title: std::chrono::system_clock vs std::chrono::high_resolution_clock behavior
body: <p>Consider the following code snippet:</p>
  
  <pre><code>#include &lt;chrono&gt;
  #include &lt;cassert&gt;
  
  int main()
  {
       auto result1 = std::chrono::duration_cast&lt;std::chrono::seconds&gt;(std::chrono::high_resolution_clock::now().time_since_epoch());
       auto result2 = std::chrono::duration_cast&lt;std::chrono::seconds&gt;(std::chrono::system_clock::now().time_since_epoch());
       assert((result2.count() - result1.count()) &lt; 10);
  }
  </code></pre>
  
  <p>I am expecting that the difference in counts between the two values should be minimal (ideally less than a second). But with VS2015, the difference in count is of the order of Billions of seconds. How is this possible?</p>