DateTime and Stopwatch value comparison

I'm trying to trigger the Stopwatch.reset(); if the elapsed time is equal to the time value stored in a DateTime object workDt by using the .equals() to compare the elapsed time of the stopwatch with the time of day stored in my DateTime object workDt.

Basically the onTapped event triggers my Stopwatch to start and updates a textblock with the current elapsed time.

I've then passed a user inputted time value "00 : 00 : 07 : 000" to a DateTime object which I'm aiming to use for the comparison. The problem is I the condition is never met to trigger myStopwatch.reset();

In testing I set the string as follows which I then set a break point on the workDt and it shows the correct time is being stored but it doesn't trigger the condition.

private async void startBtn_Tap(object sender, System.Windows.Input.GestureEventArgs e)
        {

            //delay stop watch start to allow time to get ready.
            TimeSpan time = TimeSpan.FromSeconds(1);
            await System.Threading.Tasks.Task.Delay(time);


            string wrkString;
            string rstString; 
            int i;

            //set text box editing to false to prevent illegal input.
            wrkTbx.IsEnabled = false;
            restTbx.IsEnabled = false;
            roundSlider.IsEnabled = false;
            roundsTbx.IsEnabled = false;


            //Assign text box time string to string variables.
            wrkString = wrkTbx.Text;
            rstString = restTbx.Text;


            //Assign text box string value to a date time variable.

            DateTime workDt = DateTime.ParseExact(wrkString.Replace(": ", ":").Replace(" :", ":"), "HH:mm:ss:fff", CultureInfo.InvariantCulture);
            DateTime restDt = DateTime.ParseExact(rstString.Replace(": ", ":").Replace(" :", ":"), "HH:mm:ss:fff", CultureInfo.InvariantCulture);

            //Run the timer for until i reaches the number of rounds value.Eg, 4 rounds
            //for (i = 0; i <= roundSlider.Value; i++ )
            //{

                StopGoCvs.Background = new SolidColorBrush(Colors.Green);
                //startSoundElmt.Play();
                // set up the timer
                myTimer = new DispatcherTimer();
                myTimer.Interval = new TimeSpan(0, 0, 0, 0, 1);
                myTimer.Tick += myTimer_Tick;


                // start both timers
                myTimer.Start();
                myStopwatch.Start();

                //reset timer if date time value is equal to current elapsed time.
                if(myStopwatch.Elapsed.Equals(workDt.TimeOfDay))
                {

                    myStopwatch.Reset();

                }






        }

Is this the correct way to achieve this or should I be using a different method?