title: How to use ZoneOffset, ZoneId with LocalDateTime properly in Java 8?
body: <p>The objective here is to convert LocalDateTime to epoch second back and forth.</p>
  
  <p>Suppose I have a LocalDateTime defined as:</p>
  
  <pre><code>LocalDateTime now = LocalDateTime.now();
  </code></pre>
  
  <p>I want to convert it to epoch second in time Asia/Kolkata time zone which I can do like:</p>
  
  <pre><code>long epochSecondNow = now.atZone(ZoneId.of("Asia/Kolkata")).toEpochSecond();
  </code></pre>
  
  <p>Now, I want to generate the 'now' again from epochSecondNow:</p>
  
  <p>LocalDateTime class has a method '
  <code>ofEpochSecond(long epochSecond,long nanoOfSecond, ZoneOffset zoneOffset)</code>' which takes epoch second, nano of second and ZoneOffset as arguments.</p>
  
  <p>I am not able to create ZoneOffset using "Asia/Kolkata". How should I make the ZoneOffset object for my zone in order to make use of 'ofEpochSecond' method. 
  Is there any other way?</p>
  
  <p>Thanks!</p>