Make date parser handle all ES5 Date Time Strings correctly.

src/date.js

 // Copyright 2006-2008 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 963 matching lines @@
 
 function PadInt(n, digits) {
   if (digits == 1) return n;
   return n < MathPow(10, digits - 1) ? '0' + PadInt(n, digits - 1) : n;
 }
 
 
 function DateToISOString() {
   var t = DATE_VALUE(this);
   if (NUMBER_IS_NAN(t)) return kInvalidDate;
-  return this.getUTCFullYear() + 
+  var year = this.getUTCFullYear();
+  var year_string;
+  if (year >= 0 && year <= 9999) {
+    year_string = PadInt(year, 4);
+  } else {
+    if (year < 0) {
+      year_string = "-" + PadInt(-year, 6);
+    } else {
+      year_string = "+" + PadInt(year, 6);
+    }
+  }
+  return year_string +
       '-' + PadInt(this.getUTCMonth() + 1, 2) +
-      '-' + PadInt(this.getUTCDate(), 2) + 
+      '-' + PadInt(this.getUTCDate(), 2) +
       'T' + PadInt(this.getUTCHours(), 2) +
-      ':' + PadInt(this.getUTCMinutes(), 2) + 
+      ':' + PadInt(this.getUTCMinutes(), 2) +
       ':' + PadInt(this.getUTCSeconds(), 2) +
       '.' + PadInt(this.getUTCMilliseconds(), 3) +
       'Z';
 }
 
 
 function DateToJSON(key) {
   var o = ToObject(this);
   var tv = DefaultNumber(o);
-  if (IS_NUMBER(tv) && !NUMBER_IS_FINITE(tv)) { 
-    return null; 
+  if (IS_NUMBER(tv) && !NUMBER_IS_FINITE(tv)) {
+    return null;
   }
   return o.toISOString();
 }
 
 
 function ResetDateCache() {
 
   // Reset the local_time_offset:
   local_time_offset = %DateLocalTimeOffset();
 
@@ skipping 84 matching lines @@
     "toGMTString", DateToGMTString,
     "toUTCString", DateToUTCString,
     "getYear", DateGetYear,
     "setYear", DateSetYear,
     "toISOString", DateToISOString,
     "toJSON", DateToJSON
   ));
 }
 
 SetupDate();