public class DateTimeJavaScriptConverter : JavaScriptConverter
{
  public override object Deserialize(IDictionary<string, object> dictionary, Type type, JavaScriptSerializer serializer)
  {
    return new JavaScriptSerializer().ConvertToType(dictionary, type);
  }
 
  public override IDictionary<string, object> Serialize(object obj, JavaScriptSerializer serializer)
  {
    if (!(obj is DateTime)) return null;
    return new CustomString(((DateTime)obj).ToUniversalTime().ToString("O"));
  }
 
  public override IEnumerable<Type> SupportedTypes
  {
    get { return new[] { typeof(DateTime) }; }
  }
 
  private class CustomString : Uri, IDictionary<string, object>
  {
    public CustomString(string str)
      : base(str, UriKind.Relative)
    {
    }
 
    void IDictionary<string, object>.Add(string key, object value)
    {
      throw new NotImplementedException();
    }
 
    bool IDictionary<string, object>.ContainsKey(string key)
    {
      throw new NotImplementedException();
    }
 
    ICollection<string> IDictionary<string, object>.Keys
    {
      get { throw new NotImplementedException(); }
    }
 
    bool IDictionary<string, object>.Remove(string key)
    {
      throw new NotImplementedException();
    }
 
    bool IDictionary<string, object>.TryGetValue(string key, out object value)
    {
      throw new NotImplementedException();
    }
 
    ICollection<object> IDictionary<string, object>.Values
    {
      get { throw new NotImplementedException(); }
    }
 
    object IDictionary<string, object>.this[string key]
    {
      get
      {
        throw new NotImplementedException();
      }
      set
      {
        throw new NotImplementedException();
      }
    }
 
    void ICollection<KeyValuePair<string, object>>.Add(KeyValuePair<string, object> item)
    {
      throw new NotImplementedException();
    }
 
    void ICollection<KeyValuePair<string, object>>.Clear()
    {
      throw new NotImplementedException();
    }
 
    bool ICollection<KeyValuePair<string, object>>.Contains(KeyValuePair<string, object> item)
    {
      throw new NotImplementedException();
    }
 
    void ICollection<KeyValuePair<string, object>>.CopyTo(KeyValuePair<string, object>[] array, int arrayIndex)
    {
      throw new NotImplementedException();
    }
 
    int ICollection<KeyValuePair<string, object>>.Count
    {
      get { throw new NotImplementedException(); }
    }
 
    bool ICollection<KeyValuePair<string, object>>.IsReadOnly
    {
      get { throw new NotImplementedException(); }
    }
 
    bool ICollection<KeyValuePair<string, object>>.Remove(KeyValuePair<string, object> item)
    {
      throw new NotImplementedException();
    }
 
    IEnumerator<KeyValuePair<string, object>> IEnumerable<KeyValuePair<string, object>>.GetEnumerator()
    {
      throw new NotImplementedException();
    }
 
    IEnumerator IEnumerable.GetEnumerator()
    {
      throw new NotImplementedException();
    }
  }
}