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Description of problem:

Some dates are not constructed/displayed properly.

Version-Release number of selected component (if applicable):

firefox-10.0.7-1.el6_3

How reproducible:
always

Steps to Reproduce:
1. Create a web page containing the following javascript code

date1 = new Date(2012, 9, d);
alert(date1.getDate());

for various values of d.

2. Browse to the web page using Firefox.
  
Actual results:
d   alert message
26  26
27  27
28  27
29  30
30  31

Expected results:
alert = d for all values of d

Additional info:
none

Timezone is Europe/London, so daylight savings ends at 03:00 Oct 28 2012.

This request was not resolved in time for the current release.
Red Hat invites you to ask your support representative to
propose this request, if still desired, for consideration in
the next release of Red Hat Enterprise Linux.

Seems to be fixed in new versions (at least Firefox-23.0.1). The fix will hit RHEL sooner or later with new firefox versions. We're not going to ship a special fix for RHEL, so closing as WONTFIX for now.