/*创建日期类型记录表格*/

 CREATE TABLE `tb_workday` (

 `did` int(11) NOT NULL AUTO_INCREMENT,

 `exact_date` varchar(32) NOT NULL COMMENT '具体日期：格式date("Ymd");(20170205)',

 `date_year` varchar(32) NOT NULL COMMENT '具体日期：格式date("Y");(2017)',

 `date_type` tinyint(2) NOT NULL COMMENT '日期类型：0、工作日；1、特殊工作日；2、法定节假日',

 PRIMARY KEY (`did`)

 ) ENGINE=InnoDB AUTO_INCREMENT=829 DEFAULT CHARSET=utf8 COMMENT='各年工作日&法定节假日数据'

 <?php

 class work_days

 {

   /**

    * 获取星期

    * @param $date

    * @return mixed

    */

   function get_week($date)

   {

     //强制转换日期格式

     $date_str = date('Y-m-d', strtotime($date));

     //封装成数组

     $arr = explode("-", $date_str);

     //参数赋值

     //年

     $year = $arr[0];

     //月，输出2位整型，不够2位右对齐

     $month = sprintf('%02d', $arr[1]);

     //日，输出2位整型，不够2位右对齐

     $day = sprintf('%02d', $arr[2]);

     //时分秒默认赋值为0；

     $hour = $minute = $second = 0;

     //转换成时间戳

     $strap = mktime($hour, $minute, $second, $month, $day, $year);

     //获取数字型星期几

     $number_wk = date("w", $strap);

     //获取数字对应的星期

     return $number_wk;

     //自定义星期数组

     //$weekArr = array("星期日", "星期一", "星期二", "星期三", "星期四", "星期五", "星期六");

     //获取数字对应的星期

     //return $weekArr[$number_wk];

   }

   /**

    * 获取指定日期段内每一天的日期

    * @param  string $startdate 开始日期

    * @param  string $enddate   结束日期

    * @return array

    */

   function getDateFromRange($startdate, $enddate)

   {

     $stimestamp = strtotime($startdate);

     $etimestamp = strtotime($enddate);

     // 计算日期段内有多少天

     $days = ($etimestamp - $stimestamp) / 86400 + 1;

     // 保存每天日期

     $_list_date = array();

     for ($i = 0; $i < $days; $i++) {

       $_list_date[] = date('Y-m-d', $stimestamp + (86400 * $i));

     }

     return $_list_date;

   }

   function curl_post($url, $data = null)

   {

     $curl = curl_init();

     curl_setopt($curl, CURLOPT_URL, $url);

     curl_setopt($curl, CURLOPT_SSL_VERIFYPEER, FALSE);

     curl_setopt($curl, CURLOPT_SSL_VERIFYHOST, FALSE);

     if (!empty($data)) {

       curl_setopt($curl, CURLOPT_POST, 1);

       curl_setopt($curl, CURLOPT_POSTFIELDS, $data);

     }

     curl_setopt($curl, CURLOPT_RETURNTRANSFER, 1);

     $output = curl_exec($curl);

     curl_close($curl);

     return $output;

   }

   /**

    * 更新数据库指定年份日期数据

    * @param $year

    * @return int

    */

   function updateDate($year)

   {

     $startDate = date('Y-m-d', strtotime($year . '-01-01'));

     $endDate = date('Y-m-d', strtotime('+1 year', strtotime($startDate)) - 86400);

     $_list_date = self::getDateFromRange($startDate, $endDate);

     $url = 'http://api.goseek.cn/Tools/holiday';//自行查找的免费API

     $m = M('tb_workday');

     $count = 0;

     foreach ($_list_date as $k => $_date) {

       $_ret = 0;

       $_date = date('Ymd', strtotime($_date));

       $_post_data = array('date' => $_date);

       $_ret_curl = curl_post($url, $_post_data);

       $_ret_curl = json_decode($_ret_curl, true);

       //工作日

       if ($_ret_curl['data'] == 0) {

         $dateData['exact_date'] = $_date;

         $dateData['date_year'] = $year;

         $dateData['date_type'] = 0;

         $_ret = $m->add($dateData) ? 1 : 0;

         unset($dateData);

         //工作日 判断是否为周末

         if (in_array(self::get_week($_date), array(0, 1))) {

           //特殊工作日

           $dateData['exact_date'] = $_date;

           $dateData['date_year'] = $year;

           $dateData['date_type'] = 1;

           $_ret = $m->add($dateData) ? 1 : 0;

           unset($dateData);

         }

       }

       //法定节假日

       if ($_ret_curl['data'] == 2) {

         $dateData['exact_date'] = $_date;

         $dateData['date_year'] = $year;

         $dateData['date_type'] = 2;

         $_ret = $m->add($dateData) ? 1 : 0;

         unset($dateData);

       }

       //休息日(周末) 暂不处理

       /*if ($_ret_curl['data'] == 1) {

       }*/

       $_ret && $count++;

       unset($_date, $_post_data, $_ret_curl, $_ret);

     }

     return $count;

   }

   /**

    * 获取当年所有工作日 (从数据库获取，数据库无数据则先更新数据)

    * @param string $year 当年年份

    * @return array

    */

   private function getWorkDays($year)

   {

     $m = M('tb_workday');

     $map['date_year'] = $year;

     $map['date_type'] = 0;

     $DateArray = $m->field('exact_date')->where($map)->select();

     if (!empty($DateArray)) {

       $DateArray = array_column($DateArray, 'exact_date');

       return $DateArray;

     } else {

       //更新数据库工作日数据

       $ret = self::updateDate($year);

       if ($ret > 0) {

         return self::getWorkDays($year);

       } else {

         return false;

       }

     }

   }

   /**

    * 获取开始日期后第N个工作日具体日期

    * @param $startdate string 计算开始日期  需包含年月日信息

    * @param $days      int 间隔天数

    * @return mixed 成功返回 对应日期，失败返回false

    */

   public function getNextWorkDate($startdate, $days)

   {

     $year = date('Y', strtotime($startdate));

     $startdate = date('Y-m-d', strtotime($startdate));

     $workDays = $this->getWorkDays($year);

     $search_key = array_search(date('Ymd', strtotime($startdate)), $workDays);

     if ($search_key === false) {//查询日期为非工作

       //获取查询日期前最近工作日

       $m = M('tb_workday');

       $map['date_year'] = $year;

       $map['date_type'] = 0;

       $map['DATE_FORMAT(`exact_date`,\'%Y-%m-%d\')'] = array('LT', $startdate);

       $_search_date = $m->where($map)->order('`exact_date` DESC')->getField('exact_date');

       $search_key = array_search($_search_date, $workDays);

       unset($m, $map, $_search_date);

     }

     $t_key = $search_key + $days;

     if ($t_key <= count($workDays) - 1) {

       return date('Y-m-d', strtotime($workDays[$t_key]));

     } else {

       //查询日期已跨年

       $n_days = $days - (count($workDays) - 1 - $search_key);

       $next_year = $year + 1;

       return $this->getNextWorkDate($next_year . '-01-01', $n_days - 1);

     }

   }

 }

 $startdate = '2018-09-28';

 $days = 5;

 $class = new work_days();

 $_date_workday = $class->getNextWorkDate($startdate, $days);

 echo $_date_workday;//2018-10-10