php 获取指定日期是的星期几，根据本周周一时间 获取本周时间对应的7天星期

<?php
header("content-type:text/html;charset=utf-8");
    date_default_timezone_set('PRC');
    function getWeek($unixTime=''){
        $unixTime=is_numeric($unixTime)?$unixTime:time();
        $weekarray=array('日','一','二','三','四','五','六','七');
        return "星期".$weekarray[date('w',$unixTime)];
    }
    $var=getWeek();
    switch($var){
        case '星期天':
            $var=time();
            $var2=$var-(84600*6);
            echo "这个星期天是".date("Y-m-d",$var2)."号";
        break;
        case '星期一':
            $var=time();
            $var2=$var;
            echo "这个星期一是".date("Y-m-d",$var2)."号";
        break;
        case '星期二':
            $var=time();
            $var2=$var-84600;
            echo "这个星期二是".date("Y-m-d",$var2)."号";
        break;
        case '星期三':
            $var=time();
            $var2=$var-(84600*2);
            echo "这个星期三是".date("Y-m-d",$var2)."号";
        break;
        case '星期四':
            $var=time();
            $var2=$var-(84600*3);
            echo "这个星期四是".date("Y-m-d",$var2)."号";
        break;
        case '星期五':
            $var=time();
            $var2=$var-(84600*4);
            echo "这个星期五是".date("Y-m-d",$var2)."号";
        break;
        case '星期六':
            $var=time();
            $var2=$var-(84600*5);
            echo "这个星期六是".date("Y-m-d",$var2)."号";
        break;
    }
echo "<br/><br/><br/><br/><br/>";
$yue=date("Y-m");
$day1=date("d",$var2);
$day2=$day1+1;
$day3=$day1+2;
$day4=$day1+3;
$day5=$day1+4;
$day6=$day1+5;
$day7=$day1+6;
$date1=$yue."-".$day1;
$date2=$yue."-".$day2;
$date3=$yue."-".$day3;
$date4=$yue."-".$day4;
$date5=$yue."-".$day5;
$date6=$yue."-".$day6;
$date7=$yue."-".$day7;
$weekarray=array("日","一","二","三","四","五","六");
$week1=$weekarray[date("w",strtotime("$date1"))];
$week2=$weekarray[date("w",strtotime("$date2"))];
$week3=$weekarray[date("w",strtotime("$date3"))];
$week4=$weekarray[date("w",strtotime("$date4"))];
$week5=$weekarray[date("w",strtotime("$date5"))];
$week6=$weekarray[date("w",strtotime("$date6"))];
$week7=$weekarray[date("w",strtotime("$date7"))];
echo "
周第一天是： $date1 星期 $week1 <br/>
往后一天是： $date2 星期 $week2 <br/>
往后一天是： $date3 星期 $week3 <br/>
往后一天是： $date4 星期 $week4 <br/>
往后一天是： $date5 星期 $week5 <br/>
往后一天是： $date6 星期 $week6 <br/>
往后一天是： $date7 星期 $week7 <br/>
";
?>