Here's what I did for my users online today part of forumhome and it seems to work great for each user's time offset.
PHP Code:
$timestamp = vbmktime(0, 0, 0, vbdate('m', TIMENOW, false, false), vbdate('d', TIMENOW, false, false), vbdate('Y', TIMENOW, false, false));
Then set up your query something like this:
PHP Code:
<?
$result = mysql_query("select title,body from news WHERE dateline >= $timestamp order by dateline desc");
?>
The $timestamp will get each user's time according to their offset.