title: How to convert epoch to gregorian datetime in haskell
body: <p>Let's say I have an integer representing Epoch time, for example <code>epoch = 1499055085</code>, and I want to convert it to <code>UTCTime</code> in Haskell. 
  How can I do this?</p>
  
  <p>In other languages this is a very trivial task, why is it so difficult in haskell?</p>