public void SetNewOrdersRange(int m = 0)
        {
            DateTime dt = DateTime.Now.AddMonths(m);

            StartDt = GetMonth(dt);
            EndDt   = GetMonth(dt).AddMonths(1).AddDays(-1);
            UpdateOrders(GetOrdersOfMonth(dt));
            Calc.CalkDiscounts(orders.ToList());

            DataCatalogsSingleton.Instance.ChangeOrderDateRange(StartDt, EndDt.AddDays(1));
        }
        public List <OrderFlight> GetOrderFlightsOfMonth(DateTime date)
        {
            DateTime           fDt    = new DateTime(date.Year, date.Month, 1);
            DateTime           eDt    = new DateTime(date.AddMonths(1).Year, date.AddMonths(1).Month, 1);
            List <OrderFlight> flList = new List <OrderFlight>();

            if (!dOrders.TryGetValue(fDt, out flList))
            {
                flList = DBProvider.GetOrders(StartDt, EndDt.AddDays(-1), out List <OrderFlight> sVOOrders);
                dOrders.Add(StartDt, flList);
            }
            return(flList);
        }