<?php

class WorkTime

{

    // 定义工作日 [1, 2, 3, 4, 5, 6, 0]

    public $week_workingday = [1, 2, 3, 4, 5];

    // 定义上下班时间

    public $on_duty_time = '9:00:00';

    public $off_duty_time = '18:00:00';

    //每天工作时长

    public $oneday_hours = null;

    public function __construct()

    {

        if (empty($this->oneday_hours)) {

            $this->oneday_hours = $this->off_duty_time - $this->on_duty_time;

        }

    }

    public function get_working_hours(int $start_time, int $over_time)

    {

        // 如果工作日列表为空 返回0

        $workingdays = $this->workingdays($start_time, $over_time);

        if (empty($workingdays)) {

            return 0;

        }

        // 如果开始时间不是工作日,将开始时间调整为第一个工作日的上班时间

        // 如果截止时间不是工作日,将开始时间调整为最后一个工作日的下班时间

        if (!in_array(date('Y/m/d', $start_time), $workingdays)) {

            $start_time = strtotime($workingdays[0] . ' ' . $this->on_duty_time);

        }

        if (!in_array(date('Y/m/d', $over_time), $workingdays)) {

            $over_time = strtotime(end($workingdays) . ' ' . $this->off_duty_time);

        }

        // 如果开始时间与截止时间是同一天,直接计算

        // 反之分别计算开始时间与截止时间

        if (date('Y/m/d', $start_time) == date('Y/m/d', $over_time)) {

            $sec = $over_time - $start_time;

            if ($sec > 3600 * $this->oneday_hours) {

                $sec = 3600 * $this->oneday_hours;

            }

            // 昨天到了计算秒数

        } else {

            // 计算开始日工作时间

            $start_day_sec = strtotime($workingdays[0] . ' ' . $this->off_duty_time) - $start_time;

            if ($start_day_sec > 3600 * $this->oneday_hours) {

                $start_day_sec = 3600 * $this->oneday_hours;

            }

            // 计算截止日工作时间

            $over_day_sec = $over_time - strtotime(end($workingdays) . ' ' . $this->on_duty_time);

            if ($over_day_sec > 3600 * $this->oneday_hours) {

                $over_day_sec = 3600 * $this->oneday_hours;

            }

            $all_day_sec = ((count($workingdays) - 2) * $this->oneday_hours) * 3600;

            $sec         = $start_day_sec + $over_day_sec + $all_day_sec;

        }

        return $sec / 3600;

    }

    # 计算工作日(包含开始与截止日期)

    protected function workingdays($start_time, $over_time)

    {

        $start_time = strtotime('-1 day', $start_time);

        $over_time  = strtotime('-1 day', $over_time);

        $new_workingdays = $this->new_workingdays();

        $new_holidays    = $this->new_holidays();

        $workingdays     = [];

        while ($start_time < $over_time) {

            $start_time     = strtotime('+1 day', $start_time);

            $is_holidays    = in_array(date('w', $start_time), $this->week_workingday) && !in_array(date('Y/m/d', $start_time), $new_holidays);

            $is_workingdays = in_array(date('Y/m/d', $start_time), $new_workingdays);

            if ($is_holidays || $is_workingdays) {

                $workingdays[] = date('Y/m/d', $start_time);

            }

        }

        return $workingdays;

    }

    # 新增工作日

    protected function new_workingdays()

    {

        $days = [

            '2020/05/09',

        ];

        return $days;

    }

    # 新增休息日

    protected function new_holidays()

    {

        $days = [

            '2020/05/01',

            '2020/05/04',

            '2020/05/05',

        ];

        return $days;

    }

}

$start_time = strtotime('2020-05-06 10:00:00');

$over_time  = strtotime('2020-05-11 18:00:00');

$work          = new WorkTime();

$working_hours = $work->get_working_hours($start_time, $over_time);

var_dump($working_hours);