Querying Relationships

Hey guys, I am developing a hotel reservation system. My models include user, hotel, room and reservation. A room belongs to a hotel, whereas a reservation belongs to a room. My room schema includes a reserved column that is true or false, depending on whether the room is reserved or not. In the reservations schema, i have a column known as departure date.

So here is my question, when a room is reserved, i want to display a statement reading unavailable till ____ (1 day after the departure date in the reservation table). How can i accomplish that? I have already created the relationships.

Room.php

<?php

namespace App;

use Illuminate\Database\Eloquent\Model;

class Room extends Model
{
    /**
     * The attributes that are mass assignable.
     *
     * @var array
     */
    protected $fillable = [
        'name', 'image', 'room_information', 'price', 'no_of_persons', 'reserved', 'hotel_id',
    ];

    /**
     * One to Many relationship with room
     *
     */
    public function hotel()
    {
        return $this->belongsTo('App\Hotel');
    }

    /**
     * Many to Many relationship with amenity
     *
     */
    public function amenities()
    {
        return $this->belongsToMany('App\Amenity');
    }

    /**
     * One to Many relationship with reservation
     *
     */
    public function reservations()
    {
        return $this->hasMany('App\Reservation');
    }

    /**
     *
     *
     */
    public function unreserved()
    {
        
    }


}

Reservation.php

<?php

namespace App;

use Illuminate\Database\Eloquent\Model;
use Illuminate\Support\Str;

class Reservation extends Model
{
    /**
     * The attributes that are mass assignable.
     *
     * @var array
     */
    protected $fillable = [
        'reservation_no', 'client_name', 'client_email', 'arrival_date', 'departure_date', 'number_of_people', 'user_id', 'room_id', 'length_of_stay', 'total_cost',
    ];

    /**
     *
     * Boot the model
     *
     */

    public static function boot()
    {
        parent::boot();

        static::creating(function ($reservation) {
            $reservation->reservation_no = strtoupper('br') . "-" . strtoupper(Str::random(10));
        });
    }

    /**
     * One to Many relationship with user
     *
     */
    public function user()
    {
        return $this->belongsTo('App\User');
    }

    /**
     * One to Many relationship with room
     *
     */
    public function room()
    {
        return $this->belongsTo('App\Room');
    }
}

PageController.php (I need help on what to pass to the $departure variable)

 public function getRoomDetail($name)
    {
        $room = Room::where('name', '=', $name)->first();

        if ($room->reserved == true) {
            $day_after_departure = strtotime('+1 day', $departure);
        }

        
        //$room_by_location = Room::where('location',$room->location)->orderBy('created_at', 'desc')->paginate(3);
        $room_by_persons = Room::where('no_of_persons', $room->no_of_persons)->orderBy('created_at', 'desc')->get();
        $room_by_hotel = Room::where('hotel_id', $room->hotel_id)->orderBy('created_at', 'desc')->get();
        $room_by_price = Room::where('price', $room->price)->orderBy('created_at', 'desc')->get();
        return view('frontend.pages.rooms.room-detail', compact('room', 'room_by_hotel', 'room_by_persons', 'room_by_price'));
    }