how to convert iso datetime to date in c#?

Question

I m failing to convert an ISO DateTime format value to date value only. I tried Parse, ParseExact and TryParseExact and all failed and keep giving me the same value output (1984-04-26T00:00:00).

I have referred to many references and other SO questions but none helped

I am using a DTO and this is the property,

public DateTime Dob { get; set; }

I am running a for loop to join data from my LINQ queries and I am trying to do my conversion as follows,

for (int i = 0; i < PatientInfo.Count; i++)
{
    PatientInfo[i].Dob =
    DateTime.Parse(String.Format("{0:MM/dd/yyyy}", PatientInfo[i].Dob.ToString()));
    PatientInfo[i].PartnerData = PartnerInfo.Where(a => a.FileId == PartnerInfo[i].FileId).ToList();
}

What am I missing here?

the following is the API controller code,

[HttpGet("{id}")]
public async Task<IActionResult> GetPatReg([FromRoute] long id)
{
    if (!ModelState.IsValid)
    {
        return BadRequest(ModelState);
    }

    var PatientInfo = await _context.PatReg
        .Where(a => a.FileId == id)
        .Select(b => new PatRegDto
        {
            Action = "Get",
            FileId = b.FileId,
            FName = b.FName,
            MName = b.MName,
            LName = b.LName,
            Dob = b.Dob
        }).ToListAsync();
    var PartnerInfo = await _context.PatPar
        .Where(s => s.FileId == id)
        .Select(m => new PatParDto
        {
            RecId = m.RecId,
            FileId = m.FileId,
            ParFileId = m.ParFileId,
            SDate = m.SDate,
            EDate = m.EDate,
        }).ToListAsync();

    for (int i = 0; i < PartnerInfo.Count; i++)

    {
        PartnerInfo[i].FullName = _context.PatReg.Where(a => a.FileId == PartnerInfo[i].ParFileId)
                               .Select(t => new { t.fullname })
                               .Single().fullname;
        PartnerInfo[i].dob = _context.PatReg.Where(a => a.FileId == PartnerInfo[i].ParFileId)
                               .Select(t => new { t.Dob })
                               .Single().Dob;

        PartnerInfo[i].Action = "Get";
    }

    for (int i = 0; i < PatientInfo.Count; i++)

    {
        PatientInfo[i].Dob =
        DateTime.Parse(String.Format("{0:MM/dd/yyyy}", PatientInfo[i].Dob.ToString()));

        PatientInfo[i].PartnerData = PartnerInfo.Where(a => a.FileId == PartnerInfo[i].FileId).ToList();
    }

    if (PatientInfo == null)
    {
        return NotFound();
    }

    var DataRes = new
    {
        sdata = PatientInfo
    };

    return Ok(DataRes);
}

Update My DTOs are

    public class PatRegDto

    {
        public string Action { get; set; }
        private Int64 _FileId;
        public Int64 FileId
        {
            get
            {
                return this._FileId;
            }
            set
            {
                this._FileId = value;
            }
        }
        public string FName { get; set; }
        public string MName { get; set; }
        public string LName { get; set; }
        public string fullname
        {
            get { return FName + " " + MName + " " + LName; }
        }
        public DateTime Dob { get; set; }
        public List<PatParDto> PartnerData { get; set; }
    }
    public class PatParDto

    {
        public string Action { get; set; }
        public long RecId { get; set; }
        public long FileId { get; set; }
        public long ParFileId { get; set; }
        public DateTime SDate { get; set; }
        public DateTime? EDate { get; set; }
        public DateTime dob { get; set; }
        public string FullName { get; set; }
    }

Answer 1

Please do not use PatientInfo[i].Dob.ToString()) because it will be serialized to string using your current culture settings. Depends on your OS language settings you will have different string. Beside that DateTime contains Date property that returns date ;)

Answer 2

So is this the only solution? I add a public string DobFormat { get; set; } to the PatRegDto DTO and then,

for (int i = 0; i < PatientInfo.Count; i++)

            {
                PatientInfo[i].DobFormat = PatientInfo[i].Dob.ToString("MM/dd/yyyy");
                PatientInfo[i].PartnerData = PartnerInfo.Where(a => a.FileId == PartnerInfo[i].FileId).ToList();

            }

Answer 3

Another Answer per all the valuable comments above,

public class PatRegDto

{
    public string Action { get; set; }
    private Int64 _FileId;
    public Int64 FileId
    {
        get
        {
            return this._FileId;
        }
        set
        {
            this._FileId = value;
        }
    }
    public string FName { get; set; }
    public string MName { get; set; }
    public string LName { get; set; }
    public string fullname
    {
        get { return FName + " " + MName + " " + LName; }
    }
    public string Dob { get; set; }
    public List<PatParDto> PartnerData { get; set; }
}

and in the controller

var PatientInfo = await _context.PatReg
        .Where(a => a.FileId == id)
        .Select(b => new PatRegDto
        {
            Action = "Get",
            FileId = b.FileId,
            FName = b.FName,
            MName = b.MName,
            LName = b.LName,
            Dob = (b.Dob).ToString("dd/M/yyyy"),
        }).ToListAsync();