Review

class FastDateFormat.Rule {
        /**
         * Appends the value of the specified calendar to the output buffer based on the rule implementation.
         * 
         * @param buffer the output buffer
         * @param calendar calendar to be appended
         */
        void appendTo(StringBuffer buffer, Calendar calendar);
}

class FastDateFormat.CharacterLiteral {
        /**
         * {@inheritDoc}
         */
        public void appendTo(StringBuffer buffer, Calendar calendar) {
            buffer.append(mValue);
        }
}

class FastDateFormat.StringLiteral {
        public void appendTo(StringBuffer buffer, Calendar calendar) {
            buffer.append(mValue);
        }
}

class FastDateFormat.TextField {
        public void appendTo(StringBuffer buffer, Calendar calendar) {
            buffer.append(mValues[calendar.get(mField)]);
        }
}

class FastDateFormat.UnpaddedNumberField {
        public void appendTo(StringBuffer buffer, Calendar calendar) {
            appendTo(buffer, calendar.get(mField));
        }
}

class FastDateFormat.UnpaddedMonthField {
        public void appendTo(StringBuffer buffer, Calendar calendar) {
            appendTo(buffer, calendar.get(Calendar.MONTH) + 1);
        }
}

class FastDateFormat.PaddedNumberField {
        public void appendTo(StringBuffer buffer, Calendar calendar) {
            appendTo(buffer, calendar.get(mField));
        }
}

class FastDateFormat.TwoDigitNumberField {
        public void appendTo(StringBuffer buffer, Calendar calendar) {
            appendTo(buffer, calendar.get(mField));
        }
}

class FastDateFormat.TwoDigitYearField {
        public void appendTo(StringBuffer buffer, Calendar calendar) {
            appendTo(buffer, calendar.get(Calendar.YEAR) % 100);
        }
}

class FastDateFormat.TwoDigitMonthField {
        public void appendTo(StringBuffer buffer, Calendar calendar) {
            appendTo(buffer, calendar.get(Calendar.MONTH) + 1);
        }
}

class FastDateFormat.TwelveHourField {
        public void appendTo(StringBuffer buffer, Calendar calendar) {
            int value = calendar.get(Calendar.HOUR);
            if (value == 0) {
                value = calendar.getLeastMaximum(Calendar.HOUR) + 1;
            }
            mRule.appendTo(buffer, value);
        }
}

class FastDateFormat.TwentyFourHourField {
        public void appendTo(StringBuffer buffer, Calendar calendar) {
            int value = calendar.get(Calendar.HOUR_OF_DAY);
            if (value == 0) {
                value = calendar.getMaximum(Calendar.HOUR_OF_DAY) + 1;
            }
            mRule.appendTo(buffer, value);
        }
}

class FastDateFormat.TimeZoneNameRule {
        public void appendTo(StringBuffer buffer, Calendar calendar) {
            if (mTimeZoneForced) {
                if (mTimeZone.useDaylightTime() && calendar.get(Calendar.DST_OFFSET) != 0) {
                    buffer.append(mDaylight);
                } else {
                    buffer.append(mStandard);
                }
            } else {
                TimeZone timeZone = calendar.getTimeZone();
                if (timeZone.useDaylightTime() && calendar.get(Calendar.DST_OFFSET) != 0) {
                    buffer.append(getTimeZoneDisplay(timeZone, true, mStyle, mLocale));
                } else {
                    buffer.append(getTimeZoneDisplay(timeZone, false, mStyle, mLocale));
                }
            }
        }
}

class FastDateFormat.TimeZoneNumberRule {
        public void appendTo(StringBuffer buffer, Calendar calendar) {
            int offset = calendar.get(Calendar.ZONE_OFFSET) + calendar.get(Calendar.DST_OFFSET);
            
            if (offset < 0) {
                buffer.append('-');
                offset = -offset;
            } else {
                buffer.append('+');
            }
            
            int hours = offset / (60 * 60 * 1000);
            buffer.append((char)(hours / 10 + '0'));
            buffer.append((char)(hours % 10 + '0'));
            
            if (mColon) {
                buffer.append(':');
            }
            
            int minutes = offset / (60 * 1000) - 60 * hours;
            buffer.append((char)(minutes / 10 + '0'));
            buffer.append((char)(minutes % 10 + '0'));
        }            

}