title: Convert Time from one time zone to another in Rails
body: <p>My <code>created_at</code> timestamps are stored in UTC:</p>
  
  <pre><code>&gt;&gt; Annotation.last.created_at
  =&gt; Sat, 29 Aug 2009 23:30:09 UTC +00:00
  </code></pre>
  
  <p>How do I convert one of them to 'Eastern Time (US &amp; Canada)' (taking into account daylight savings)? Something like:</p>
  
  <pre><code>Annotation.last.created_at.in_eastern_time
  </code></pre>