The time shown in the forum is the server time, the only way to change it to a different time zone is to get the server admin to physically change the time on the web server, which will also effect everyone else on the same server so I doubt they will do it.
However, each of your members can change the time offset in there profile to there local time zone, but the forum default will remain that of what the server is set to.
Changing the LCID number as shown above is only useful if you are getting a CDATE error, otherwise leave it how it is otherwise the active topics page will fail to work correctly. Also changing the LCID will only change the format of the dates and time, not the time off set.