Re : How can do change default locale? (UTC time)
The HTML code in tiki-admin-include-general.tpl was commented before 1.7.0 release on revision 1.7.2.8. I emailed Jeremy about this changed and mentioned this information request. Let's hope he's not dead since he didn't log on tw.o since august.
If no answer maybe someone can figure out what was done checking the changes :
http://cvsmonitor.tikiwiki.org/cvsmonitor.pl?cmd=viewBrowseAuthor&author=jjongsma&module=Tikiwiki.Tikiwiki