I have done solution from my end

            for (DateTime? i = Fdate; i <= tdate; i = i.Value.AddDays(1))
            {
                List<DateTime?> dates = items.Select(x => x.Date).ToList();
                if (dates.Contains(i))
                {
                    var employeeItem = items.Where(x => x.Date .Date== i.Date).FirstOrDefault();
                    ItemList.Add(new
                    {
                        ItemId = employeeItem.ItemId,
                        ItemName = employeeItem.ItemName,
                        EId = employeeItem.EId,
                        EName = employeeItem.EName,
                        Date = i.Value.ToString("dd/MM/yyyy")
                    });
                }
            }