title: Writing a cron expression to execute every 15 minutes
body: <p>I am trying to setup a cron job to run the garbage collector every 15 minutes on my session directory to clean up sessions that are beyond the expiration limit I set in php.ini, in one of my subdirectory locations. I have never used cron jobs before so I was wondering if someone could help me.</p>
  
  <p>What I have so far is:</p>
  
  <pre><code>15 * * * * /home/yadda/something/etc 
  </code></pre>