Supertracker

[avf]

1. In sql replace
NOW()
by
date_add(now(), INTERVAL ' . TIME_ZONE_OFFSET . ' HOUR)
2. Replace
$thirty_mins_ago = date('Y-m-d H:i:s', (time() - (30*60)));
by
$thirty_mins_ago = date('Y-m-d H:i:s', (time()+TIME_ZONE_OFFSET*60*60 - (30*60)));

So should I rerun the sql with this new query as supertracker is already installed on my system ?

Also where do i define the time offset ?
Thanks