code: public static String naturalTime(final Date reference, final Date duration)
      {
          long diff = duration.getTime() - reference.getTime();
          return context.get().getDurationFormat().formatDurationFrom(diff, reference.getTime());
      }
docs: <p>
  Computes both past and future relative dates.
  </p>
  
  <p>
  E.g. "1 day ago", "1 day from now", "10 years ago", "3 minutes from now"
  and so on.
  </p>
  
  @param reference
  Date to be used as reference
  @param duration
  Date to be used as duration from reference
  @return String representing the relative date