title: Paperclip - How do they create the timestamp appended to the file name?
body: <p>I am using Paperclip to store images using S3. It's my understanding that Paperclip will append a string (timestamp) to the end of the image for caching purposes. Do you know what method they use to create the string? I need to rebuild it using .js, here's why:</p>
  
  <p>I am getting content using jQuery's $.getJSON, parsing the response data, building an array and adding it to the DOM. Everything works great with that, but I need to add the string on to the end of the file name.</p>
  
  <p>Here's an example:</p>
  
  <pre><code>&lt;img src="http://s3.amazonaws.com/some_bucket/some_image.jpg?1293603533" /&gt;
  </code></pre>
  
  <p>Although the URL is an example, the string appended to the file name is actual. Here is the other data on this image.</p>
  
  <pre><code>image_file_size: 159713 
  image_height: 415   
  image_width: 900    
  image_updated_at: 2010-12-29 06:18:53
  </code></pre>
  
  <p>I thought it'd be as easy as stripping all ":" and "-" from the image_updated_at attribute but it doesn't look that easy. Is it completely random? Anyone have any idea on this? I'd appreciate a hand!</p>