title: CodeIgniter extend user's session expiration time
body: <p>Is it possible to extend user's session expiration time in CI. What I want to do is, by default every user's session cookie lasts for example 1 day, but every time user visits the site his session expiration time is extended by one more day.</p>
  
  <p>I don't know if it is a good idea to do this, maybe I should just set cookies life time for like a week and that's it?</p>