How to retrive date in correct format from Database using C# in ASP.Net

Check with the below code.

public ArrayList GetPos()
{
    ArrayList list = null;
    if (HttpContext.Current.Session["ArrayPos"] == null)
    {
        list = new ArrayList();
        SqlConnection con = new SqlConnection(ConfigurationManager.ConnectionStrings[1].ConnectionString);
        SqlCommand cmd = new SqlCommand();
        cmd.CommandType = System.Data.CommandType.Text;
        cmd.CommandText = "select firstname,name,CONVERT(VARCHAR(20),birthday,102) birthday from Info";
        cmd.Connection = con;
        con.Open();
        SqlDataReader rdr = cmd.ExecuteReader();
        while (rdr.Read())
        {
            list.Add(string.Join(";", rdr["firstname"], rdr["name"], rdr["birthday"]));
        }
        HttpContext.Current.Session["ArrayPos"] = list;
    }
    else
    {
        list = HttpContext.Current.Session["ArrayPos"] as ArrayList;
    }
    return list;
}

protected void Button1_Click(object sender, EventArgs e)
{
    ArrayList dt = GetPos();
    int index = 0;
    string[] pos = dt[index].ToString().Split(';');
    FirstName.Text = pos[0].ToString();
    Name.Text = pos[1].ToString();
    string[] bDate = pos[2].Split('.');
    Birthday.Text = bDate[2] + "." + bDate[1] + "." + bDate[0];
}