title: How to convert UDate from one timezone to another using ICU
body: <p>After spending some significant amount of time, I could not figure out how to convert UDate from one timezone to another. Here is the problem I am trying to solve :</p>
  
  <p>I have a timestamp which is number of milliseconds since epoch. This is a timestamp in UTC. I want to convert this timestamp to a timestamp at some local time zone (e.g. US/Eastern). I want to extract number of days since epoch and number of milliseconds since from converted timestamp. I want to use icu library to do this.</p>
  
  <p>I tried to create a UDate from number of milliseconds since epoch in UTC. I can create a timezone instance for the given timezone.</p>
  
  <pre><code>TimeZone *tz = TimeZone::createTimeZone("US/Eastern");
  </code></pre>
  
  <p>How do I convert UDate from UTC to the given timezone and extract the answers I want? Could it be done using icu? 
  Any help will be greatly appreciated.</p>