pocketmine\level\Level::checkSleep PHP Method

    public function checkSleep()
    {
        if (count($this->players) === 0) {
            return;
        }
        $resetTime = true;
        foreach ($this->getPlayers() as $p) {
            if (!$p->isSleeping()) {
                $resetTime = false;
                break;
            }
        }
        if ($resetTime) {
            $time = $this->getTime() % Level::TIME_FULL;
            if ($time >= Level::TIME_NIGHT and $time < Level::TIME_SUNRISE) {
                $this->setTime($this->getTime() + Level::TIME_FULL - $time);
                foreach ($this->getPlayers() as $p) {
                    $p->stopSleep();
                }
            }
        }
    }