title: How to convert an NSTimeInterval (seconds) into minutes
body: <p>I've got an amount of <code>seconds</code> that passed from a certain event. It's stored in a <code>NSTimeInterval</code> data type.</p>
  
  <p>I want to convert it into <code>minutes</code> and <code>seconds</code>.</p>
  
  <p>For example I have: "326.4" seconds and I want to convert it into the following string:
  "5:26".</p>
  
  <p>What is the best way to achieve this goal?</p>
  
  <p>Thanks.</p>