title: Get the local time from a UTC time
body: <p>Let's say I have a data set with the date, latitude, and longitude.</p>
  
  <pre><code>dt = data.table(date = c("2017-10-24 05:01:05",
                           "2017-10-24 05:01:57", 
                           "2017-10-24 05:02:54"),
                  lat = c(-6.2704925537109375,
                          -6.2704925537109375,
                          -6.2704925537109375),
                  long = c(106.5803680419922, 
                           106.5803680419922,
                           106.5803680419922))
  </code></pre>
  
  <p>The time is UTC. Is it possible to transfer that UTC to the local time using the lat and long? </p>