Adding a patient then searching for by DOB in FHIR

FhirPatient.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using Hl7.Fhir.Rest;
using Hl7.Fhir.Model;


namespace PatientLogger
{
    class Program
    {
        static void Main(string[] args)
        {
            string endpoint = "http://test.fhir.org/r3";
            var server = new FhirClient(endpoint);

            // Adding a patient
            // Anthony Edward "Tony" Stark

           var p = new Patient();
            var n = new HumanName();
            var _givens = new List<string>();
            _givens.Add("Anthony");
            _givens.Add("Edward");
            n.Family = "Stark";
            n.Text = "Anthony Edward \"Tony\" Stark";
            n.Given = _givens;
            p.Name.Add(n);

            p.BirthDate = "1963-03";
            p.Gender = AdministrativeGender.Male;
            
            var i = new Attachment();
            i.Url = "https://pre00.deviantart.net/63c6/th/pre/i/2016/098/4/f/tony_stark_01_by_merrogers-d9y8ni1.png";
            p.Photo.Add(i);

            p.Active = true;

            p.Id = "iamironman";

            server.Create<Patient>(p);


            //Searching for a patient
            var x = new SearchParams();
            x.Add("birthDate", "1963");

            var found = server.Search<Patient>(x);

            foreach (var item in found.Entry)
            {
                var pat = (Patient)item.Resource;

                Console.WriteLine(pat.Name.FirstOrDefault().Family);
                


            }

            Console.WriteLine(); 

            Console.WriteLine("Done");
            Console.ReadKey();
        }
    }
}