Reply To: Query to search available apartments

No, WP_Query is only for posts and reservations aren’t.
But you can make a database query for each resource that checks if the resource is free now.
The query goes to the table reservations and should count the reservations where “NOW() BETWEEN arrival AND departure”. If the database and php time aren’t the same you’ll have to use date(‘Y-m-d H:i:s’); in a variable instead of NOW(). The relate the amount with the resource count.
Everything else depends on your set up and requirement. Write where you have problems.