Posts within the last 7 days

Greets:

I’m trying to figure out a mthod of displaying the posts created within the last x amount of days. I gather that this doesn’t work:

$dt_start = mktime(0, 0, 0, date("n"), date("j"), date("Y"));
$dt_recent = $dt_start - 604800;

$query2  = "SELECT * FROM wp_posts WHERE $dt_recent <= strtotime('post_date_gmt') ORDER BY ID";

Suggestions?

Thanks,
-drmike