title: ini_set 'session.gc_maxlifetime' for 1 day
body: <p>If I do:</p>
  
  <pre><code>ini_set('session.gc_maxlifetime', 86400);
  </code></pre>
  
  <p>Does this mean the user can leave there browser on the same page (inactive) for up to 1 day without the worry of the session being garbage collected and them being logged out?</p>
  
  <p>What happens if the server configuration doesn't support this? (Will it give me an error? or just fail silently?)</p>
  
  <p>The default garbage collection time is 24 minutes which could happen in my system easily.</p>
  
  <p>Does garbage collection run on session_start?</p>