Make most arguments to Date constructor optional.

runtime/lib/date.dart

Index: runtime/lib/date.dart
diff --git a/runtime/lib/date.dart b/runtime/lib/date.dart
index dc69834bd167e91e47acffbcd361336fc2471927..bdfcca9c24f963645bd915e97125925681a4d6f2 100644
--- a/runtime/lib/date.dart
+++ b/runtime/lib/date.dart
@@ -18,12 +18,12 @@ class TimeZoneImplementation implements TimeZone {
 // JavaScript implementation of DateImplementation.
 class DateImplementation implements Date {
   factory DateImplementation(int years,
-                             int month,
-                             int day,
-                             int hours,
-                             int minutes,
-                             int seconds,
-                             int milliseconds) {
+                             [int month = 1,
+                              int day = 1,
+                              int hours = 0,
+                              int minutes = 0,
+                              int seconds = 0,
+                              int milliseconds = 0]) {
     return new DateImplementation.withTimeZone(
         years, month, day,
         hours, minutes, seconds, milliseconds,
@@ -112,8 +112,9 @@ class DateImplementation implements Date {
     return value == other.value && timeZone == other.timeZone;
   }
 
-  int compareTo(Date other) => value.compareTo(other.value);
-  int hashCode() => value;

[ngeoffray, 2012/05/15 12:17:35]

bad mergE?

[floitsch, 2012/05/15 12:34:22]

Done.

+  int compareTo(Date other) {
+    return value.compareTo(other.value);
+  }
 
   Date changeTimeZone(TimeZone targetTimeZone) {
     if (targetTimeZone === null) {
@@ -209,7 +210,7 @@ class DateImplementation implements Date {
     }
     String threeDigits(int n) {
       if (n >= 100) return "${n}";
-      if (n >= 10) return "0${n}";

[ngeoffray, 2012/05/15 12:17:35]

ditto?

[floitsch, 2012/05/15 12:34:22]

Done.

+      if (n > 10) return "0${n}";
       return "00${n}";
     }
     String twoDigits(int n) {