title: Why does joda DateTimeZone's getOffset() method require an "instant"?
body: <p>What I'm trying to do:</p>
  
  <p>From a DateTimeZone object, I'm trying to get the GMT offset in milliseconds. Example:</p>
  
  <pre><code>DateTimeZone gmt= // somehow get gmt zone object
  long offset = gmt.getOffsetSomehow(); // expect offset = 0
  
  DateTimeZone ny_est = // somehow get that time zone object representing "EST" offset of NY zone
  long offset = ny_est.getOffsetSomehow(); // expect offset = -18000000 = -5*60*60*1000
  
  DateTimeZone hkt = // somehow get HK time zone object
  long offset = hkt.getOffsetSomehow(); // expect offset = 28800000 = 8*60*60*1000
  </code></pre>
  
  <p>Joda's DateTimeZone object has a method called <a href="http://joda-time.sourceforge.net/apidocs/org/joda/time/DateTimeZone.html#getOffset%28long%29" rel="noreferrer">getOffset</a>, which accepts a parameter. Question:</p>
  
  <ol>
  <li>why does that method need a parameter? I would have expected the method to not expect any param, and simply behave how I want my fictitious "getOffsetSomehow()" method.</li>
  <li>How can I get the time zone objects in my snippet above?</li>
  <li>What actual method/snippet of code can get me the "offset" values I'm try to get?</li>
  </ol>