title: Datediff for datetime in different time zones
body: <p>UPDATED</p>
  
  <p>I need to get the hour and minute difference between two datetimes that are in different time zones.</p>
  
  <p>I have the datetime in MySQL, and the offset from GMT, of the locations in MySQL.</p>
  
  <p>What I have tried:</p>
  
  <pre><code>&lt;cfset departure = CreateDateTime(2017,01,27,21,00,00)&gt; &lt;!--- (this time zone is +2) ---&gt;
  &lt;cfset arrival = CreateDateTime(2017,01,28,06,40,00)&gt; &lt;!--- (this time zone is -5) ---&gt;
  &lt;cfset depart_timezone = 2&gt;
  &lt;cfset arrive_timezone = -5&gt;
  
  &lt;cfset difference = datediff("h",departure,arrival)&gt;&lt;!--- get the difference in hours ---&gt;
  
  &lt;cfset timezonedif = depart_timezone - arrive_timezone&gt;&lt;!--- get the difference between the time zones (answer should be 7)---&gt;
  &lt;cfset duration = difference + timezonedif&gt;&lt;!--- add the time zone difference to the flight difference ---&gt;
  
  &lt;cfoutput&gt;          
  (Duration: #duration# hours)&lt;br&gt;
  &lt;/cfoutput&gt; 
  </code></pre>
  
  <p>This returns 16 hours which is not correct. The difference should be 15 hours and 40 minutes. Help will be appreciated. Been at this for hours.</p>