Date Range comparison in Lambda Expression (Entity Framework)

 public IEnumerable<CRM_Customer> GetCustomersByMultipleFilter(DateTime sEnlistedDate, DateTime eEnlistedDate, string Branch, int Category,string Gender, int City, int Location, int AgeFrom, int AgeTo, DateTime BirthdayDate,DateTime MarriageDayDate, string SingleCustomer)
        {
            DateTime minDate = Convert.ToDateTime(DateTime.MinValue.ToShortDateString());

            IEnumerable<CRM_Customer> CustomerList = (from a in DbContext.CRM_Customer

                                where (a.SubscriptionDate >= sEnlistedDate && a.SubscriptionDate <= eEnlistedDate)

                                && ((DateTime.Now.Year - ((a.DOB.Value.Year))) >= AgeFrom && (DateTime.Now.Year - ((a.DOB.Value.Year))) <= AgeTo)

                                && ((((a.BranchId) == Branch) && (Branch != "-1")) || (Branch == "-1"))

                                && ((((a.CategoryId) == Category) && (Category != -1)) || (Category == -1))

                                && ((((a.CityId) == City) && (City != -1)) || (City == -1))

                                && ((((a.LocationId) == Location) && (Location != -1)) || (Location == -1))

                                && ((((a.Gender) == Gender) && (Gender != "-1")) || (Gender == "-1"))

                                && (((DbFunctions.TruncateTime(a.DOB) == DbFunctions.TruncateTime(BirthdayDate)) && (BirthdayDate != minDate)) || (BirthdayDate == minDate))

                                && (((DbFunctions.TruncateTime(a.AnniversaryDate) == DbFunctions.TruncateTime(MarriageDayDate)) && (MarriageDayDate != minDate)) || (MarriageDayDate == minDate))

                                && (((a.FirstName + a.MiddleName + a.LastName).ToUpper().Contains(SingleCustomer.ToUpper()) && (SingleCustomer != "-1")) || (SingleCustomer == "-1"))

                                select a).ToList();

            return CustomerList;

        }