/*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