Time zone problem in cygwin

[Ken Brown]

I just built emacs 23 under cygwin from the cvs source of two days ago, 
and the time zone is off by 4 hours; display-time shows 1:30pm when the 
local time is 9:30am.  This happens under both cygwin 1.5 and the (still 
experimental) cygwin 1.7.  The problem does not occur in my build of 
emacs 22.3.  I see in the archives that this problem was reported before:

   http://lists.gnu.org/archive/html/emacs-devel/2008-11/msg00532.html

Eli Zaretskii replied and asked for the value of (format-time-string 
"%Y-%m-%d %T %z").   The OP never responded, but the answer for me is 
the following:  emacs 23 incorrectly reports 2009-02-05 13:35:36 -0100, 
whereas emacs 22.3 correctly gives 2009-02-05 09:36:13 -0500 a few 
seconds later.  One further detail:  emacs 23 gives the right time if I 
set TZ=America/New_York prior to starting emacs; but my understanding is 
that it's not supposed to be necessary to set TZ.

Ken