title: When do I need to use cron?
body: <p>Lets say there is a thread ( on forums ) which will be active for 3 days only. Now, after 3 days, I want this thread automatically closed.</p>
  
  <p>Can I use reference to time when this thread is created in database, and than make <strong>if</strong> statement if current date + days is bigger than date created, I will print out <code>"&lt;h2&gt;Thread Closed for posting&lt;/h2&gt;"</code></p>
  
  <p>And when I consider some other tasks, I suppose I can use reference to time and have certain event executed on this.</p>
  
  <p>Am I right? </p>