title: c++ chrono Clock in HH:MM:SS when it needs to be in seconds.milliseconds
body: <p>So right now, the code im using is </p>
  
  <pre><code>using std::chrono::system_clock;
  std::time_t tt = system_clock::to_time_t (system_clock::now());
  struct std::tm * ptm = std::localtime(&amp;tt);
  std::cout &lt;&lt; "Current time: " &lt;&lt; std::put_time(ptm,"%X") &lt;&lt; '\n';
  std::this_thread::sleep_for (std::chrono::seconds(7));
  </code></pre>
  
  <p>It is simple in that this is in a loop, and chrono sleep_for delays the system for however many seconds. 
  The problem is that it is in the HH:MM:SS format when I really need seconds.milliseconds to show the system clock transaction time. How would I do this? I really just need someone to explain the code, why is it making a struct? And what should I do to change the format? Thanks!</p>