title: PHP: Compare file timestamp with system time
body: <p>I am new to PHP and am writing a PHP script that contains <code>a module which reads the file timestamp out of a file and then compare with system time to see whether the file is older than 5 minutes or not and I am wondering how that can be achieved</code>. I am currently using</p>
  
  <pre><code>$timeStamp = strftime('%c', filectime($this-&gt;localPath));
  $timeStamp2 = filectime($this-&gt;localPath);
  </code></pre>
  
  <p>The two <code>$timeStamp</code> and <code>$timeStamp2</code> are different, the 1st one is more human readable</p>
  
  <pre><code>$timeStamp Mon Jun 20 15:17:01 2011
  $timeStamp2 1308608221 
  </code></pre>
  
  <p>What does <code>$timeStamp2</code> mean?</p>
  
  <p>And again, how to see if <code>the file is more than 5 minutes old?</code></p>