PHPで日付の月の週を取得する方法

<?php
$time = strtotime(&#39;2019-01-01&#39;);
$wk_day = date(&#39;w&#39;, strtotime(date(&#39;Y-m-1 00:00:00&#39;, $time))) ? : 7; //今天周几
$day = date(&#39;d&#39;, $time) - (8 - $wk_day); //今天几号
echo $day <= 0 ? 1 : ceil($day / 7) + 1; //计算是第几个星期
 
print_r(week_of_month(strtotime(&#39;2019-01-1&#39;)));
 
function week_of_month($time, $offset = 1){
        $week = get_week_block($time);
        $wk_day = date(&#39;w&#39;, strtotime(date(&#39;Y-m-1 00:00:00&#39;, $time))) ? : 7; //今天周几
        $day = date(&#39;d&#39;, $time) - (8 - $wk_day); //今天几号
        $weekof = $day <= 0 ? 1 : ceil($day / 7) + 1; //计算是第几个星期
        if($offset){
            $week[0] = date(&#39;Y-m-d&#39;, max(strtotime(date(&#39;Y-m-1 00:00:00&#39;, $time)), $week[0]));
            $week[1] = date(&#39;Y-m-d&#39;, min(strtotime(date(&#39;Y-m-&#39;.date(&#39;t&#39;, $time).&#39; 23:59:59&#39;, $time)), $week[1]));
        }else{
            $week[0] = date(&#39;Y-m-d&#39;, $week[0]);
            $week[1] = date(&#39;Y-m-d&#39;, $week[1]);
        }
        return [&#39;week&#39; => $week, &#39;weekof&#39; => $weekof];
}
 
function get_week_block($sdefaultDate = false, $first = 1){
//当前日期    
//$first =1 表示每周星期一为开始日期 0表示每周日为开始日期  
if(!$sdefaultDate)$sdefaultDate = time();
if(is_numeric($sdefaultDate))$sdefaultDate = date(&#39;Y-m-d&#39;, $sdefaultDate);
//获取当前周的第几天 周日是 0 周一到周六是 1 - 6  
$w=date(&#39;w&#39;, strtotime($sdefaultDate));  
//获取本周开始日期，如果$w是0，则表示周日，减去 6 天  
$week_start=date(&#39;Y-m-d&#39;,strtotime("$sdefaultDate -".($w ? $w - $first : 6).&#39; days&#39;));  
//本周结束日期  
$week_end=date(&#39;Y-m-d&#39;,strtotime("$week_start +6 days"));
return array(strtotime($week_start.&#39; 00:00:00&#39;), strtotime($week_end.&#39; 23:59:59&#39;));
}