public ActionResult BookingOverview(AdminBookingOverviewModel model)
        {
            if (ModelState.IsValid)
            {
                var date = new DateTime(model.Year.Value, model.Month.Value, 1);

                return(RedirectToAction(nameof(BookingOverview), new { date }));
            }

            return(RedirectToAction(nameof(BookingOverview)));
        }
        public ActionResult BookingOverview(DateTime?date)
        {
            var model = new AdminBookingOverviewModel();

            date = date ?? DateTime.Today;

            model.FirstDayOfMonth = DateTimeUtility.GetFirstDayOfMonth(date.Value);
            model.LastDayOfMonth  = DateTimeUtility.GetLastDayOfMonth(date.Value);
            model.Bookings        = Database.Instance.GetBookings(model.FirstDayOfMonth, model.LastDayOfMonth);

            return(View(model));
        }