title: Header Cache Expire - dynamic site and ad server clicks?
body: <p>I did some research on speeding up your php mysql site. We update new information on our site every 12 to 24 hours.</p>
  
  <p>I found that Header Expire Cache Control in the browser helps speed up the site.</p>
  
  <p>Here is my code:</p>
  
  <pre><code>Header("Cache-Control: must-revalidate");
  
   $offset = 60 * 60 * 24 * 3;
   $ExpStr = "Expires: " . gmdate("D, d M Y H:i:s", time() + $offset) . " GMT";
   Header($ExpStr);
  </code></pre>
  
  <p>I am wondering, how do I change this to 1 hour instead of 3 days, also -- </p>
  
  <p>How are my ads on our site getting effected with browser cache enabled? Does it still count impressions and clicks?</p>