Javascript date parsing bug - fails for dates in June (??)

Question

I have some javascript which parses an ISO-8601 date. For some reason, it is failing for dates in June. But dates in July and May work fine, which doesn\'t make sense to m

Answer 1

Looks like a bug?

C:\Documents and Settings\me>java org.mozilla.javascript.tools.shell.Main
Rhino 1.7 release 2 2009 03 22
js> date = new Date();
Fri Jul 31 2009 15:18:38 GMT-0400 (EDT)
js> date.setUTCMonth(5); date.toUTCString();
Wed, 01 Jul 2009 19:18:38 GMT
js> date.setUTCMonth(5); date.toUTCString();
Mon, 01 Jun 2009 19:18:38 GMT

EDIT: Nevermind I guess. Question already answered by somebody more knowledgable.