01-01", "12:00:00.000");
   test("-2000-01-01", "12:00:00.000");
   test("1970-01-01", "00:00:00.000");
   test("1969-12-31", "23:59:59.999");
   test("1969-09-09", "00:09:09.009");
 }
 
+void testIsoString() {
+  var d = new DateTime(9999, 1, 1, 23, 59, 59, 999);
+  Expect.equals("9999-01-01T23:59:59.999", d.toIso8601String());
+  d = new DateTime(-9999, 1, 1, 23, 59, 59, 999);
+  Expect.equals("-9999-01-01T23:59:59.999", d.toIso8601String());
+  d = new DateTime.utc(9999, 1, 1, 23, 59, 59, 999);
+  Expect.equals("9999-01-01T23:59:59.999Z", d.toIso8601String());
+  d = new DateTime.utc(-9999, 1, 1, 23, 59, 59, 999);
+  Expect.equals("-9999-01-01T23:59:59.999Z", d.toIso8601String());
+
+  d = new DateTime(10000, 1, 1, 23, 59, 59, 999);
+  Expect.equals("+010000-01-01T23:59:59.999", d.toIso8601String());
+  d = new DateTime(-10000, 1, 1, 23, 59, 59, 999);
+  Expect.equals("-010000-01-01T23:59:59.999", d.toIso8601String());
+  d = new DateTime.utc(10000, 1, 1, 23, 59, 59, 999);
+  Expect.equals("+010000-01-01T23:59:59.999Z", d.toIso8601String());
+  d = new DateTime.utc(-10000, 1, 1, 23, 59, 59, 999);
+  Expect.equals("-010000-01-01T23:59:59.999Z", d.toIso8601String());
+}
+
 void main() {
   testNow();
   testValue();
   testConstructors();
   testUTCGetters();
   testLocalGetters();
   testChangeTimeZone();
   testSubAdd();
   testUnderflowAndOverflow();
   testDateStrings();
   testEquivalentYears();
   testExtremes();
   testFarAwayDates();
   testWeekday();
   testToStrings();
+  testIsoString();
 }