title: I am new to php and I need help understanding this code
body: <pre><code>$ep1 = mktime(19,32,56,5,10,1965);
  
  $ep2 = mktime(4,29,11,11,20,1962);
  echo($ep2);
  $diff_seconds = $ep1 - $ep2;
  
  $diff_weeks = floor($diff_seconds/604800); // 128 
  *$diff_seconds -= $diff_weeks * 604800;
  
  $diff_days = floor($diff_seconds/86400);
  *$diff_seconds -= $diff_days * 86400;
  
  
  $diff_hrs = floor($diff_seconds/3600);
  *$diff_seconds -= $diff_hrs * 3600;
  
  $diff_mins = floor($diff_seconds/60);
  *$diff_seconds -= $diff_mins * 60;
  echo('&lt;br&gt;');
  echo("Difference = $diff_weeks,$diff_days,$diff_hrs,$diff_mins");
  </code></pre>
  
  <p>I want to understand why the lines marked with an asterisks(*) has been done?
  Thank you</p>