Check out example codes for "c# stopwatch". It will help you in understanding the concepts better.

Code Example 1

var timer = new Stopwatch();

  timer.Start();
  // do stuff
  timer.Stop();
}

Code Example 2

private void timer1_Tick(object sender, EventArgs e)
{
    TimeSpan duration = DateTime.Now - _start;
    label3.Text = duration.ToString(<some format string>);
}

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