中邪了吗？怎么都是星期四

<?$weekarray=array("日","一","二","三","四","五","六");$windex = date("N",'2016-03-18 17:30:01');$ww = $weekarray[$windex];echo $ww;$windex = date("N",'2016-03-19 17:30:01');$ww = $weekarray[$windex];echo $ww;$windex = date("N",'2016-03-20 17:30:01');$ww = $weekarray[$windex];echo $ww;$weekarray=array("日","一","二","三","四","五","六");echo "星期".$weekarray[date("w","2011-11-12")];

?>
我这里的输出是：
四四四星期四

回复讨论(解决方案)

PHP Version 5.5.9

$windex = date("N", '2016-03-18 17:30:01');
PHP 5.5.9 的 date 能接受这样的参数吗？
不需要 strtotime 转换？
'1970-01-01  就是星期四，您可以去查一下万年历

date("N") 得到的范围是 1~7，星期日为 7
date("w") 得到的范围是 0~6，星期日为 0