code: public static Date addHours(Date date, int iHours) {
      Calendar dateTime = dateToCalendar(date);
      dateTime.add(Calendar.HOUR, iHours);
      return dateTime.getTime();
    }
docs: Adds the specified (signed) amount of hours to the given date. For
  example, to subtract 5 hours from the current date, you can
  achieve it by calling: <code>addHours(Date, -5)</code>.
  
  @param date   The time.
  @param iHours The amount of hours to add.
  
  @return A new date with the hours added.