title: How to get 18-digit current timestamp in Swift?
body: <p>I want to get current timestamp like this:</p>
  
  <pre><code>636110767775716756​
  </code></pre>
  
  <p>However, when I do : </p>
  
  <pre><code>NSDate().timeIntervalSince1970
  </code></pre>
  
  <p>It returns a value like this:</p>
  
  <pre><code>1475491615.71278
  </code></pre>
  
  <p>How do I access current time stamp ticks in the format I want? I check the dates from <a href="http://tickstodatetime.com/" rel="noreferrer">here:</a></p>