private static void TimerTick(object sender, EventArgs e) { foreach (var rentedCar in rentedCars) { if (rentedCar.Item2 < DateTime.Now) { var conn = new DBConnectionString(); var car = conn.Автомобиль.FirstOrDefault(x => x.id == rentedCar.Item1); if (car != null) { car.Доступность = true; } rentedCars.Remove(rentedCar); conn.SaveChangesAsync(); } } }