bug#641: format-time-string %Z does not work, starting with Emacs 22.2

[martin rudalics]

> emacs -Q
> M-: (format-time-string "%Z) ==> ""
> M-: (format-time-string "%z) ==> "-0700"
>
> The %Z string is incorrect. In my case, it should be (as it is in
> Emacs 20 and Emacs 22.1): "Pacific Daylight Time".
>
> This same bug appears in Emacs 23.  This is a regression from Emacs
> 22.1.

See

2007-06-07  Jason Rumney  <jasonr@gnu.org>

        * s/ms-w32.h: Don't define HAVE_TZNAME.

        * editfns.c (Fcurrent_time_zone): Remove hack for Japanese Windows.

and the preceding discussion starting with

http://lists.gnu.org/archive/html/emacs-devel/2007-06/msg00334.html

martin