title: PHP perform action every X minutes
body: <p>I've made a PHP script that gets tweets from twitter and saves them to a file for use (as JSON).
  Problem is that I only get the tweets once when I execute the script, but I want to get it about every 4-5 minutes.</p>
  
  <p>I've looked into <code>sleep</code> but that just delays the browser and executes the action once.
  I want to be executed <strong>every</strong> 4 minutes, not just once after a delay.</p>
  
  <p>I looked into cron aswell but the server that I'm going to run my application on does not allow me to use cron.</p>
  
  <p>TL;DR: Anybody know a good way to execute a php script every X minutes after the first execution?</p>