//Class

    class ExecutionTimer
    {
        //PRIVATE VARIABLES FOR HOLDING THE TIME INFORMATION
        private long startTime;
        private long stopTime;

        //DEFAULT CONSTRUCTOR JUST CALLS THE START TIMER
        public ExecutionTimer()
        {
            StartTimer();
        }

        /// <summary>
        /// MARK THE START TIME FOR CALCULATIONS
        /// </summary>
        public void StartTimer()
        {
            startTime = DateTime.Now.Ticks;
        }

        /// <summary>
        /// MARK THE STOP TIME FOR CALCULATIONS
        /// </summary>
        public void StopTimer()
        {
            stopTime = DateTime.Now.Ticks;
        }

        /// <summary>
        /// DEFAULT OVERRIDE OF TOSTRING TO FORMAT THE OUTPUT AS A VALID TIME STRING
        /// </summary>
        /// <returns>FORMATTED TIME STRING IN FORMAT OF HH:MM:SS.MILISECONDS</returns>
        public override string ToString()
        {
            return ToString(1);
        }

        /// <summary>
        /// OUTPUT THE STRING USING AN AVERAGE COUNTER INCASE THE USER RAN THE TRACKING MORE THEN ONCE WE NEED TO AVG THE TIME
        /// </summary>
        /// <param name="avg">DIVISOR</param>
        /// <returns>FORMATTED TIME STRING IN FORMAT OF HH:MM:SS.MILISECONDS AVERAGED OVER X ATTEMPTS</returns>
        public string ToString(long avg)
        {
            //VERIFY THAT AVG IS A VALID VALUE
            if (avg == 0)
                throw new ArgumentException("Avg can not be 0", "avg");

            //RETURN THE FORMATTED STRING FROM THE NEW DATE
            return string.Format("{0:HH:mm:ss.ff}", new DateTime((stopTime - startTime) / avg));
        }
    }

//Usage

    class Program
    {
        static void Main(string[] args)
        {
            ExecutionTimer tmpTimer = new ExecutionTimer();
            System.Threading.Thread.Sleep(5500);
            tmpTimer.StopTimer();
        }
    }