if (this.minute != LAST_MINUTE_IN_HOUR) {
            result = new Minute(this.minute + 1, getHour());
        }
        else { // we are at the last minute in the hour...
            Hour nextHour = (Hour) getHour().next();
            if (nextHour != null) {
                result = new Minute(FIRST_MINUTE_IN_HOUR, nextHour);
            }
            else {
                result = null;