php获得当月的节假日函数（包含周末，年度节假日）

根据下单日期，获得最早可预约时间（可预约时间可以根据需求调整）

//测试
    public function jisuan_riqi(){
        $create_time = '2020-04-09';//下单时间
        $jiejia_date = ['2019-12-31'=>2,'2020-01-23'=>8,'2020-04-03'=>4,'2020-04-30'=>6,'2020-06-24'=>4,'2020-09-31'=>9];//国家法定假
        $work_date = 3;//下单时间距预约的时间(相当于三个工作日才能约)
        $yuyue_time = $this->yuyue_date($create_time,$jiejia_date,$work_date);
        var_dump($yuyue_time);die;
    }
 
    //获得当前月的周末集合
    public function dangyue($create_time){
        $strtotime = strtotime($create_time);
        $month = date('m',$strtotime);
        $year = date('Y',$strtotime);
        $days = date("t", mktime(0,0,0, $month, 1, $year));//当年当月的天数
        $startweek = date("w", mktime(0,0,0, $month, 1, $year));
        $nums = $startweek;
        $datea = [];
        for($i=0;$i<$days;$i++){
            $str = ($i+1 > 9)?$i+1:'0'.($i+1);
            if($nums == 6){
                $datea[] = "$year-$month-".$str;
            }elseif($nums == 7){
                $datea[] = "$year-$month-".$str;
                $nums = 0;
            }
            $nums++;
        }
        return $datea;
    }
 
 
    /**
    *计算可预约时间函数
    *@param  $create_time 创建时间
    *@param  $jiejia_date 节假日集合
    *@param  $work_date 下单时间距预约的时间(相当于三个工作日才能约)
    **/
    public function yuyue_date($create_time,$jiejia_date,$work_date,$nums=2){
        $time = $create_time;
        for($s=0;$s<$nums;$s++){
            $time = date('Y-m-d',strtotime("{$time}+$s month"));
            $array = $this->dangyue($time);
            foreach($array as $k=>$v){
                $datea[] = $v;
            }
        }
        //筛选国家法定假
        foreach($jiejia_date as $key=>$val){
            for($v=0;$v<$val;$v++){
                $dateb[] =  date('Y-m-d',strtotime("{$key}+1+$v day"));
            }
        }
        $date = array_merge($datea,$dateb);
        $n = 0;       
        do {
            $create_time = date('Y-m-d',strtotime("{$create_time}+1 day"));
            if(!in_array($create_time,$date)){
                $n++;
            }
        } while ($work_date != $n);
        return $create_time;
    }