Help with getting data from two excel sheets and compare them

Hi, I'm doing an application to read excel sheets, and I need to know if what I'm doing is the best or if someone else comes up with another idea, tell me before I get into this.

I explain the process, first I take the excel file and I transform it into a csv file with the following method.

public static bool SaveAsCsv(string excelFilePath, string destinationCsvFilePath)
        {

            using (var stream = new FileStream(excelFilePath, FileMode.Open, FileAccess.Read, FileShare.ReadWrite))
            {
                IExcelDataReader reader = null;
                if (excelFilePath.EndsWith(".xls"))
                {
                    reader = ExcelReaderFactory.CreateBinaryReader(stream);
                }
                else if (excelFilePath.EndsWith(".xlsx"))
                {
                    reader = ExcelReaderFactory.CreateOpenXmlReader(stream);
                }

                if (reader == null)
                    return false;

                var ds = reader.AsDataSet(new ExcelDataSetConfiguration()
                {
                    ConfigureDataTable = (tableReader) => new ExcelDataTableConfiguration()
                    {
                        UseHeaderRow = false
                    }
                });

                var csvContent = string.Empty;
                int row_no = 0;
                while (row_no < ds.Tables[0].Rows.Count)
                {
                    var arr = new List<string>();
                    for (int i = 0; i < ds.Tables[0].Columns.Count; i++)
                    {
                        arr.Add(ds.Tables[0].Rows[row_no][i].ToString());
                    }
                    row_no++;
                    csvContent += string.Join(",", arr) + "\n";
                }
                StreamWriter csv = new StreamWriter(destinationCsvFilePath, false);
                csv.Write(csvContent);
                csv.Close();
                return true;
            }
        }

and I call it in the following way

  var excelFilePath = "Direccion del archivo";
  string output = Path.ChangeExtension(excelFilePath, ".csv");
  Form1.SaveAsCsv(excelFilePath, output);

Then the csv file I take it and I read it

public List parseCSV (string path)         {             List parsedData = new List ();

        using (StreamReader readFile = new StreamReader(path))
        {
            string line;
            string[] row;

            while ((line = readFile.ReadLine()) != null)
            {
                row = line.Split(',');
                parsedData.Add(row);
            }
        }
        return parsedData;
    }

And here I call the method

try
            {
                dt.Clear();
                List<string[]> testParse = parseCSV(@"Direccion del archivo");


                foreach (string column in testParse[0])
                {
                    dt.Columns.Add(column);
                }

               foreach (string[] row in testParse)
               {
                    if (row.Contains("Condiciones que no quiero")) { }
                    else if (row.Contains("Condiciones que no quiero")) { }
                    else if (row.Contains("Condiciones que no quiero")) { }
                    else if (row.Contains("Condiciones que no quiero")) { }
                    else { dt.Rows.Add(row); }
                }
            }
            catch(Exception ex)
            {
                MessageBox.Show("No existe ningún archivo CSV con ese nombre. " + ex.Message);
            }
            dataGridView1.DataSource = dt;


            foreach (DataRow row in dt.Rows)
            {
                foreach (DataColumn column in dt.Columns)
                {
                    //row[column] obtiene el valor de las columnas de la fila


                }
            }

And it works already I saw the data that I have what happens is that now I want to pass everything to a database to make queries there and my idea is to send all the records to the database with the following

  foreach (DataRow row in dt.Rows)
                {
                    foreach (DataColumn column in dt.Columns)
                    {
                        //row[column] obtiene el valor de las columnas de la fila


                    }
                }

but I do not know if it is correct or possible because apart from that what I have to compare from this document with the other are names and hours, but the time of one of the documents is in the following format 7:55 am or pm, while in the other document is from 3:40 pm or even 30:02 that would be 6:02 am and I want to know how I can convert this data to this format 6:02 am and then how to compare ... I do not know if explain me well any lack of information tell me, thanks in advance friends