PHP计算指定时间段内周末天数(星期日天数)、双休天数、总工作日天数

  /**
     * | Author: Saron.Mo <momosweb@qq.com>
     * | @param char|int $start_date 一个有效的日期格式，例如：20091016，2009-10-16
     * | @param char|int $end_date 同上
     * | @param int $weekend_days 一周休息天数
     * | @return array
     * | array[total_days]  给定日期之间的总天数
     * | array[total_relax] 给定日期之间的周末天数
     */
    function get_weekend_days($start_date, $end_date, $weekend_days = 2)
    {

        $data = array();
        if (strtotime($start_date) > strtotime($end_date)) list($start_date, $end_date) = array($end_date, $start_date);

        $start_reduce = $end_add = 0;
        $start_N      = date('N', strtotime($start_date));
        $start_reduce = ($start_N == 7) ? 1 : 0;

        $end_N = date('N', strtotime($end_date));

        // 进行单、双休判断，默认按单休计算
        $weekend_days = intval($weekend_days);
        switch ($weekend_days) {
            case 2:
                in_array($end_N, array(6, 7)) && $end_add = ($end_N == 7) ? 2 : 1;
                break;
            case 1:
            default:
                $end_add = ($end_N == 7) ? 1 : 0;
                break;
        }

        $days = round(abs(strtotime($end_date) - strtotime($start_date)) / 86400) + 1;
        $data['total_days'] = $days;
        $data['total_relax'] = floor(($days + $start_N - 1 - $end_N) / 7) * $weekend_days - $start_reduce + $end_add;

        return $data;
    }

$day = get_weekend_days('2020-07-09', '2020-07-16', 2);
print_r($day);
exit;