using System;

using System.Globalization;

public class Program

{

    public static void Main()

    {

        string timeFormat = @"hh\:mm\:ss\.fff";

        TimeSpan timeZero = TimeSpan.ParseExact("00:00:00.000", timeFormat, CultureInfo.InvariantCulture);

        Console.WriteLine(timeZero);

    }

}