{
    local $\ = "\n";
    print scalar localtime;
    {
        local %ENV;
        $ENV{TZ} = 'GMT';
        print scalar localtime;
    }
    print scalar localtime;
}

##</code><code>##

Wed May 29 23:29:08 2002
Wed May 29 21:29:08 2002
Wed May 29 23:29:08 2002