求个PHP列出周日期代码,该怎么解决

//打印周五

$week = getdate();

//echo $week['wday'];

if($week['wday']==5)

//echo $week['year'].'年'.$week['mon'].'月'.$week['mday'].'日';

//echo $week[year].'年'.$week[mon].'月'.$week[mday].'日';



for($i=1;$i<=20;$i++)

{

$j=$i*-7;

$k=$j+7;

echo date("Y年m月d日",strtotime($j." days"));

echo "->".date("Y年m月d日",strtotime($k." days"));

echo "
";

}

?>

$s='2013-05-31';

$current=date("Y-m-d");

while($current>=$s){

    $ar[]=$current;

	$current=date("Y-m-d",strtotime("$current -7 day"));

}

	for($i=0;$i
	   echo $ar[$i+1].'->'.$ar[$i]."\n";

	}

for($i=0,$t=-7; $i<20; $i++,$t-=7) {

  echo date('Y-m-d -> ', strtotime("$t day"));

  echo date('Y-m-d', strtotime(($t+7)."day")) . '
';

}