Parsing dates with format that's just month or day will fail on certain days

pkg/intl/lib/date_format_helpers.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.
 
 /**
  * A class for holding onto the data for a date so that it can be built
  * up incrementally.
  */
 class _DateBuilder {
   int year = 0,
@@ skipping 11 matching lines @@
   void setYear(x) { year = x; }
   void setMonth(x) { month = x; }
   void setDay(x) { day = x; }
   void setHour(x) { hour = x; }
   void setMinute(x) { minute = x; }
   void setSecond(x) { second = x; }
   void setFractionalSecond(x) { fractionalSecond = x; }
 
   /**
    * Return a date built using our values. If no date portion is set,
-   * use today's date, as otherwise the constructor will fail.
+   * use the "Epoch" (January 1, 1970), since the constructor will fail if

[Anton Muhin, 2012/08/30 17:44:03]

nit: I think "since the constructor..." can be omitted as it's an implementation
detail.

[Alan Knight, 2012/08/30 17:50:40]

Done.

+   * given zero values for those fields.
    */
   Date asDate() {
     if (year == 0 || month == 0 || day == 0) {
-      var today = new Date.now();
-      if (year == 0) year = today.year;
-      if (month == 0) month = today.month;
-      if (day == 0) day = today.day;
+      if (year == 0) year = 1970;

[Anton Muhin, 2012/08/30 17:44:03]

maybe just make those default values for fields?

[Alan Knight, 2012/08/30 17:50:40]

Yes, that's much nicer. Done.

+      if (month == 0) month = 1;
+      if (day == 0) day = 1;
     }
 
     // TODO(alanknight): Validate the date, especially for things which
     // can crash the VM, e.g. large month values.
     return new Date(
         year,
         month,
         day,
         pm ? hour + 12 : hour,
         minute,
@@ skipping 76 matching lines @@
    * can see and then return the corresponding integer. Advance the stream.
    */
   var digitMatcher = const RegExp(@'\d+');
   int nextInteger() {
     var string = digitMatcher.stringMatch(rest());
     if (string == null || string.isEmpty()) return null;
     read(string.length);
     return parseInt(string);
   }
 }