to get the server offset, first try to find the location of the server of the webhost, say if its located in los angeles, LA's time offset from GMT is -8, multiply by 60*60, you get 28000 and from there you can base the time offset, just do trial and error, i forgot how the hell did i get it

you may remove some text in tracker.php, unfortunately it will affect all of your user, so better do it in css