code: public Date getPreviousWorkFinish(Date date)
     {
        Calendar cal = Calendar.getInstance();
        cal.setTime(date);
        updateToPreviousWorkFinish(cal);
        return cal.getTime();
     }
docs: Utility method to retrieve the previous working date finish time, given
  a date and time as a starting point.
  
  @param date date and time start point
  @return date and time of previous work finish