using System;

using Newtonsoft.Json;

using Newtonsoft.Json.Converters;

​

public class Program

{

    public static void Main(string[] args)

    {

        var dynamicObject = new

        {

            utcDate = DateTime.UtcNow, //This one has Kind = DateTimeKind.Utc

            localDate = DateTime.Now //This one has Kind = DateTimeKind.Local

        }

​

        ;

        var isoDateTimeConverter = new IsoDateTimeConverter();

        isoDateTimeConverter.DateTimeFormat = "yyyy'-'MM'-'dd'T'HH':'mm':'ssK";

        var serializerSettings = new JsonSerializerSettings();

        serializerSettings.Converters.Add(isoDateTimeConverter);

        var s = new System.Text.StringBuilder();

        using (var w = new System.IO.StringWriter(s))

        using (var writer = new JsonTextWriter(w)

                   {Formatting = Formatting.Indented})

        {

            var serializer = JsonSerializer.Create(serializerSettings);

            serializer.Serialize(writer, dynamicObject);

            writer.Flush();

        }

​

        Console.WriteLine(s.ToString());

    }

}