title: How to add hours to Datetime in Zeppelin Spark Sql
body: <p>I have a query with a column that converts the universal datetime field (not a timestamp)  to a local time based on the the timezone.  In Oracle I was able to do this with intervals like this snippet below, but Spark wouldn't allow intervals. How can I do this in Spark.SQL?</p>
  
  <pre><code>case when c.timezone in (4,5) then to_char(b.universal_datetime + 
  
  NUMTODSINTERVAL(3, 'HOUR'),'yyyy/mm/dd HH24:MI:SS')
  when c.timezone in (8) then to_char(b.universal_datetime,'yyyy/mm/dd HH24:MI:SS')
  when c.timezone in (7) then to_char(b.universal_datetime + NUMTODSINTERVAL(1, 'HOUR'),'yyyy/mm/dd HH24:MI:SS')
  when c.timezone in (6) then to_char(b.universal_datetime + NUMTODSINTERVAL(2, 'HOUR'),'yyyy/mm/dd HH24:MI:SS')
  when c.timezone in (10) then to_char(b.universal_datetime - NUMTODSINTERVAL(3, 'HOUR'),'yyyy/mm/dd HH24:MI:SS')
  when c.timezone in (9) then to_char(b.universal_datetime - NUMTODSINTERVAL(1, 'HOUR'),'yyyy/mm/dd HH24:MI:SS')
  ELSE 'Other' END AS Local_Time, 
  </code></pre>