Program do zliczania różnicy czasu

DateTime dt1 = DateTime.ParseExact(time1, "HH:mm:ss", new DateTimeFormatInfo());
DateTime dt2 = DateTime.ParseExact(time2, "HH:mm:ss", new DateTimeFormatInfo());
TimeSpan ts = dt1.Subtract(dt2);

DateTime d1, d2 
... żeby nie pisać 
if(d1.Year==d2.year && d1.Month==d2.Month)

/// <summary>
        /// Zwraca różnicę czasu między dwiema godzinami
        /// </summary>
        /// <param name="time1">(HH:mm:ss)</param>
        /// <param name="time2">(HH:mm:ss)</param>
        /// <returns></returns>
        public TimeSpan difference(string time1, string time2)
        {
            string[] words1 = time1.Split(new char[] { ':' }, StringSplitOptions.RemoveEmptyEntries);
            if (words1.Count() != 3)
                throw new ArgumentException();
            TimeSpan t1 = new TimeSpan(
                    int.Parse(words1[0]), // godzina
                    int.Parse(words1[1]), // minuta
                    int.Parse(words1[2])); // sekunda

            string[] words2 = time2.Split(new char[] { ':' }, StringSplitOptions.RemoveEmptyEntries);
            if (words2.Count() != 3)
                throw new ArgumentException();
            TimeSpan t2 = new TimeSpan(
                    int.Parse(words2[0]), // godzina
                    int.Parse(words2[1]), // minuta
                    int.Parse(words2[2])); // sekunda

            return (t1.Ticks > t2.Ticks) ? new TimeSpan(t1.Ticks - t2.Ticks) : new TimeSpan(t2.Ticks - t1.Ticks);

        }

string time1 = "12:53:24";
string time2 = "13:58:12";
Console.WriteLine(difference(time1, time2).ToString());

                var timeFormat = "hh\\:mm\\:ss";
		var t1 = TimeSpan.ParseExact("12:35:57", timeFormat, CultureInfo.InvariantCulture);
		var t2 = TimeSpan.ParseExact("11:13:46", timeFormat, CultureInfo.InvariantCulture);
		
		var t3 = t1.Subtract(t2).Duration();			
		Console.WriteLine(t3); // 01:22:11

		var t4 = t2.Subtract(t1).Duration();
		Console.WriteLine(t4); // 01:22:11