using System;

using System.Collections.Generic;

using System.IO;

using System.Dynamic;

using System.Globalization;

using CsvHelper;

using CsvHelper.TypeConversion;

​

public class Program

{

    public static void Main()

    {

        var records = new List<dynamic>();

        dynamic record = new ExpandoObject();

        record.Timestamp = DateTime.UtcNow;

        records.Add(record);

        using (var writer = new StringWriter())

        using (var csv = new CsvWriter(writer, CultureInfo.InvariantCulture))

        {

            var options = new TypeConverterOptions { Formats = new [] {"s"} };

            csv.Configuration.TypeConverterOptionsCache.AddOptions<DateTime>(options);

            csv.WriteRecords(records);

            writer.ToString().Dump();

        }

    }

}