title: measure elapsed time accounting day light saving
body: <p>I have code that measure how much time some operation took. If day light saving takes effect in the middle of the operation, I get inaccurate data.</p>
  
  <p>So for example, I am doing</p>
  
  <pre><code>DateTime startAt = DateTime.Now;
  DoOperation(); //day light saving takes effect in the middle
  int seconds = (DateTime.Now - startAt).TotalSeconds;
  //second has wrong seconds
  </code></pre>
  
  <p>Is there a way to measure this?</p>
  
  <p>Thanks</p>