请问如何统计本周是从几号到几号?

Question

<?php
$week = date("w"); // 今天是星期几，0=星期天
echo date("周一是：Y年m月d日",strtotime("-".($week-1)." day"))."<br>";
echo date("周日是：Y年m月d日",strtotime(7-$week." day"))."<br>";
echo date("下周一是：Y年m月d日",strtotime("week",strtotime("-".($week-1)." day")))."<br>";
echo date("下周日是：Y年m月d日",strtotime("week",strtotime(7-$week." day")))."<br>";
echo date("上周一是：Y年m月d日",strtotime("-1 week",strtotime("-".($week-1)." day")))."<br>";
echo date("上周日是：Y年m月d日",strtotime("-1 week",strtotime(7-$week." day")))."<br>";?>
依次类推