vB 3.5 Timezoneoffset difference?

[Boofo]

Can anyone tell me what has changed in this code from 3.0 to 3.5 where the DST code no longer works in it?

PHP Code:

  $servertime = ($timeoffset - ($timediff));  //Server is on GMT time
 if ($bbuserinfo['dstonoff'])
 {
  // DST is on, add an hour
  $servertime++;
  if (substr($servertime, 0, 1) != '-')
  {
   // recorrect so that it has + sign, if necessary
   $servertime = '+' . $servertime;
  }
 }