thinkphp5 返回数组提示variable type error： array

 function timeArr(){
       $time = array();
       for($i=1;$i<=7;$i++){
            $d=  date(‘d‘,Time::daysAgo($i)   );
            $qian = strtotime(date(‘Y-m-d‘,Time::daysAgo($i)  ).‘00:00:00‘);
            $hou = strtotime(date(‘Y-m-d‘,Time::daysAgo($i)   ).‘23:59:59‘);
            $time[$d] = [ $qian,$hou];
       }
       ksort($time);
       return $time;
    }