How to update my local time zone in forum posts?

just wondering how i can change the forum’s posting time display to match my current local time, each time i post and then review it, i see that it was done 4 hours from now in the future hehe. (and possibly switch to 12hr format as i am in the US and this is the format i am accustomed to)
i have yet to find a profile option or setting to adjust this, i thought setting location would do it, but it doesnt seem to.