title: Mongo db convert NumberLong(Unix timestamp) to Date
body: <p>im new to mongodb im trying to convert unix timestamp example 1514428475 to readable date time.</p>
  
  <p>i have tried using the mongodb shell but the result date is not correct it should be Dec 27 10:34am not Dec 28 12:51pm</p>
  
  <blockquote>
    <p>Date(NumberLong("1514428475"));
    Thu Dec 28 2017 12:51:58 GMT+0800 (HKT)</p>
  </blockquote>