title: How to convert Date to ZonedDateTime?
body: <p>I've got various <code>java.util.Date</code> objects with values of this format: <code>2014-01-21 10:28:57.122Z</code>. I would like to convert them all to <code>ZonedDateTime</code> objects. </p>
  
  <p>According to <a href="https://stackoverflow.com/questions/25376242/java8-java-util-date-conversion-to-java-time-zoneddatetime">this</a> SO question, and <a href="https://docs.oracle.com/javase/8/docs/api/java/time/ZonedDateTime.html#ofInstant-java.time.Instant-java.time.ZoneId-" rel="noreferrer"><code>ZonedDateTime</code>'s <code>ofInstant()</code></a>, one way is like so:  </p>
  
  <pre><code>ZonedDateTime z = ZonedDateTime.ofInstant(dateObject.toInstant(), ZoneId);
  </code></pre>
  
  <p>The problem is, how do I figure out what to use for the <code>ZoneId</code> parameter? I can't use my system time (<code>ZoneId.systemDefault()</code>) because my <code>Date</code> objects all have different timezones.</p>