How to format JSON DateTime in ASP.NET MVC?

                // THIS CALL WILL DO CUSTOM FORMATTING
                return WriteJson(model, JsonRequestBehavior.AllowGet);             
        }


        /// <summary>
        /// THIS CODE INSTALL CUSTOM FORMATTER
        /// AND WRITES IT TO RESPONSE STREAM
        /// </summary>
        /// <param name="data"></param>
        /// <param name="behavior"></param>
        /// <returns></returns>
        private ActionResult WriteJson(object data, JsonRequestBehavior behavior)
        {           
            HttpResponseBase response = ControllerContext.HttpContext.Response;
 
            response.ContentType =  "application/json";
           
            using (JsonTextWriter writer = new JsonTextWriter(response.Output) { Formatting = Formatting.Indented })
            {
                JsonSerializerSettings sett = new JsonSerializerSettings();
                // THIS INJECTS THE CUSTOM FORMATTER
                sett.Converters.Add(new UtcDateTimeConverter());
                JsonSerializer serializer = JsonSerializer.Create(sett);
              
                serializer.Serialize(writer, data);

                writer.Flush();
            }

            return null;
        }

using Newtonsoft.Json.Converters;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;

namespace Homag.MobileDashboard
{
    /// <summary>
    /// Implements the serialization and deserialization of
    /// DateTimeOffset type specified in ISO format.
    /// </summary>
    public class UtcDateTimeConverter : DateTimeConverterBase
    {
        /// <summary>
        /// holds ISO fromat to be used.
        /// </summary>
        public string DateTimeFormat { get; set; }

        /// <summary>
        /// Sets the default IDO format 'yyyy-MM-ddTHH:mm:ss'
        /// </summary>
        public UtcDateTimeConverter()
        {
            this.DateTimeFormat = "yyyy-MM-dd HH:mm:ss"; //PUT HERE ANY FORMAT YOU NEED!
        }


        /// <summary>
        /// Invoked when caller's data has to be deserialized. 
        /// </summary>
        /// <returns>The DateTimeOffset converted to UTC time.
        /// In this case the offset value is allways 0.</returns>
        public override object ReadJson(Newtonsoft.Json.JsonReader reader,
        Type objectType, object existingValue,
        Newtonsoft.Json.JsonSerializer serializer)
        {
            if (objectType == typeof(DateTime))
            {
                //SEE HERE WHY.
                throw new NotSupportedException("DateTime not allowed");
            }
            else if (objectType == typeof(DateTimeOffset))
            {
                reader.Read();// move to datetime element
                reader.Read();//move to datetime value
                DateTime dt = (DateTime)reader.Value;

                reader.Read();// move to offset element
                reader.Read();//move to offset value
                Int64 offsetinMin = (Int64)reader.Value;

                DateTime utcTime = new DateTime(dt.AddMinutes(-offsetinMin).Ticks,
                DateTimeKind.Utc);

                reader.Read();//ensures that reader is left in valid state.

                return new DateTimeOffset(utcTime, TimeSpan.FromMinutes(0));
            }
            else
                return null;
        }


        /// <summary>
        /// Invoked when data has to be serialized before sending to the caller.
        /// This method will fail if the service code tries to send DateTime 
        //  instead of DateTimeOffset.
        /// </summary>
        /// <param name="writer"></param>
        /// <param name="value"></param>
        /// <param name="serializer"></param>
        public override void WriteJson(Newtonsoft.Json.JsonWriter writer,
               object value,
               Newtonsoft.Json.JsonSerializer serializer)
        {
           // IF YOU WANT TO DEAL WITH DATETIME
            // THIS SHOWS HOW TO DO THAT
            if (value is DateTime)
            {
                DateTime utcTime = (DateTime)value;
                writer.WriteRawValue(String.Format("\"{0}\"",
               ((DateTime)utcTime.ToLocalTime()).ToString(this.DateTimeFormat)));               
            }
           // EXAMPLE OF DateTimeOffset formatting
            else if (value is DateTimeOffset)
            {
                DateTimeOffset offs = (DateTimeOffset)value;
                writer.WriteRawValue(String.Format("\"{0} UTC({1:##})\"",
                offs.ToString(this.DateTimeFormat), offs.Offset.Minutes));
            }
        }
    }
}