[bira]

Parker try this (I've not tested it yet):

in forumdisplay.php find (around line 311):

if ($daysprune!=1000) {
  $checkdate = time() - ($daysprune*86400);
  $datecut='AND lastpost >= '.$checkdate;
}

Replace it with:

if ($daysprune!=1000) {
	if ($daysprune=='-2') {
		$datecut='AND lastpost >= '.$bbuserinfo[lastvisit];	
	} else {
		$checkdate = time() - ($daysprune*86400);
  		$datecut='AND lastpost >= '.$checkdate;
  	}
}

Add <option value='-2'>Since your last visit</option> to the daysprune select.

That's it.