code: public final Timestamp addHour(int amount)
      {
          long delta = (long) amount * 60 * 60 * 1000;
          return addMillisForPrecision(delta, Precision.MINUTE, false);
      }
docs: Returns a timestamp relative to this one by the given number of hours.
  <p>
  This method always returns a Timestamp with at least MINUTE precision.
  For example, adding one hour to {@code 2011T} results in
  {@code 2011-01-01T01:00-00:00}. To receive a Timestamp that always
  maintains the same precision as the original, use {@link #adjustHour(int)}.
  
  @param amount a number of hours.