using System;

using Newtonsoft.Json;

using Newtonsoft.Json.Converters;

​

public class Program

{

    public static void Main()

    {

        var obj = new PreOrder

        {

            time = new DateTime(2013, 1, 20, 0, 0, 0, DateTimeKind.Utc),

        };

​

        var json = JsonConvert.SerializeObject(obj, Formatting.Indented);

        Console.WriteLine(json);

    }

}

​

class MyDateConverter : IsoDateTimeConverter

{

    public override void WriteJson(JsonWriter writer, object value, JsonSerializer serializer)

    {

        writer.WriteStartObject();

        writer.WritePropertyName("$date");

        base.WriteJson(writer, value, serializer);

        writer.WriteEndObject();

    }

}

​

public class PreOrder

{

    [JsonConverter(typeof(MyDateConverter))]

    public DateTime time { get; set; }

}

​