title: std::put_time formats
body: <p>I want understand how to work std::put_time, and how can I get date stamp in "YYYY/MM/DD HH:MM:SS" format. Now I write somthing like this:</p>
  
  <pre><code>std::chrono::time_point&lt;std::chrono::system_clock&gt; now = std::chrono::system_clock::now();
          std::time_t now_c = std::chrono::system_clock::to_time_t(now - std::chrono::hours(24));
          std::cout  &lt;&lt; std::put_time(std::localtime(&amp;now_c), "%F %T") &lt;&lt; '\n';
  </code></pre>
  
  <p>and output is 2011-10-25 12:00:08, how can I get the date as 2011/10/25 12:00:08.</p>