好吧，我创建了您的日程安排程序，而不是更易读的方式使用类

<?php

class Day
{
    private $free;
    private $workingHours;
    private $name;

    function __construct(string $name, bool $free, $workingHours = 0)
    {
        $this->name = $name;
        $this->free = $free;
        $this->workingHours = $workingHours;
    }

    public function setWorkingHours(int $workingHours)
    {
        $this->workingHours = $workingHours;
    }

    public function getWorkingHours(): int
    {
        return $this->workingHours;
    }

    public function isFree(): bool
    {
        return $this->free;
    }

    public function __toString()
    {
        return $this->name;
    }
}

class Scheduler
{
    const MONDAY = 'mon';
    const TUESDAY = 'tue';
    const WEDNESDAY = 'wed';
    const THURSDAY = 'thu';
    const FRIDAY = 'fri';
    const SATURDAY = 'sat';
    const SUNDAY = 'sun';

    public function createSchedule(\DateTime $startDate, \DateTime $endDate, int $totalHours, array $scheduledWeekDays): array
    {
        $schedule = [];
        $totalDays = 0;

        // Find all scheduled days
        while($startDate < $endDate) {
            $weekday = strtolower($startDate->format('D'));
            if ($this->isScheduledDay($weekday, $scheduledWeekDays)) {
                $schedule[] = new Day($weekday, false);
                $totalDays++;
            } else {
                $schedule[] = new Day($weekday, true);
            }
            $startDate->modify('+1days');
        }

        // Spread total hours evenly
        $hoursPerDay = floor($totalHours / $totalDays); // round it down
        $extraHours = $totalHours - ($hoursPerDay * $totalDays); // find the hours that were left by flooring

        $schedule = array_map(function(Day $day) use ($hoursPerDay) {
            if(!$day->isFree()) {
                $day->setWorkingHours($hoursPerDay);
            }

            return $day;
        }, $schedule);
        
        $lastDay = $schedule[count($schedule) - 1];
        $lastDay->setWorkingHours($lastDay->getWorkingHours() + $extraHours);

        return $schedule;
    }

    private function isScheduledDay(string $day, array $scheduledWeekDays)
    {
        return array_search($day, $scheduledWeekDays) !== false;
    }
}

$scheduler = new Scheduler();

$startDate = new \DateTime('tomorrow');
$endDate = (clone $startDate)->modify('+1week');

$schedule = $scheduler->createSchedule($startDate, $endDate, 16, [Scheduler::SATURDAY, Scheduler::SUNDAY]);

// 8 hours on saturday, and sunday
foreach($schedule as $day) {
    $text = 'Week day: ' . $day . '<br>';
    if($day->isFree()) {
        $text .= 'It\'s a free day enjoy ur time!';
    } else {
        $text .= 'Today you have to work ' . $day->getWorkingHours() . ' hours';
    }
    $text .= '<br><br>';

    echo $text;
}

例如，您可以扩展day类以表示这一天的确切日期。