private List <List <string> > FilterNewRecords(List <List <string> > tableData, ScrapPage page, ColumnMapping dateCol) { var dateColIndex = page.ColumnMappings.IndexOf(dateCol); var latestDateInFileStr = _csvReader.GetLastDate(page.FilePath, dateColIndex); _logger.Info("latestDateInFileStr = " + latestDateInFileStr); if (string.IsNullOrWhiteSpace(latestDateInFileStr)) { return(tableData); //all records are new } var latestDateInFile = DateTime.ParseExact(latestDateInFileStr, dateCol.OutputDateFormat, CultureInfo.InvariantCulture); var filtered = tableData.Where(x => DateTime.ParseExact(x[dateColIndex], dateCol.OutputDateFormat, CultureInfo.InvariantCulture) > latestDateInFile); return(filtered.ToList()); }