var obj = new Lad
{
firstName = "Markoff",
lastName = "Chaney",
dateOfBirth = new MyDate
{
year = 1901,
month = 4,
day = 30
}
};

var jsonString = Newtonsoft.Json.JsonConvert.SerializeObject(obj);

Deserializing to Object:

var obj = Newtonsoft.Json.JsonConvert.DeserializeObject<Lad>(jsonString );