using System;

using Newtonsoft.Json;

using AutoFixture;

public class Program

{

    public static void Main()

    {

        var fixture = new Fixture();

        var autoGeneratedTimeSpan = fixture.Create<TimeSpan>();

        string json = JsonConvert.SerializeObject(autoGeneratedTimeSpan, Formatting.Indented);

        Console.WriteLine(json);

        var deserializedTimeSpan = JsonConvert.DeserializeObject<TimeSpan>(json);

        Console.WriteLine(deserializedTimeSpan);

        Console.WriteLine(JsonConvert.DeserializeObject<TimeSpan>("\"12\""));

        Console.WriteLine(JsonConvert.DeserializeObject<TimeSpan>("\"12:34\""));

        Console.WriteLine(JsonConvert.DeserializeObject<TimeSpan>("\"12:34:56\""));

    }

}

​