$one_day = new DateInterval('P1D');
$six_days = new DateInterval('P6D');

$date = new DateTime('11/05/2010');
$date->sub($one_day);
$end_date=$date;
if($date->format("j")<7)  { $date->sub(new DateInterval('P1M')); }
$date=$date->format("n/1/Y");
$to=$end_date->format("n/j/Y");
$end_date->sub($six_days);
$from=$end_date->format("n/j/Y");
$data=array();

$exit=false;
while(1) {
        echo "\nFrom: {$from}\nTo: {$to}\n";
        if($exit) { break; }
        $tmp_date=$end_date;
        $tmp_date->sub($one_day);
        $to=$tmp_date->format("n/j/Y");
        $end_date->sub($six_days);
        $from=$end_date->format("n/j/Y");
        if(strtotime($from)<=strtotime($date))  {
                 $from=$date;
                 $exit=true;
        }
}