Back to index...

	/*
	* Copyright (c) 2005, 2021, Oracle and/or its affiliates. All rights reserved.
	* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
	*
	* This code is free software; you can redistribute it and/or modify it
	* under the terms of the GNU General Public License version 2 only, as
	* published by the Free Software Foundation. Oracle designates this
	* particular file as subject to the "Classpath" exception as provided
	* by Oracle in the LICENSE file that accompanied this code.
	*
	* This code is distributed in the hope that it will be useful, but WITHOUT
	* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
	* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
	* version 2 for more details (a copy is included in the LICENSE file that
	* accompanied this code).
	*
	* You should have received a copy of the GNU General Public License version
	* 2 along with this work; if not, write to the Free Software Foundation,
	* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
	*
	* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
	* or visit www.oracle.com if you need additional information or have any
	* questions.
	*/

	package java.util;

	import java.io.IOException;
	import java.io.ObjectInputStream;
	import sun.util.locale.provider.CalendarDataUtility;
	import sun.util.calendar.BaseCalendar;
	import sun.util.calendar.CalendarDate;
	import sun.util.calendar.CalendarSystem;
	import sun.util.calendar.CalendarUtils;
	import sun.util.calendar.Era;
	import sun.util.calendar.Gregorian;
	import sun.util.calendar.LocalGregorianCalendar;
	import sun.util.calendar.ZoneInfo;

	/**
	* {@code JapaneseImperialCalendar} implements a Japanese
	* calendar system in which the imperial era-based year numbering is
	* supported from the Meiji era. The following are the eras supported
	* by this calendar system.
	* <pre>{@code
	* ERA value Era name Since (in Gregorian)
	* ------------------------------------------------------
	* 0 N/A N/A
	* 1 Meiji 1868-01-01T00:00:00 local time
	* 2 Taisho 1912-07-30T00:00:00 local time
	* 3 Showa 1926-12-25T00:00:00 local time
	* 4 Heisei 1989-01-08T00:00:00 local time
	* 5 Reiwa 2019-05-01T00:00:00 local time
	* ------------------------------------------------------
	* }</pre>
	*
	* <p>{@code ERA} value 0 specifies the years before Meiji and
	* the Gregorian year values are used. Unlike
	* {@link GregorianCalendar}, the Julian to Gregorian transition is not
	* supported because it doesn't make any sense to the Japanese
	* calendar systems used before Meiji. To represent the years before
	* Gregorian year 1, 0 and negative values are used. The Japanese
	* Imperial rescripts and government decrees don't specify how to deal
	* with time differences for applying the era transitions. This
	* calendar implementation assumes local time for all transitions.
	*
	* <p>A new era can be specified using property
	* jdk.calendar.japanese.supplemental.era. The new era is added to the
	* predefined eras. The syntax of the property is as follows.
	* <pre>
	* {@code name=<name>,abbr=<abbr>,since=<time['u']>}
	* </pre>
	* where
	* <dl>
	* <dt>{@code <name>:}<dd>the full name of the new era (non-ASCII characters allowed,
	* either in platform's native encoding or in Unicode escape notation, {@code \\uXXXX})
	* <dt>{@code <abbr>:}<dd>the abbreviation of the new era (non-ASCII characters allowed,
	* either in platform's native encoding or in Unicode escape notation, {@code \\uXXXX})
	* <dt>{@code <time['u']>:}<dd>the start time of the new era represented by
	* milliseconds from 1970-01-01T00:00:00 local time or UTC if {@code 'u'} is
	* appended to the milliseconds value. (ASCII digits only)
	* </dl>
	*
	* <p>If the given era is invalid, such as the since value before the
	* beginning of the last predefined era, the given era will be
	* ignored.
	*
	* <p>The following is an example of the property usage.
	* <pre>
	* java -Djdk.calendar.japanese.supplemental.era="name=NewEra,abbr=N,since=253374307200000"
	* </pre>
	* The property specifies an era change to NewEra at 9999-02-11T00:00:00 local time.
	*
	* @author Masayoshi Okutsu
	* @since 1.6
	*/
	class JapaneseImperialCalendar extends Calendar {
	/*
	* Implementation Notes
	*
	* This implementation uses
	* sun.util.calendar.LocalGregorianCalendar to perform most of the
	* calendar calculations.
	*/

	/**
	* The ERA constant designating the era before Meiji.
	*/
	public static final int BEFORE_MEIJI = 0;

	/**
	* The ERA constant designating the Meiji era.
	*/
	public static final int MEIJI = 1;

	/**
	* The ERA constant designating the Taisho era.
	*/
	public static final int TAISHO = 2;

	/**
	* The ERA constant designating the Showa era.
	*/
	public static final int SHOWA = 3;

	/**
	* The ERA constant designating the Heisei era.
	*/
	public static final int HEISEI = 4;

	/**
	* The ERA constant designating the Reiwa era.
	*/
	private static final int REIWA = 5;

	private static final int EPOCH_OFFSET = 719163; // Fixed date of January 1, 1970 (Gregorian)

	// Useful millisecond constants. Although ONE_DAY and ONE_WEEK can fit
	// into ints, they must be longs in order to prevent arithmetic overflow
	// when performing (bug 4173516).
	private static final int ONE_SECOND = 1000;
	private static final int ONE_MINUTE = 60*ONE_SECOND;
	private static final int ONE_HOUR = 60*ONE_MINUTE;
	private static final long ONE_DAY = 24*ONE_HOUR;

	// Reference to the sun.util.calendar.LocalGregorianCalendar instance (singleton).
	private static final LocalGregorianCalendar jcal
	= (LocalGregorianCalendar) CalendarSystem.forName("japanese");

	// Gregorian calendar instance. This is required because era
	// transition dates are given in Gregorian dates.
	private static final Gregorian gcal = CalendarSystem.getGregorianCalendar();

	// The Era instance representing "before Meiji".
	private static final Era BEFORE_MEIJI_ERA = new Era("BeforeMeiji", "BM", Long.MIN_VALUE, false);

	// Imperial eras. The sun.util.calendar.LocalGregorianCalendar
	// doesn't have an Era representing before Meiji, which is
	// inconvenient for a Calendar. So, era[0] is a reference to
	// BEFORE_MEIJI_ERA.
	private static final Era[] eras;

	// Fixed date of the first date of each era.
	private static final long[] sinceFixedDates;

	// The current era
	private static final int currentEra;

	/*
	* <pre>
	* Greatest Least
	* Field name Minimum Minimum Maximum Maximum
	* ---------- ------- ------- ------- -------
	* ERA 0 0 1 1
	* YEAR -292275055 1 ? ?
	* MONTH 0 0 11 11
	* WEEK_OF_YEAR 1 1 52* 53
	* WEEK_OF_MONTH 0 0 4* 6
	* DAY_OF_MONTH 1 1 28* 31
	* DAY_OF_YEAR 1 1 365* 366
	* DAY_OF_WEEK 1 1 7 7
	* DAY_OF_WEEK_IN_MONTH -1 -1 4* 6
	* AM_PM 0 0 1 1
	* HOUR 0 0 11 11
	* HOUR_OF_DAY 0 0 23 23
	* MINUTE 0 0 59 59
	* SECOND 0 0 59 59
	* MILLISECOND 0 0 999 999
	* ZONE_OFFSET -13:00 -13:00 14:00 14:00
	* DST_OFFSET 0:00 0:00 0:20 2:00
	* </pre>
	* *: depends on eras
	*/
	static final int MIN_VALUES[] = {
	0, // ERA
	-292275055, // YEAR
	JANUARY, // MONTH
	1, // WEEK_OF_YEAR
	0, // WEEK_OF_MONTH
	1, // DAY_OF_MONTH
	1, // DAY_OF_YEAR
	SUNDAY, // DAY_OF_WEEK
	1, // DAY_OF_WEEK_IN_MONTH
	AM, // AM_PM
	0, // HOUR
	0, // HOUR_OF_DAY
	0, // MINUTE
	0, // SECOND
	0, // MILLISECOND
	-13*ONE_HOUR, // ZONE_OFFSET (UNIX compatibility)
	0 // DST_OFFSET
	};
	static final int LEAST_MAX_VALUES[] = {
	0, // ERA (initialized later)
	0, // YEAR (initialized later)
	JANUARY, // MONTH (Showa 64 ended in January.)
	0, // WEEK_OF_YEAR (Showa 1 has only 6 days which could be 0 weeks.)
	4, // WEEK_OF_MONTH
	28, // DAY_OF_MONTH
	0, // DAY_OF_YEAR (initialized later)
	SATURDAY, // DAY_OF_WEEK
	4, // DAY_OF_WEEK_IN
	PM, // AM_PM
	11, // HOUR
	23, // HOUR_OF_DAY
	59, // MINUTE
	59, // SECOND
	999, // MILLISECOND
	14*ONE_HOUR, // ZONE_OFFSET
	20*ONE_MINUTE // DST_OFFSET (historical least maximum)
	};
	static final int MAX_VALUES[] = {
	0, // ERA
	292278994, // YEAR
	DECEMBER, // MONTH
	53, // WEEK_OF_YEAR
	6, // WEEK_OF_MONTH
	31, // DAY_OF_MONTH
	366, // DAY_OF_YEAR
	SATURDAY, // DAY_OF_WEEK
	6, // DAY_OF_WEEK_IN
	PM, // AM_PM
	11, // HOUR
	23, // HOUR_OF_DAY
	59, // MINUTE
	59, // SECOND
	999, // MILLISECOND
	14*ONE_HOUR, // ZONE_OFFSET
	2*ONE_HOUR // DST_OFFSET (double summer time)
	};

	// Proclaim serialization compatibility with JDK 1.6
	@SuppressWarnings("FieldNameHidesFieldInSuperclass")
	@java.io.Serial
	private static final long serialVersionUID = -3364572813905467929L;

	static {
	Era[] es = jcal.getEras();
	int length = es.length + 1;
	eras = new Era[length];
	sinceFixedDates = new long[length];

	// eras[BEFORE_MEIJI] and sinceFixedDate[BEFORE_MEIJI] are the
	// same as Gregorian.
	int index = BEFORE_MEIJI;
	int current = index;
	sinceFixedDates[index] = gcal.getFixedDate(BEFORE_MEIJI_ERA.getSinceDate());
	eras[index++] = BEFORE_MEIJI_ERA;
	for (Era e : es) {
	if(e.getSince(TimeZone.NO_TIMEZONE) < System.currentTimeMillis()) {
	current = index;
	}
	CalendarDate d = e.getSinceDate();
	sinceFixedDates[index] = gcal.getFixedDate(d);
	eras[index++] = e;
	}
	currentEra = current;

	LEAST_MAX_VALUES[ERA] = MAX_VALUES[ERA] = eras.length - 1;

	// Calculate the least maximum year and least day of Year
	// values. The following code assumes that there's at most one
	// era transition in a Gregorian year.
	int year = Integer.MAX_VALUE;
	int dayOfYear = Integer.MAX_VALUE;
	CalendarDate date = gcal.newCalendarDate(TimeZone.NO_TIMEZONE);
	for (int i = 1; i < eras.length; i++) {
	long fd = sinceFixedDates[i];
	CalendarDate transitionDate = eras[i].getSinceDate();
	date.setDate(transitionDate.getYear(), BaseCalendar.JANUARY, 1);
	long fdd = gcal.getFixedDate(date);
	if (fd != fdd) {
	dayOfYear = Math.min((int)(fd - fdd) + 1, dayOfYear);
	}
	date.setDate(transitionDate.getYear(), BaseCalendar.DECEMBER, 31);
	fdd = gcal.getFixedDate(date);
	if (fd != fdd) {
	dayOfYear = Math.min((int)(fdd - fd) + 1, dayOfYear);
	}
	LocalGregorianCalendar.Date lgd = getCalendarDate(fd - 1);
	int y = lgd.getYear();
	// Unless the first year starts from January 1, the actual
	// max value could be one year short. For example, if it's
	// Showa 63 January 8, 63 is the actual max value since
	// Showa 64 January 8 doesn't exist.
	if (!(lgd.getMonth() == BaseCalendar.JANUARY && lgd.getDayOfMonth() == 1)) {
	y--;
	}
	year = Math.min(y, year);
	}
	LEAST_MAX_VALUES[YEAR] = year; // Max year could be smaller than this value.
	LEAST_MAX_VALUES[DAY_OF_YEAR] = dayOfYear;
	}

	/**
	* jdate always has a sun.util.calendar.LocalGregorianCalendar.Date instance to
	* avoid overhead of creating it for each calculation.
	*/
	private transient LocalGregorianCalendar.Date jdate;

	/**
	* Temporary int[2] to get time zone offsets. zoneOffsets[0] gets
	* the GMT offset value and zoneOffsets[1] gets the daylight saving
	* value.
	*/
	private transient int[] zoneOffsets;

	/**
	* Temporary storage for saving original fields[] values in
	* non-lenient mode.
	*/
	private transient int[] originalFields;

	/**
	* Constructs a {@code JapaneseImperialCalendar} based on the current time
	* in the given time zone with the given locale.
	*
	* @param zone the given time zone.
	* @param aLocale the given locale.
	*/
	JapaneseImperialCalendar(TimeZone zone, Locale aLocale) {
	super(zone, aLocale);
	jdate = jcal.newCalendarDate(zone);
	setTimeInMillis(System.currentTimeMillis());
	}

	/**
	* Constructs an "empty" {@code JapaneseImperialCalendar}.
	*
	* @param zone the given time zone
	* @param aLocale the given locale
	* @param flag the flag requesting an empty instance
	*/
	JapaneseImperialCalendar(TimeZone zone, Locale aLocale, boolean flag) {
	super(zone, aLocale);
	jdate = jcal.newCalendarDate(zone);
	}

	/**
	* Returns {@code "japanese"} as the calendar type of this {@code
	* JapaneseImperialCalendar}.
	*
	* @return {@code "japanese"}
	*/
	@Override
	public String getCalendarType() {
	return "japanese";
	}

	/**
	* Compares this {@code JapaneseImperialCalendar} to the specified
	* {@code Object}. The result is {@code true} if and
	* only if the argument is a {@code JapaneseImperialCalendar} object
	* that represents the same time value (millisecond offset from
	* the <a href="Calendar.html#Epoch">Epoch</a>) under the same
	* {@code Calendar} parameters.
	*
	* @param obj the object to compare with.
	* @return {@code true} if this object is equal to {@code obj};
	* {@code false} otherwise.
	* @see Calendar#compareTo(Calendar)
	*/
	@Override
	public boolean equals(Object obj) {
	return obj instanceof JapaneseImperialCalendar &&
	super.equals(obj);
	}

	/**
	* Generates the hash code for this
	* {@code JapaneseImperialCalendar} object.
	*/
	@Override
	public int hashCode() {
	return super.hashCode() ^ jdate.hashCode();
	}

	/**
	* Adds the specified (signed) amount of time to the given calendar field,
	* based on the calendar's rules.
	*
	* <p><em>Add rule 1</em>. The value of {@code field}
	* after the call minus the value of {@code field} before the
	* call is {@code amount}, modulo any overflow that has occurred in
	* {@code field}. Overflow occurs when a field value exceeds its
	* range and, as a result, the next larger field is incremented or
	* decremented and the field value is adjusted back into its range.</p>
	*
	* <p><em>Add rule 2</em>. If a smaller field is expected to be
	* invariant, but it is impossible for it to be equal to its
	* prior value because of changes in its minimum or maximum after
	* {@code field} is changed, then its value is adjusted to be as close
	* as possible to its expected value. A smaller field represents a
	* smaller unit of time. {@code HOUR} is a smaller field than
	* {@code DAY_OF_MONTH}. No adjustment is made to smaller fields
	* that are not expected to be invariant. The calendar system
	* determines what fields are expected to be invariant.</p>
	*
	* @param field the calendar field.
	* @param amount the amount of date or time to be added to the field.
	* @throws IllegalArgumentException if {@code field} is
	* {@code ZONE_OFFSET}, {@code DST_OFFSET}, or unknown,
	* or if any calendar fields have out-of-range values in
	* non-lenient mode.
	*/
	@Override
	public void add(int field, int amount) {
	// If amount == 0, do nothing even the given field is out of
	// range. This is tested by JCK.
	if (amount == 0) {
	return; // Do nothing!
	}

	if (field < 0 \|\| field >= ZONE_OFFSET) {
	throw new IllegalArgumentException();
	}

	// Sync the time and calendar fields.
	complete();

	if (field == YEAR) {
	LocalGregorianCalendar.Date d = (LocalGregorianCalendar.Date) jdate.clone();
	d.addYear(amount);
	pinDayOfMonth(d);
	set(ERA, getEraIndex(d));
	set(YEAR, d.getYear());
	set(MONTH, d.getMonth() - 1);
	set(DAY_OF_MONTH, d.getDayOfMonth());
	} else if (field == MONTH) {
	LocalGregorianCalendar.Date d = (LocalGregorianCalendar.Date) jdate.clone();
	d.addMonth(amount);
	pinDayOfMonth(d);
	set(ERA, getEraIndex(d));
	set(YEAR, d.getYear());
	set(MONTH, d.getMonth() - 1);
	set(DAY_OF_MONTH, d.getDayOfMonth());
	} else if (field == ERA) {
	int era = internalGet(ERA) + amount;
	if (era < 0) {
	era = 0;
	} else if (era > eras.length - 1) {
	era = eras.length - 1;
	}
	set(ERA, era);
	} else {
	long delta = amount;
	long timeOfDay = 0;
	switch (field) {
	// Handle the time fields here. Convert the given
	// amount to milliseconds and call setTimeInMillis.
	case HOUR:
	case HOUR_OF_DAY:
	delta = 60 60 * 1000; // hours to milliseconds
	break;

	case MINUTE:
	delta = 60 1000; // minutes to milliseconds
	break;

	case SECOND:
	delta *= 1000; // seconds to milliseconds
	break;

	case MILLISECOND:
	break;

	// Handle week, day and AM_PM fields which involves
	// time zone offset change adjustment. Convert the
	// given amount to the number of days.
	case WEEK_OF_YEAR:
	case WEEK_OF_MONTH:
	case DAY_OF_WEEK_IN_MONTH:
	delta *= 7;
	break;

	case DAY_OF_MONTH: // synonym of DATE
	case DAY_OF_YEAR:
	case DAY_OF_WEEK:
	break;

	case AM_PM:
	// Convert the amount to the number of days (delta)
	// and +12 or -12 hours (timeOfDay).
	delta = amount / 2;
	timeOfDay = 12 * (amount % 2);
	break;
	}

	// The time fields don't require time zone offset change
	// adjustment.
	if (field >= HOUR) {
	setTimeInMillis(time + delta);
	return;
	}

	// The rest of the fields (week, day or AM_PM fields)
	// require time zone offset (both GMT and DST) change
	// adjustment.

	// Translate the current time to the fixed date and time
	// of the day.
	long fd = cachedFixedDate;
	timeOfDay += internalGet(HOUR_OF_DAY);
	timeOfDay *= 60;
	timeOfDay += internalGet(MINUTE);
	timeOfDay *= 60;
	timeOfDay += internalGet(SECOND);
	timeOfDay *= 1000;
	timeOfDay += internalGet(MILLISECOND);
	if (timeOfDay >= ONE_DAY) {
	fd++;
	timeOfDay -= ONE_DAY;
	} else if (timeOfDay < 0) {
	fd--;
	timeOfDay += ONE_DAY;
	}

	fd += delta; // fd is the expected fixed date after the calculation
	int zoneOffset = internalGet(ZONE_OFFSET) + internalGet(DST_OFFSET);
	setTimeInMillis((fd - EPOCH_OFFSET) * ONE_DAY + timeOfDay - zoneOffset);
	zoneOffset -= internalGet(ZONE_OFFSET) + internalGet(DST_OFFSET);
	// If the time zone offset has changed, then adjust the difference.
	if (zoneOffset != 0) {
	setTimeInMillis(time + zoneOffset);
	long fd2 = cachedFixedDate;
	// If the adjustment has changed the date, then take
	// the previous one.
	if (fd2 != fd) {
	setTimeInMillis(time - zoneOffset);
	}
	}
	}
	}

	@Override
	public void roll(int field, boolean up) {
	roll(field, up ? +1 : -1);
	}

	/**
	* Adds a signed amount to the specified calendar field without changing larger fields.
	* A negative roll amount means to subtract from field without changing
	* larger fields. If the specified amount is 0, this method performs nothing.
	*
	* <p>This method calls {@link #complete()} before adding the
	* amount so that all the calendar fields are normalized. If there
	* is any calendar field having an out-of-range value in non-lenient mode, then an
	* {@code IllegalArgumentException} is thrown.
	*
	* @param field the calendar field.
	* @param amount the signed amount to add to {@code field}.
	* @throws IllegalArgumentException if {@code field} is
	* {@code ZONE_OFFSET}, {@code DST_OFFSET}, or unknown,
	* or if any calendar fields have out-of-range values in
	* non-lenient mode.
	* @see #roll(int,boolean)
	* @see #add(int,int)
	* @see #set(int,int)
	*/
	@Override
	public void roll(int field, int amount) {
	// If amount == 0, do nothing even the given field is out of
	// range. This is tested by JCK.
	if (amount == 0) {
	return;
	}

	if (field < 0 \|\| field >= ZONE_OFFSET) {
	throw new IllegalArgumentException();
	}

	// Sync the time and calendar fields.
	complete();

	int min = getMinimum(field);
	int max = getMaximum(field);

	switch (field) {
	case ERA:
	case AM_PM:
	case MINUTE:
	case SECOND:
	case MILLISECOND:
	// These fields are handled simply, since they have fixed
	// minima and maxima. Other fields are complicated, since
	// the range within they must roll varies depending on the
	// date, a time zone and the era transitions.
	break;

	case HOUR:
	case HOUR_OF_DAY:
	{
	int unit = max + 1; // 12 or 24 hours
	int h = internalGet(field);
	int nh = (h + amount) % unit;
	if (nh < 0) {
	nh += unit;
	}
	time += ONE_HOUR * (nh - h);

	// The day might have changed, which could happen if
	// the daylight saving time transition brings it to
	// the next day, although it's very unlikely. But we
	// have to make sure not to change the larger fields.
	CalendarDate d = jcal.getCalendarDate(time, getZone());
	if (internalGet(DAY_OF_MONTH) != d.getDayOfMonth()) {
	d.setEra(jdate.getEra());
	d.setDate(internalGet(YEAR),
	internalGet(MONTH) + 1,
	internalGet(DAY_OF_MONTH));
	if (field == HOUR) {
	assert (internalGet(AM_PM) == PM);
	d.addHours(+12); // restore PM
	}
	time = jcal.getTime(d);
	}
	int hourOfDay = d.getHours();
	internalSet(field, hourOfDay % unit);
	if (field == HOUR) {
	internalSet(HOUR_OF_DAY, hourOfDay);
	} else {
	internalSet(AM_PM, hourOfDay / 12);
	internalSet(HOUR, hourOfDay % 12);
	}

	// Time zone offset and/or daylight saving might have changed.
	int zoneOffset = d.getZoneOffset();
	int saving = d.getDaylightSaving();
	internalSet(ZONE_OFFSET, zoneOffset - saving);
	internalSet(DST_OFFSET, saving);
	return;
	}

	case YEAR:
	min = getActualMinimum(field);
	max = getActualMaximum(field);
	break;

	case MONTH:
	// Rolling the month involves both pinning the final value to [0, 11]
	// and adjusting the DAY_OF_MONTH if necessary. We only adjust the
	// DAY_OF_MONTH if, after updating the MONTH field, it is illegal.
	// E.g., <jan31>.roll(MONTH, 1) -> <feb28> or <feb29>.
	{
	if (!isTransitionYear(jdate.getNormalizedYear())) {
	int year = jdate.getYear();
	if (year == getMaximum(YEAR)) {
	CalendarDate jd = jcal.getCalendarDate(time, getZone());
	CalendarDate d = jcal.getCalendarDate(Long.MAX_VALUE, getZone());
	max = d.getMonth() - 1;
	int n = getRolledValue(internalGet(field), amount, min, max);
	if (n == max) {
	// To avoid overflow, use an equivalent year.
	jd.addYear(-400);
	jd.setMonth(n + 1);
	if (jd.getDayOfMonth() > d.getDayOfMonth()) {
	jd.setDayOfMonth(d.getDayOfMonth());
	jcal.normalize(jd);
	}
	if (jd.getDayOfMonth() == d.getDayOfMonth()
	&& jd.getTimeOfDay() > d.getTimeOfDay()) {
	jd.setMonth(n + 1);
	jd.setDayOfMonth(d.getDayOfMonth() - 1);
	jcal.normalize(jd);
	// Month may have changed by the normalization.
	n = jd.getMonth() - 1;
	}
	set(DAY_OF_MONTH, jd.getDayOfMonth());
	}
	set(MONTH, n);
	} else if (year == getMinimum(YEAR)) {
	CalendarDate jd = jcal.getCalendarDate(time, getZone());
	CalendarDate d = jcal.getCalendarDate(Long.MIN_VALUE, getZone());
	min = d.getMonth() - 1;
	int n = getRolledValue(internalGet(field), amount, min, max);
	if (n == min) {
	// To avoid underflow, use an equivalent year.
	jd.addYear(+400);
	jd.setMonth(n + 1);
	if (jd.getDayOfMonth() < d.getDayOfMonth()) {
	jd.setDayOfMonth(d.getDayOfMonth());
	jcal.normalize(jd);
	}
	if (jd.getDayOfMonth() == d.getDayOfMonth()
	&& jd.getTimeOfDay() < d.getTimeOfDay()) {
	jd.setMonth(n + 1);
	jd.setDayOfMonth(d.getDayOfMonth() + 1);
	jcal.normalize(jd);
	// Month may have changed by the normalization.
	n = jd.getMonth() - 1;
	}
	set(DAY_OF_MONTH, jd.getDayOfMonth());
	}
	set(MONTH, n);
	} else {
	int mon = (internalGet(MONTH) + amount) % 12;
	if (mon < 0) {
	mon += 12;
	}
	set(MONTH, mon);

	// Keep the day of month in the range. We
	// don't want to spill over into the next
	// month; e.g., we don't want jan31 + 1 mo ->
	// feb31 -> mar3.
	int monthLen = monthLength(mon);
	if (internalGet(DAY_OF_MONTH) > monthLen) {
	set(DAY_OF_MONTH, monthLen);
	}
	}
	} else {
	int eraIndex = getEraIndex(jdate);
	CalendarDate transition = null;
	if (jdate.getYear() == 1) {
	transition = eras[eraIndex].getSinceDate();
	min = transition.getMonth() - 1;
	} else {
	if (eraIndex < eras.length - 1) {
	transition = eras[eraIndex + 1].getSinceDate();
	if (transition.getYear() == jdate.getNormalizedYear()) {
	max = transition.getMonth() - 1;
	if (transition.getDayOfMonth() == 1) {
	max--;
	}
	}
	}
	}

	if (min == max) {
	// The year has only one month. No need to
	// process further. (Showa Gan-nen (year 1)
	// and the last year have only one month.)
	return;
	}
	int n = getRolledValue(internalGet(field), amount, min, max);
	set(MONTH, n);
	if (n == min) {
	if (!(transition.getMonth() == BaseCalendar.JANUARY
	&& transition.getDayOfMonth() == 1)) {
	if (jdate.getDayOfMonth() < transition.getDayOfMonth()) {
	set(DAY_OF_MONTH, transition.getDayOfMonth());
	}
	}
	} else if (n == max && (transition.getMonth() - 1 == n)) {
	int dom = transition.getDayOfMonth();
	if (jdate.getDayOfMonth() >= dom) {
	set(DAY_OF_MONTH, dom - 1);
	}
	}
	}
	return;
	}

	case WEEK_OF_YEAR:
	{
	int y = jdate.getNormalizedYear();
	max = getActualMaximum(WEEK_OF_YEAR);
	set(DAY_OF_WEEK, internalGet(DAY_OF_WEEK)); // update stamp[field]
	int woy = internalGet(WEEK_OF_YEAR);
	int value = woy + amount;
	if (!isTransitionYear(jdate.getNormalizedYear())) {
	int year = jdate.getYear();
	if (year == getMaximum(YEAR)) {
	max = getActualMaximum(WEEK_OF_YEAR);
	} else if (year == getMinimum(YEAR)) {
	min = getActualMinimum(WEEK_OF_YEAR);
	max = getActualMaximum(WEEK_OF_YEAR);
	if (value > min && value < max) {
	set(WEEK_OF_YEAR, value);
	return;
	}

	}
	// If the new value is in between min and max
	// (exclusive), then we can use the value.
	if (value > min && value < max) {
	set(WEEK_OF_YEAR, value);
	return;
	}
	long fd = cachedFixedDate;
	// Make sure that the min week has the current DAY_OF_WEEK
	long day1 = fd - (7 * (woy - min));
	if (year != getMinimum(YEAR)) {
	if (gcal.getYearFromFixedDate(day1) != y) {
	min++;
	}
	} else {
	CalendarDate d = jcal.getCalendarDate(Long.MIN_VALUE, getZone());
	if (day1 < jcal.getFixedDate(d)) {
	min++;
	}
	}

	// Make sure the same thing for the max week
	fd += 7 * (max - internalGet(WEEK_OF_YEAR));
	if (gcal.getYearFromFixedDate(fd) != y) {
	max--;
	}
	break;
	}

	// Handle transition here.
	long fd = cachedFixedDate;
	long day1 = fd - (7 * (woy - min));
	// Make sure that the min week has the current DAY_OF_WEEK
	LocalGregorianCalendar.Date d = getCalendarDate(day1);
	if (!(d.getEra() == jdate.getEra() && d.getYear() == jdate.getYear())) {
	min++;
	}

	// Make sure the same thing for the max week
	fd += 7 * (max - woy);
	jcal.getCalendarDateFromFixedDate(d, fd);
	if (!(d.getEra() == jdate.getEra() && d.getYear() == jdate.getYear())) {
	max--;
	}
	// value: the new WEEK_OF_YEAR which must be converted
	// to month and day of month.
	value = getRolledValue(woy, amount, min, max) - 1;
	d = getCalendarDate(day1 + value * 7);
	set(MONTH, d.getMonth() - 1);
	set(DAY_OF_MONTH, d.getDayOfMonth());
	return;
	}

	case WEEK_OF_MONTH:
	{
	boolean isTransitionYear = isTransitionYear(jdate.getNormalizedYear());
	// dow: relative day of week from the first day of week
	int dow = internalGet(DAY_OF_WEEK) - getFirstDayOfWeek();
	if (dow < 0) {
	dow += 7;
	}

	long fd = cachedFixedDate;
	long month1; // fixed date of the first day (usually 1) of the month
	int monthLength; // actual month length
	if (isTransitionYear) {
	month1 = getFixedDateMonth1(jdate, fd);
	monthLength = actualMonthLength();
	} else {
	month1 = fd - internalGet(DAY_OF_MONTH) + 1;
	monthLength = jcal.getMonthLength(jdate);
	}

	// the first day of week of the month.
	long monthDay1st = LocalGregorianCalendar.getDayOfWeekDateOnOrBefore(month1 + 6,
	getFirstDayOfWeek());
	// if the week has enough days to form a week, the
	// week starts from the previous month.
	if ((int)(monthDay1st - month1) >= getMinimalDaysInFirstWeek()) {
	monthDay1st -= 7;
	}
	max = getActualMaximum(field);

	// value: the new WEEK_OF_MONTH value
	int value = getRolledValue(internalGet(field), amount, 1, max) - 1;

	// nfd: fixed date of the rolled date
	long nfd = monthDay1st + value * 7 + dow;

	// Unlike WEEK_OF_YEAR, we need to change day of week if the
	// nfd is out of the month.
	if (nfd < month1) {
	nfd = month1;
	} else if (nfd >= (month1 + monthLength)) {
	nfd = month1 + monthLength - 1;
	}
	set(DAY_OF_MONTH, getCalendarDate(nfd).getDayOfMonth());
	return;
	}

	case DAY_OF_MONTH:
	{
	if (!isTransitionYear(jdate.getNormalizedYear())) {
	max = jcal.getMonthLength(jdate);
	break;
	}

	// TODO: Need to change the spec to be usable DAY_OF_MONTH rolling...

	// Transition handling. We can't change year and era
	// values here due to the Calendar roll spec!
	long month1 = getFixedDateMonth1(jdate, cachedFixedDate);

	// It may not be a regular month. Convert the date and range to
	// the relative values, perform the roll, and
	// convert the result back to the rolled date.
	int value = getRolledValue((int)(cachedFixedDate - month1), amount,
	0, actualMonthLength() - 1);
	LocalGregorianCalendar.Date d = getCalendarDate(month1 + value);
	assert getEraIndex(d) == internalGetEra()
	&& d.getYear() == internalGet(YEAR) && d.getMonth()-1 == internalGet(MONTH);
	set(DAY_OF_MONTH, d.getDayOfMonth());
	return;
	}

	case DAY_OF_YEAR:
	{
	max = getActualMaximum(field);
	if (!isTransitionYear(jdate.getNormalizedYear())) {
	break;
	}

	// Handle transition. We can't change year and era values
	// here due to the Calendar roll spec.
	int value = getRolledValue(internalGet(DAY_OF_YEAR), amount, min, max);
	long jan0 = cachedFixedDate - internalGet(DAY_OF_YEAR);
	LocalGregorianCalendar.Date d = getCalendarDate(jan0 + value);
	assert getEraIndex(d) == internalGetEra() && d.getYear() == internalGet(YEAR);
	set(MONTH, d.getMonth() - 1);
	set(DAY_OF_MONTH, d.getDayOfMonth());
	return;
	}

	case DAY_OF_WEEK:
	{
	int normalizedYear = jdate.getNormalizedYear();
	if (!isTransitionYear(normalizedYear) && !isTransitionYear(normalizedYear - 1)) {
	// If the week of year is in the same year, we can
	// just change DAY_OF_WEEK.
	int weekOfYear = internalGet(WEEK_OF_YEAR);
	if (weekOfYear > 1 && weekOfYear < 52) {
	set(WEEK_OF_YEAR, internalGet(WEEK_OF_YEAR));
	max = SATURDAY;
	break;
	}
	}

	// We need to handle it in a different way around year
	// boundaries and in the transition year. Note that
	// changing era and year values violates the roll
	// rule: not changing larger calendar fields...
	amount %= 7;
	if (amount == 0) {
	return;
	}
	long fd = cachedFixedDate;
	long dowFirst = LocalGregorianCalendar.getDayOfWeekDateOnOrBefore(fd, getFirstDayOfWeek());
	fd += amount;
	if (fd < dowFirst) {
	fd += 7;
	} else if (fd >= dowFirst + 7) {
	fd -= 7;
	}
	LocalGregorianCalendar.Date d = getCalendarDate(fd);
	set(ERA, getEraIndex(d));
	set(d.getYear(), d.getMonth() - 1, d.getDayOfMonth());
	return;
	}

	case DAY_OF_WEEK_IN_MONTH:
	{
	min = 1; // after having normalized, min should be 1.
	if (!isTransitionYear(jdate.getNormalizedYear())) {
	int dom = internalGet(DAY_OF_MONTH);
	int monthLength = jcal.getMonthLength(jdate);
	int lastDays = monthLength % 7;
	max = monthLength / 7;
	int x = (dom - 1) % 7;
	if (x < lastDays) {
	max++;
	}
	set(DAY_OF_WEEK, internalGet(DAY_OF_WEEK));
	break;
	}

	// Transition year handling.
	long fd = cachedFixedDate;
	long month1 = getFixedDateMonth1(jdate, fd);
	int monthLength = actualMonthLength();
	int lastDays = monthLength % 7;
	max = monthLength / 7;
	int x = (int)(fd - month1) % 7;
	if (x < lastDays) {
	max++;
	}
	int value = getRolledValue(internalGet(field), amount, min, max) - 1;
	fd = month1 + value * 7 + x;
	LocalGregorianCalendar.Date d = getCalendarDate(fd);
	set(DAY_OF_MONTH, d.getDayOfMonth());
	return;
	}
	}

	set(field, getRolledValue(internalGet(field), amount, min, max));
	}

	@Override
	public String getDisplayName(int field, int style, Locale locale) {
	if (!checkDisplayNameParams(field, style, SHORT, NARROW_FORMAT, locale,
	ERA_MASK\|YEAR_MASK\|MONTH_MASK\|DAY_OF_WEEK_MASK\|AM_PM_MASK)) {
	return null;
	}

	int fieldValue = get(field);

	// "GanNen" is supported only in the LONG style.
	if (field == YEAR
	&& (getBaseStyle(style) != LONG \|\| fieldValue != 1 \|\| get(ERA) == 0)) {
	return null;
	}

	String name = CalendarDataUtility.retrieveFieldValueName(getCalendarType(), field,
	fieldValue, style, locale);
	// If the ERA value is null or empty, then
	// try to get its name or abbreviation from the Era instance.
	if ((name == null \|\| name.isEmpty()) &&
	field == ERA &&
	fieldValue < eras.length) {
	Era era = eras[fieldValue];
	name = (style == SHORT) ? era.getAbbreviation() : era.getName();
	}
	return name;
	}

	@Override
	public Map<String,Integer> getDisplayNames(int field, int style, Locale locale) {
	if (!checkDisplayNameParams(field, style, ALL_STYLES, NARROW_FORMAT, locale,
	ERA_MASK\|YEAR_MASK\|MONTH_MASK\|DAY_OF_WEEK_MASK\|AM_PM_MASK)) {
	return null;
	}
	Map<String, Integer> names;
	names = CalendarDataUtility.retrieveFieldValueNames(getCalendarType(), field, style, locale);
	// If strings[] has fewer than eras[], get more names from eras[].
	if (names != null) {
	if (field == ERA) {
	int size = names.size();
	if (style == ALL_STYLES) {
	Set<Integer> values = new HashSet<>();
	// count unique era values
	for (String key : names.keySet()) {
	values.add(names.get(key));
	}
	size = values.size();
	}
	if (size < eras.length) {
	int baseStyle = getBaseStyle(style);
	for (int i = 0; i < eras.length; i++) {
	if (!names.values().contains(i)) {
	Era era = eras[i];
	if (baseStyle == ALL_STYLES \|\| baseStyle == SHORT
	\|\| baseStyle == NARROW_FORMAT) {
	names.put(era.getAbbreviation(), i);
	}
	if (baseStyle == ALL_STYLES \|\| baseStyle == LONG) {
	names.put(era.getName(), i);
	}
	}
	}
	}
	}
	}
	return names;
	}

	/**
	* Returns the minimum value for the given calendar field of this
	* {@code Calendar} instance. The minimum value is
	* defined as the smallest value returned by the
	* {@link Calendar#get(int) get} method for any possible time value,
	* taking into consideration the current values of the
	* {@link Calendar#getFirstDayOfWeek() getFirstDayOfWeek},
	* {@link Calendar#getMinimalDaysInFirstWeek() getMinimalDaysInFirstWeek},
	* and {@link Calendar#getTimeZone() getTimeZone} methods.
	*
	* @param field the calendar field.
	* @return the minimum value for the given calendar field.
	* @see #getMaximum(int)
	* @see #getGreatestMinimum(int)
	* @see #getLeastMaximum(int)
	* @see #getActualMinimum(int)
	* @see #getActualMaximum(int)
	*/
	public int getMinimum(int field) {
	return MIN_VALUES[field];
	}

	/**
	* Returns the maximum value for the given calendar field of this
	* {@code GregorianCalendar} instance. The maximum value is
	* defined as the largest value returned by the
	* {@link Calendar#get(int) get} method for any possible time value,
	* taking into consideration the current values of the
	* {@link Calendar#getFirstDayOfWeek() getFirstDayOfWeek},
	* {@link Calendar#getMinimalDaysInFirstWeek() getMinimalDaysInFirstWeek},
	* and {@link Calendar#getTimeZone() getTimeZone} methods.
	*
	* @param field the calendar field.
	* @return the maximum value for the given calendar field.
	* @see #getMinimum(int)
	* @see #getGreatestMinimum(int)
	* @see #getLeastMaximum(int)
	* @see #getActualMinimum(int)
	* @see #getActualMaximum(int)
	*/
	public int getMaximum(int field) {
	return switch (field) {
	case YEAR -> {
	// The value should depend on the time zone of this calendar.
	LocalGregorianCalendar.Date d = jcal.getCalendarDate(Long.MAX_VALUE, getZone());
	yield Math.max(LEAST_MAX_VALUES[YEAR], d.getYear());
	}
	default -> MAX_VALUES[field];
	};
	}

	/**
	* Returns the highest minimum value for the given calendar field
	* of this {@code GregorianCalendar} instance. The highest
	* minimum value is defined as the largest value returned by
	* {@link #getActualMinimum(int)} for any possible time value,
	* taking into consideration the current values of the
	* {@link Calendar#getFirstDayOfWeek() getFirstDayOfWeek},
	* {@link Calendar#getMinimalDaysInFirstWeek() getMinimalDaysInFirstWeek},
	* and {@link Calendar#getTimeZone() getTimeZone} methods.
	*
	* @param field the calendar field.
	* @return the highest minimum value for the given calendar field.
	* @see #getMinimum(int)
	* @see #getMaximum(int)
	* @see #getLeastMaximum(int)
	* @see #getActualMinimum(int)
	* @see #getActualMaximum(int)
	*/
	public int getGreatestMinimum(int field) {
	return field == YEAR ? 1 : MIN_VALUES[field];
	}

	/**
	* Returns the lowest maximum value for the given calendar field
	* of this {@code GregorianCalendar} instance. The lowest
	* maximum value is defined as the smallest value returned by
	* {@link #getActualMaximum(int)} for any possible time value,
	* taking into consideration the current values of the
	* {@link Calendar#getFirstDayOfWeek() getFirstDayOfWeek},
	* {@link Calendar#getMinimalDaysInFirstWeek() getMinimalDaysInFirstWeek},
	* and {@link Calendar#getTimeZone() getTimeZone} methods.
	*
	* @param field the calendar field
	* @return the lowest maximum value for the given calendar field.
	* @see #getMinimum(int)
	* @see #getMaximum(int)
	* @see #getGreatestMinimum(int)
	* @see #getActualMinimum(int)
	* @see #getActualMaximum(int)
	*/
	public int getLeastMaximum(int field) {
	return switch (field) {
	case YEAR -> Math.min(LEAST_MAX_VALUES[YEAR], getMaximum(YEAR));
	default -> LEAST_MAX_VALUES[field];
	};
	}

	/**
	* Returns the minimum value that this calendar field could have,
	* taking into consideration the given time value and the current
	* values of the
	* {@link Calendar#getFirstDayOfWeek() getFirstDayOfWeek},
	* {@link Calendar#getMinimalDaysInFirstWeek() getMinimalDaysInFirstWeek},
	* and {@link Calendar#getTimeZone() getTimeZone} methods.
	*
	* @param field the calendar field
	* @return the minimum of the given field for the time value of
	* this {@code JapaneseImperialCalendar}
	* @see #getMinimum(int)
	* @see #getMaximum(int)
	* @see #getGreatestMinimum(int)
	* @see #getLeastMaximum(int)
	* @see #getActualMaximum(int)
	*/
	public int getActualMinimum(int field) {
	if (!isFieldSet(YEAR_MASK\|MONTH_MASK\|WEEK_OF_YEAR_MASK, field)) {
	return getMinimum(field);
	}

	int value = 0;
	JapaneseImperialCalendar jc = getNormalizedCalendar();
	// Get a local date which includes time of day and time zone,
	// which are missing in jc.jdate.
	LocalGregorianCalendar.Date jd = jcal.getCalendarDate(jc.getTimeInMillis(),
	getZone());
	int eraIndex = getEraIndex(jd);
	switch (field) {
	case YEAR -> {
	if (eraIndex > BEFORE_MEIJI) {
	value = 1;
	long since = eras[eraIndex].getSince(getZone());
	CalendarDate d = jcal.getCalendarDate(since, getZone());
	// Use the same year in jd to take care of leap
	// years. i.e., both jd and d must agree on leap
	// or common years.
	jd.setYear(d.getYear());
	jcal.normalize(jd);
	assert jd.isLeapYear() == d.isLeapYear();
	if (getYearOffsetInMillis(jd) < getYearOffsetInMillis(d)) {
	value++;
	}
	} else {
	value = getMinimum(field);
	CalendarDate d = jcal.getCalendarDate(Long.MIN_VALUE, getZone());
	// Use an equvalent year of d.getYear() if
	// possible. Otherwise, ignore the leap year and
	// common year difference.
	int y = d.getYear();
	if (y > 400) {
	y -= 400;
	}
	jd.setYear(y);
	jcal.normalize(jd);
	if (getYearOffsetInMillis(jd) < getYearOffsetInMillis(d)) {
	value++;
	}
	}
	}
	case MONTH -> {
	// In Before Meiji and Meiji, January is the first month.
	if (eraIndex > MEIJI && jd.getYear() == 1) {
	long since = eras[eraIndex].getSince(getZone());
	CalendarDate d = jcal.getCalendarDate(since, getZone());
	value = d.getMonth() - 1;
	if (jd.getDayOfMonth() < d.getDayOfMonth()) {
	value++;
	}
	}
	}
	case WEEK_OF_YEAR -> {
	value = 1;
	CalendarDate d = jcal.getCalendarDate(Long.MIN_VALUE, getZone());
	// shift 400 years to avoid underflow
	d.addYear(+400);
	jcal.normalize(d);
	jd.setEra(d.getEra());
	jd.setYear(d.getYear());
	jcal.normalize(jd);

	long jan1 = jcal.getFixedDate(d);
	long fd = jcal.getFixedDate(jd);
	int woy = getWeekNumber(jan1, fd);
	long day1 = fd - (7 * (woy - 1));
	if ((day1 < jan1) \|\|
	(day1 == jan1 &&
	jd.getTimeOfDay() < d.getTimeOfDay())) {
	value++;
	}
	}
	}
	return value;
	}

	/**
	* Returns the maximum value that this calendar field could have,
	* taking into consideration the given time value and the current
	* values of the
	* {@link Calendar#getFirstDayOfWeek() getFirstDayOfWeek},
	* {@link Calendar#getMinimalDaysInFirstWeek() getMinimalDaysInFirstWeek},
	* and
	* {@link Calendar#getTimeZone() getTimeZone} methods.
	* For example, if the date of this instance is Heisei 16February 1,
	* the actual maximum value of the {@code DAY_OF_MONTH} field
	* is 29 because Heisei 16 is a leap year, and if the date of this
	* instance is Heisei 17 February 1, it's 28.
	*
	* @param field the calendar field
	* @return the maximum of the given field for the time value of
	* this {@code JapaneseImperialCalendar}
	* @see #getMinimum(int)
	* @see #getMaximum(int)
	* @see #getGreatestMinimum(int)
	* @see #getLeastMaximum(int)
	* @see #getActualMinimum(int)
	*/
	public int getActualMaximum(int field) {
	final int fieldsForFixedMax = ERA_MASK\|DAY_OF_WEEK_MASK\|HOUR_MASK\|AM_PM_MASK\|
	HOUR_OF_DAY_MASK\|MINUTE_MASK\|SECOND_MASK\|MILLISECOND_MASK\|
	ZONE_OFFSET_MASK\|DST_OFFSET_MASK;
	if ((fieldsForFixedMax & (1<<field)) != 0) {
	return getMaximum(field);
	}

	JapaneseImperialCalendar jc = getNormalizedCalendar();
	LocalGregorianCalendar.Date date = jc.jdate;

	return switch (field) {
	case MONTH -> {
	int month = DECEMBER;
	if (isTransitionYear(date.getNormalizedYear())) {
	// TODO: there may be multiple transitions in a year.
	int eraIndex = getEraIndex(date);
	if (date.getYear() != 1) {
	eraIndex++;
	assert eraIndex < eras.length;
	}
	long transition = sinceFixedDates[eraIndex];
	long fd = jc.cachedFixedDate;
	if (fd < transition) {
	LocalGregorianCalendar.Date ldate
	= (LocalGregorianCalendar.Date) date.clone();
	jcal.getCalendarDateFromFixedDate(ldate, transition - 1);
	month = ldate.getMonth() - 1;
	}
	} else {
	LocalGregorianCalendar.Date d = jcal.getCalendarDate(Long.MAX_VALUE, getZone());
	if (date.getEra() == d.getEra() && date.getYear() == d.getYear()) {
	month = d.getMonth() - 1;
	}
	}
	yield month;
	}
	case DAY_OF_MONTH -> jcal.getMonthLength(date);
	case DAY_OF_YEAR -> {
	if (isTransitionYear(date.getNormalizedYear())) {
	// Handle transition year.
	// TODO: there may be multiple transitions in a year.
	int eraIndex = getEraIndex(date);
	if (date.getYear() != 1) {
	eraIndex++;
	assert eraIndex < eras.length;
	}
	long transition = sinceFixedDates[eraIndex];
	long fd = jc.cachedFixedDate;
	CalendarDate d = gcal.newCalendarDate(TimeZone.NO_TIMEZONE);
	d.setDate(date.getNormalizedYear(), BaseCalendar.JANUARY, 1);
	if (fd < transition) {
	yield (int) (transition - gcal.getFixedDate(d));
	}
	d.addYear(1);
	yield (int) (gcal.getFixedDate(d) - transition);
	}
	LocalGregorianCalendar.Date d = jcal.getCalendarDate(Long.MAX_VALUE, getZone());
	if (date.getEra() == d.getEra() && date.getYear() == d.getYear()) {
	long fd = jcal.getFixedDate(d);
	long jan1 = getFixedDateJan1(d, fd);
	yield (int) (fd - jan1) + 1;
	} else if (date.getYear() == getMinimum(YEAR)) {
	CalendarDate d1 = jcal.getCalendarDate(Long.MIN_VALUE, getZone());
	long fd1 = jcal.getFixedDate(d1);
	d1.addYear(1);
	d1.setMonth(BaseCalendar.JANUARY).setDayOfMonth(1);
	jcal.normalize(d1);
	long fd2 = jcal.getFixedDate(d1);
	yield (int) (fd2 - fd1);
	} else {
	yield jcal.getYearLength(date);
	}
	}
	case WEEK_OF_YEAR -> {
	if (!isTransitionYear(date.getNormalizedYear())) {
	LocalGregorianCalendar.Date jd = jcal.getCalendarDate(Long.MAX_VALUE, getZone());
	if (date.getEra() == jd.getEra() && date.getYear() == jd.getYear()) {
	long fd = jcal.getFixedDate(jd);
	long jan1 = getFixedDateJan1(jd, fd);
	yield getWeekNumber(jan1, fd);
	} else if (date.getEra() == null && date.getYear() == getMinimum(YEAR)) {
	CalendarDate d = jcal.getCalendarDate(Long.MIN_VALUE, getZone());
	// shift 400 years to avoid underflow
	d.addYear(+400);
	jcal.normalize(d);
	jd.setEra(d.getEra());
	jd.setDate(d.getYear() + 1, BaseCalendar.JANUARY, 1);
	jcal.normalize(jd);
	long jan1 = jcal.getFixedDate(d);
	long nextJan1 = jcal.getFixedDate(jd);
	long nextJan1st = LocalGregorianCalendar.getDayOfWeekDateOnOrBefore(nextJan1 + 6,
	getFirstDayOfWeek());
	int ndays = (int) (nextJan1st - nextJan1);
	if (ndays >= getMinimalDaysInFirstWeek()) {
	nextJan1st -= 7;
	}
	yield getWeekNumber(jan1, nextJan1st);
	}
	// Get the day of week of January 1 of the year
	CalendarDate d = gcal.newCalendarDate(TimeZone.NO_TIMEZONE);
	d.setDate(date.getNormalizedYear(), BaseCalendar.JANUARY, 1);
	int dayOfWeek = gcal.getDayOfWeek(d);
	// Normalize the day of week with the firstDayOfWeek value
	dayOfWeek -= getFirstDayOfWeek();
	if (dayOfWeek < 0) {
	dayOfWeek += 7;
	}
	int magic = dayOfWeek + getMinimalDaysInFirstWeek() - 1;
	if ((magic == 6) \|\|
	(date.isLeapYear() && (magic == 5 \|\| magic == 12))) {
	yield 53;
	}
	yield 52;
	}

	if (jc == this) {
	jc = (JapaneseImperialCalendar) jc.clone();
	}
	int max = getActualMaximum(DAY_OF_YEAR);
	jc.set(DAY_OF_YEAR, max);
	int weekOfYear = jc.get(WEEK_OF_YEAR);
	if (weekOfYear == 1 && max > 7) {
	jc.add(WEEK_OF_YEAR, -1);
	weekOfYear = jc.get(WEEK_OF_YEAR);
	}
	yield weekOfYear;
	}
	case WEEK_OF_MONTH -> {
	LocalGregorianCalendar.Date jd = jcal.getCalendarDate(Long.MAX_VALUE, getZone());
	if (date.getEra() == jd.getEra() && date.getYear() == jd.getYear()) {
	long fd = jcal.getFixedDate(jd);
	long month1 = fd - jd.getDayOfMonth() + 1;
	yield getWeekNumber(month1, fd);
	}
	CalendarDate d = gcal.newCalendarDate(TimeZone.NO_TIMEZONE);
	d.setDate(date.getNormalizedYear(), date.getMonth(), 1);
	int dayOfWeek = gcal.getDayOfWeek(d);
	int monthLength = actualMonthLength();
	dayOfWeek -= getFirstDayOfWeek();
	if (dayOfWeek < 0) {
	dayOfWeek += 7;
	}
	int nDaysFirstWeek = 7 - dayOfWeek; // # of days in the first week
	int weekOfMonth = 3;
	if (nDaysFirstWeek >= getMinimalDaysInFirstWeek()) {
	weekOfMonth++;
	}
	monthLength -= nDaysFirstWeek + 7 * 3;
	if (monthLength > 0) {
	weekOfMonth++;
	if (monthLength > 7) {
	weekOfMonth++;
	}
	}
	yield weekOfMonth;
	}
	case DAY_OF_WEEK_IN_MONTH -> {
	int ndays, dow1;
	int dow = date.getDayOfWeek();
	BaseCalendar.Date d = (BaseCalendar.Date) date.clone();
	ndays = jcal.getMonthLength(d);
	d.setDayOfMonth(1);
	jcal.normalize(d);
	dow1 = d.getDayOfWeek();
	int x = dow - dow1;
	if (x < 0) {
	x += 7;
	}
	ndays -= x;
	yield (ndays + 6) / 7;
	}
	case YEAR -> {
	CalendarDate jd = jcal.getCalendarDate(jc.getTimeInMillis(), getZone());
	CalendarDate d;
	int eraIndex = getEraIndex(date);
	int year;
	if (eraIndex == eras.length - 1) {
	d = jcal.getCalendarDate(Long.MAX_VALUE, getZone());
	year = d.getYear();
	// Use an equivalent year for the
	// getYearOffsetInMillis call to avoid overflow.
	if (year > 400) {
	jd.setYear(year - 400);
	}
	} else {
	d = jcal.getCalendarDate(eras[eraIndex + 1].getSince(getZone()) - 1, getZone());
	year = d.getYear();
	// Use the same year as d.getYear() to be
	// consistent with leap and common years.
	jd.setYear(year);
	}
	jcal.normalize(jd);
	if (getYearOffsetInMillis(jd) > getYearOffsetInMillis(d)) {
	year--;
	}
	yield year;
	}
	default -> throw new ArrayIndexOutOfBoundsException(field);
	};
	}

	/**
	* Returns the millisecond offset from the beginning of the
	* year. In the year for Long.MIN_VALUE, it's a pseudo value
	* beyond the limit. The given CalendarDate object must have been
	* normalized before calling this method.
	*/
	private long getYearOffsetInMillis(CalendarDate date) {
	long t = (jcal.getDayOfYear(date) - 1) * ONE_DAY;
	return t + date.getTimeOfDay() - date.getZoneOffset();
	}

	public Object clone() {
	JapaneseImperialCalendar other = (JapaneseImperialCalendar) super.clone();

	other.jdate = (LocalGregorianCalendar.Date) jdate.clone();
	other.originalFields = null;
	other.zoneOffsets = null;
	return other;
	}

	public TimeZone getTimeZone() {
	TimeZone zone = super.getTimeZone();
	// To share the zone by the CalendarDate
	jdate.setZone(zone);
	return zone;
	}

	public void setTimeZone(TimeZone zone) {
	super.setTimeZone(zone);
	// To share the zone by the CalendarDate
	jdate.setZone(zone);
	}

	/**
	* The fixed date corresponding to jdate. If the value is
	* Long.MIN_VALUE, the fixed date value is unknown.
	*/
	private transient long cachedFixedDate = Long.MIN_VALUE;

	/**
	* Converts the time value (millisecond offset from the <a
	* href="Calendar.html#Epoch">Epoch</a>) to calendar field values.
	* The time is <em>not</em>
	* recomputed first; to recompute the time, then the fields, call the
	* {@code complete} method.
	*
	* @see Calendar#complete
	*/
	protected void computeFields() {
	int mask = 0;
	if (isPartiallyNormalized()) {
	// Determine which calendar fields need to be computed.
	mask = getSetStateFields();
	int fieldMask = ~mask & ALL_FIELDS;
	if (fieldMask != 0 \|\| cachedFixedDate == Long.MIN_VALUE) {
	mask \|= computeFields(fieldMask,
	mask & (ZONE_OFFSET_MASK\|DST_OFFSET_MASK));
	assert mask == ALL_FIELDS;
	}
	} else {
	// Specify all fields
	mask = ALL_FIELDS;
	computeFields(mask, 0);
	}
	// After computing all the fields, set the field state to `COMPUTED'.
	setFieldsComputed(mask);
	}

	/**
	* This computeFields implements the conversion from UTC
	* (millisecond offset from the Epoch) to calendar
	* field values. fieldMask specifies which fields to change the
	* setting state to COMPUTED, although all fields are set to
	* the correct values. This is required to fix 4685354.
	*
	* @param fieldMask a bit mask to specify which fields to change
	* the setting state.
	* @param tzMask a bit mask to specify which time zone offset
	* fields to be used for time calculations
	* @return a new field mask that indicates what field values have
	* actually been set.
	*/
	private int computeFields(int fieldMask, int tzMask) {
	int zoneOffset = 0;
	TimeZone tz = getZone();
	if (zoneOffsets == null) {
	zoneOffsets = new int[2];
	}
	if (tzMask != (ZONE_OFFSET_MASK\|DST_OFFSET_MASK)) {
	if (tz instanceof ZoneInfo) {
	zoneOffset = ((ZoneInfo)tz).getOffsets(time, zoneOffsets);
	} else {
	zoneOffset = tz.getOffset(time);
	zoneOffsets[0] = tz.getRawOffset();
	zoneOffsets[1] = zoneOffset - zoneOffsets[0];
	}
	}
	if (tzMask != 0) {
	if (isFieldSet(tzMask, ZONE_OFFSET)) {
	zoneOffsets[0] = internalGet(ZONE_OFFSET);
	}
	if (isFieldSet(tzMask, DST_OFFSET)) {
	zoneOffsets[1] = internalGet(DST_OFFSET);
	}
	zoneOffset = zoneOffsets[0] + zoneOffsets[1];
	}

	// By computing time and zoneOffset separately, we can take
	// the wider range of time+zoneOffset than the previous
	// implementation.
	long fixedDate = zoneOffset / ONE_DAY;
	int timeOfDay = zoneOffset % (int)ONE_DAY;
	fixedDate += time / ONE_DAY;
	timeOfDay += (int) (time % ONE_DAY);
	if (timeOfDay >= ONE_DAY) {
	timeOfDay -= ONE_DAY;
	++fixedDate;
	} else {
	while (timeOfDay < 0) {
	timeOfDay += ONE_DAY;
	--fixedDate;
	}
	}
	fixedDate += EPOCH_OFFSET;

	// See if we can use jdate to avoid date calculation.
	if (fixedDate != cachedFixedDate \|\| fixedDate < 0) {
	jcal.getCalendarDateFromFixedDate(jdate, fixedDate);
	cachedFixedDate = fixedDate;
	}
	int era = getEraIndex(jdate);
	int year = jdate.getYear();

	// Always set the ERA and YEAR values.
	internalSet(ERA, era);
	internalSet(YEAR, year);
	int mask = fieldMask \| (ERA_MASK\|YEAR_MASK);

	int month = jdate.getMonth() - 1; // 0-based
	int dayOfMonth = jdate.getDayOfMonth();

	// Set the basic date fields.
	if ((fieldMask & (MONTH_MASK\|DAY_OF_MONTH_MASK\|DAY_OF_WEEK_MASK))
	!= 0) {
	internalSet(MONTH, month);
	internalSet(DAY_OF_MONTH, dayOfMonth);
	internalSet(DAY_OF_WEEK, jdate.getDayOfWeek());
	mask \|= MONTH_MASK\|DAY_OF_MONTH_MASK\|DAY_OF_WEEK_MASK;
	}

	if ((fieldMask & (HOUR_OF_DAY_MASK\|AM_PM_MASK\|HOUR_MASK
	\|MINUTE_MASK\|SECOND_MASK\|MILLISECOND_MASK)) != 0) {
	if (timeOfDay != 0) {
	int hours = timeOfDay / ONE_HOUR;
	internalSet(HOUR_OF_DAY, hours);
	internalSet(AM_PM, hours / 12); // Assume AM == 0
	internalSet(HOUR, hours % 12);
	int r = timeOfDay % ONE_HOUR;
	internalSet(MINUTE, r / ONE_MINUTE);
	r %= ONE_MINUTE;
	internalSet(SECOND, r / ONE_SECOND);
	internalSet(MILLISECOND, r % ONE_SECOND);
	} else {
	internalSet(HOUR_OF_DAY, 0);
	internalSet(AM_PM, AM);
	internalSet(HOUR, 0);
	internalSet(MINUTE, 0);
	internalSet(SECOND, 0);
	internalSet(MILLISECOND, 0);
	}
	mask \|= (HOUR_OF_DAY_MASK\|AM_PM_MASK\|HOUR_MASK
	\|MINUTE_MASK\|SECOND_MASK\|MILLISECOND_MASK);
	}

	if ((fieldMask & (ZONE_OFFSET_MASK\|DST_OFFSET_MASK)) != 0) {
	internalSet(ZONE_OFFSET, zoneOffsets[0]);
	internalSet(DST_OFFSET, zoneOffsets[1]);
	mask \|= (ZONE_OFFSET_MASK\|DST_OFFSET_MASK);
	}

	if ((fieldMask & (DAY_OF_YEAR_MASK\|WEEK_OF_YEAR_MASK
	\|WEEK_OF_MONTH_MASK\|DAY_OF_WEEK_IN_MONTH_MASK)) != 0) {
	int normalizedYear = jdate.getNormalizedYear();
	// If it's a year of an era transition, we need to handle
	// irregular year boundaries.
	boolean transitionYear = isTransitionYear(jdate.getNormalizedYear());
	int dayOfYear;
	long fixedDateJan1;
	if (transitionYear) {
	fixedDateJan1 = getFixedDateJan1(jdate, fixedDate);
	dayOfYear = (int)(fixedDate - fixedDateJan1) + 1;
	} else if (normalizedYear == MIN_VALUES[YEAR]) {
	CalendarDate dx = jcal.getCalendarDate(Long.MIN_VALUE, getZone());
	fixedDateJan1 = jcal.getFixedDate(dx);
	dayOfYear = (int)(fixedDate - fixedDateJan1) + 1;
	} else {
	dayOfYear = (int) jcal.getDayOfYear(jdate);
	fixedDateJan1 = fixedDate - dayOfYear + 1;
	}
	long fixedDateMonth1 = transitionYear ?
	getFixedDateMonth1(jdate, fixedDate) : fixedDate - dayOfMonth + 1;

	internalSet(DAY_OF_YEAR, dayOfYear);
	internalSet(DAY_OF_WEEK_IN_MONTH, (dayOfMonth - 1) / 7 + 1);

	int weekOfYear = getWeekNumber(fixedDateJan1, fixedDate);

	// The spec is to calculate WEEK_OF_YEAR in the
	// ISO8601-style. This creates problems, though.
	if (weekOfYear == 0) {
	// If the date belongs to the last week of the
	// previous year, use the week number of "12/31" of
	// the "previous" year. Again, if the previous year is
	// a transition year, we need to take care of it.
	// Usually the previous day of the first day of a year
	// is December 31, which is not always true in the
	// Japanese imperial calendar system.
	long fixedDec31 = fixedDateJan1 - 1;
	long prevJan1;
	LocalGregorianCalendar.Date d = getCalendarDate(fixedDec31);
	if (!(transitionYear \|\| isTransitionYear(d.getNormalizedYear()))) {
	prevJan1 = fixedDateJan1 - 365;
	if (d.isLeapYear()) {
	--prevJan1;
	}
	} else if (transitionYear) {
	if (jdate.getYear() == 1) {
	// As of Reiwa (since Meiji) there's no case
	// that there are multiple transitions in a
	// year. Historically there was such
	// case. There might be such case again in the
	// future.
	if (era > REIWA) {
	CalendarDate pd = eras[era - 1].getSinceDate();
	if (normalizedYear == pd.getYear()) {
	d.setMonth(pd.getMonth()).setDayOfMonth(pd.getDayOfMonth());
	}
	} else {
	d.setMonth(LocalGregorianCalendar.JANUARY).setDayOfMonth(1);
	}
	jcal.normalize(d);
	prevJan1 = jcal.getFixedDate(d);
	} else {
	prevJan1 = fixedDateJan1 - 365;
	if (d.isLeapYear()) {
	--prevJan1;
	}
	}
	} else {
	CalendarDate cd = eras[getEraIndex(jdate)].getSinceDate();
	d.setMonth(cd.getMonth()).setDayOfMonth(cd.getDayOfMonth());
	jcal.normalize(d);
	prevJan1 = jcal.getFixedDate(d);
	}
	weekOfYear = getWeekNumber(prevJan1, fixedDec31);
	} else {
	if (!transitionYear) {
	// Regular years
	if (weekOfYear >= 52) {
	long nextJan1 = fixedDateJan1 + 365;
	if (jdate.isLeapYear()) {
	nextJan1++;
	}
	long nextJan1st = LocalGregorianCalendar.getDayOfWeekDateOnOrBefore(nextJan1 + 6,
	getFirstDayOfWeek());
	int ndays = (int)(nextJan1st - nextJan1);
	if (ndays >= getMinimalDaysInFirstWeek() && fixedDate >= (nextJan1st - 7)) {
	// The first days forms a week in which the date is included.
	weekOfYear = 1;
	}
	}
	} else {
	LocalGregorianCalendar.Date d = (LocalGregorianCalendar.Date) jdate.clone();
	long nextJan1;
	if (jdate.getYear() == 1) {
	d.addYear(+1);
	d.setMonth(LocalGregorianCalendar.JANUARY).setDayOfMonth(1);
	nextJan1 = jcal.getFixedDate(d);
	} else {
	int nextEraIndex = getEraIndex(d) + 1;
	CalendarDate cd = eras[nextEraIndex].getSinceDate();
	d.setEra(eras[nextEraIndex]);
	d.setDate(1, cd.getMonth(), cd.getDayOfMonth());
	jcal.normalize(d);
	nextJan1 = jcal.getFixedDate(d);
	}
	long nextJan1st = LocalGregorianCalendar.getDayOfWeekDateOnOrBefore(nextJan1 + 6,
	getFirstDayOfWeek());
	int ndays = (int)(nextJan1st - nextJan1);
	if (ndays >= getMinimalDaysInFirstWeek() && fixedDate >= (nextJan1st - 7)) {
	// The first days forms a week in which the date is included.
	weekOfYear = 1;
	}
	}
	}
	internalSet(WEEK_OF_YEAR, weekOfYear);
	internalSet(WEEK_OF_MONTH, getWeekNumber(fixedDateMonth1, fixedDate));
	mask \|= (DAY_OF_YEAR_MASK\|WEEK_OF_YEAR_MASK\|WEEK_OF_MONTH_MASK\|DAY_OF_WEEK_IN_MONTH_MASK);
	}
	return mask;
	}

	/**
	* Returns the number of weeks in a period between fixedDay1 and
	* fixedDate. The getFirstDayOfWeek-getMinimalDaysInFirstWeek rule
	* is applied to calculate the number of weeks.
	*
	* @param fixedDay1 the fixed date of the first day of the period
	* @param fixedDate the fixed date of the last day of the period
	* @return the number of weeks of the given period
	*/
	private int getWeekNumber(long fixedDay1, long fixedDate) {
	// We can always use `jcal' since Julian and Gregorian are the
	// same thing for this calculation.
	long fixedDay1st = LocalGregorianCalendar.getDayOfWeekDateOnOrBefore(fixedDay1 + 6,
	getFirstDayOfWeek());
	int ndays = (int)(fixedDay1st - fixedDay1);
	assert ndays <= 7;
	if (ndays >= getMinimalDaysInFirstWeek()) {
	fixedDay1st -= 7;
	}
	int normalizedDayOfPeriod = (int)(fixedDate - fixedDay1st);
	if (normalizedDayOfPeriod >= 0) {
	return normalizedDayOfPeriod / 7 + 1;
	}
	return CalendarUtils.floorDivide(normalizedDayOfPeriod, 7) + 1;
	}

	/**
	* Converts calendar field values to the time value (millisecond
	* offset from the <a href="Calendar.html#Epoch">Epoch</a>).
	*
	* @throws IllegalArgumentException if any calendar fields are invalid.
	*/
	protected void computeTime() {
	// In non-lenient mode, perform brief checking of calendar
	// fields which have been set externally. Through this
	// checking, the field values are stored in originalFields[]
	// to see if any of them are normalized later.
	if (!isLenient()) {
	if (originalFields == null) {
	originalFields = new int[FIELD_COUNT];
	}
	for (int field = 0; field < FIELD_COUNT; field++) {
	int value = internalGet(field);
	if (isExternallySet(field)) {
	// Quick validation for any out of range values
	if (value < getMinimum(field) \|\| value > getMaximum(field)) {
	throw new IllegalArgumentException(getFieldName(field));
	}
	}
	originalFields[field] = value;
	}
	}

	// Let the super class determine which calendar fields to be
	// used to calculate the time.
	int fieldMask = selectFields();

	int year;
	int era;

	if (isSet(ERA)) {
	era = internalGet(ERA);
	year = isSet(YEAR) ? internalGet(YEAR) : 1;
	} else {
	if (isSet(YEAR)) {
	era = currentEra;
	year = internalGet(YEAR);
	} else {
	// Equivalent to 1970 (Gregorian)
	era = SHOWA;
	year = 45;
	}
	}

	// Calculate the time of day. We rely on the convention that
	// an UNSET field has 0.
	long timeOfDay = 0;
	if (isFieldSet(fieldMask, HOUR_OF_DAY)) {
	timeOfDay += (long) internalGet(HOUR_OF_DAY);
	} else {
	timeOfDay += internalGet(HOUR);
	// The default value of AM_PM is 0 which designates AM.
	if (isFieldSet(fieldMask, AM_PM)) {
	timeOfDay += 12 * internalGet(AM_PM);
	}
	}
	timeOfDay *= 60;
	timeOfDay += internalGet(MINUTE);
	timeOfDay *= 60;
	timeOfDay += internalGet(SECOND);
	timeOfDay *= 1000;
	timeOfDay += internalGet(MILLISECOND);

	// Convert the time of day to the number of days and the
	// millisecond offset from midnight.
	long fixedDate = timeOfDay / ONE_DAY;
	timeOfDay %= ONE_DAY;
	while (timeOfDay < 0) {
	timeOfDay += ONE_DAY;
	--fixedDate;
	}

	// Calculate the fixed date since January 1, 1 (Gregorian).
	fixedDate += getFixedDate(era, year, fieldMask);

	// millis represents local wall-clock time in milliseconds.
	long millis = (fixedDate - EPOCH_OFFSET) * ONE_DAY + timeOfDay;

	// Compute the time zone offset and DST offset. There are two potential
	// ambiguities here. We'll assume a 2:00 am (wall time) switchover time
	// for discussion purposes here.
	// 1. The transition into DST. Here, a designated time of 2:00 am - 2:59 am
	// can be in standard or in DST depending. However, 2:00 am is an invalid
	// representation (the representation jumps from 1:59:59 am Std to 3:00:00 am DST).
	// We assume standard time.
	// 2. The transition out of DST. Here, a designated time of 1:00 am - 1:59 am
	// can be in standard or DST. Both are valid representations (the rep
	// jumps from 1:59:59 DST to 1:00:00 Std).
	// Again, we assume standard time.
	// We use the TimeZone object, unless the user has explicitly set the ZONE_OFFSET
	// or DST_OFFSET fields; then we use those fields.
	TimeZone zone = getZone();
	if (zoneOffsets == null) {
	zoneOffsets = new int[2];
	}
	int tzMask = fieldMask & (ZONE_OFFSET_MASK\|DST_OFFSET_MASK);
	if (tzMask != (ZONE_OFFSET_MASK\|DST_OFFSET_MASK)) {
	if (zone instanceof ZoneInfo) {
	((ZoneInfo)zone).getOffsetsByWall(millis, zoneOffsets);
	} else {
	zone.getOffsets(millis - zone.getRawOffset(), zoneOffsets);
	}
	}
	if (tzMask != 0) {
	if (isFieldSet(tzMask, ZONE_OFFSET)) {
	zoneOffsets[0] = internalGet(ZONE_OFFSET);
	}
	if (isFieldSet(tzMask, DST_OFFSET)) {
	zoneOffsets[1] = internalGet(DST_OFFSET);
	}
	}

	// Adjust the time zone offset values to get the UTC time.
	millis -= zoneOffsets[0] + zoneOffsets[1];

	// Set this calendar's time in milliseconds
	time = millis;

	int mask = computeFields(fieldMask \| getSetStateFields(), tzMask);

	if (!isLenient()) {
	for (int field = 0; field < FIELD_COUNT; field++) {
	if (!isExternallySet(field)) {
	continue;
	}
	if (originalFields[field] != internalGet(field)) {
	int wrongValue = internalGet(field);
	// Restore the original field values
	System.arraycopy(originalFields, 0, fields, 0, fields.length);
	throw new IllegalArgumentException(getFieldName(field) + "=" + wrongValue
	+ ", expected " + originalFields[field]);
	}
	}
	}
	setFieldsNormalized(mask);
	}

	/**
	* Computes the fixed date under either the Gregorian or the
	* Julian calendar, using the given year and the specified calendar fields.
	*
	* @param era era index
	* @param year the normalized year number, with 0 indicating the
	* year 1 BCE, -1 indicating 2 BCE, etc.
	* @param fieldMask the calendar fields to be used for the date calculation
	* @return the fixed date
	* @see Calendar#selectFields
	*/
	private long getFixedDate(int era, int year, int fieldMask) {
	int month = JANUARY;
	int firstDayOfMonth = 1;
	if (isFieldSet(fieldMask, MONTH)) {
	// No need to check if MONTH has been set (no isSet(MONTH)
	// call) since its unset value happens to be JANUARY (0).
	month = internalGet(MONTH);

	// If the month is out of range, adjust it into range.
	if (month > DECEMBER) {
	year += month / 12;
	month %= 12;
	} else if (month < JANUARY) {
	int[] rem = new int[1];
	year += CalendarUtils.floorDivide(month, 12, rem);
	month = rem[0];
	}
	} else {
	if (year == 1 && era != 0) {
	CalendarDate d = eras[era].getSinceDate();
	month = d.getMonth() - 1;
	firstDayOfMonth = d.getDayOfMonth();
	}
	}

	// Adjust the base date if year is the minimum value.
	if (year == MIN_VALUES[YEAR]) {
	CalendarDate dx = jcal.getCalendarDate(Long.MIN_VALUE, getZone());
	int m = dx.getMonth() - 1;
	if (month < m) {
	month = m;
	}
	if (month == m) {
	firstDayOfMonth = dx.getDayOfMonth();
	}
	}

	LocalGregorianCalendar.Date date = jcal.newCalendarDate(TimeZone.NO_TIMEZONE);
	date.setEra(era > 0 ? eras[era] : null);
	date.setDate(year, month + 1, firstDayOfMonth);
	jcal.normalize(date);

	// Get the fixed date since Jan 1, 1 (Gregorian). We are on
	// the first day of either `month' or January in 'year'.
	long fixedDate = jcal.getFixedDate(date);

	if (isFieldSet(fieldMask, MONTH)) {
	// Month-based calculations
	if (isFieldSet(fieldMask, DAY_OF_MONTH)) {
	// We are on the "first day" of the month (which may
	// not be 1). Just add the offset if DAY_OF_MONTH is
	// set. If the isSet call returns false, that means
	// DAY_OF_MONTH has been selected just because of the
	// selected combination. We don't need to add any
	// since the default value is the "first day".
	if (isSet(DAY_OF_MONTH)) {
	// To avoid underflow with DAY_OF_MONTH-firstDayOfMonth, add
	// DAY_OF_MONTH, then subtract firstDayOfMonth.
	fixedDate += internalGet(DAY_OF_MONTH);
	fixedDate -= firstDayOfMonth;
	}
	} else {
	if (isFieldSet(fieldMask, WEEK_OF_MONTH)) {
	long firstDayOfWeek = LocalGregorianCalendar.getDayOfWeekDateOnOrBefore(fixedDate + 6,
	getFirstDayOfWeek());
	// If we have enough days in the first week, then
	// move to the previous week.
	if ((firstDayOfWeek - fixedDate) >= getMinimalDaysInFirstWeek()) {
	firstDayOfWeek -= 7;
	}
	if (isFieldSet(fieldMask, DAY_OF_WEEK)) {
	firstDayOfWeek = LocalGregorianCalendar.getDayOfWeekDateOnOrBefore(firstDayOfWeek + 6,
	internalGet(DAY_OF_WEEK));
	}
	// In lenient mode, we treat days of the previous
	// months as a part of the specified
	// WEEK_OF_MONTH. See 4633646.
	fixedDate = firstDayOfWeek + 7 * (internalGet(WEEK_OF_MONTH) - 1);
	} else {
	int dayOfWeek;
	if (isFieldSet(fieldMask, DAY_OF_WEEK)) {
	dayOfWeek = internalGet(DAY_OF_WEEK);
	} else {
	dayOfWeek = getFirstDayOfWeek();
	}
	// We are basing this on the day-of-week-in-month. The only
	// trickiness occurs if the day-of-week-in-month is
	// negative.
	int dowim;
	if (isFieldSet(fieldMask, DAY_OF_WEEK_IN_MONTH)) {
	dowim = internalGet(DAY_OF_WEEK_IN_MONTH);
	} else {
	dowim = 1;
	}
	if (dowim >= 0) {
	fixedDate = LocalGregorianCalendar.getDayOfWeekDateOnOrBefore(fixedDate + (7 * dowim) - 1,
	dayOfWeek);
	} else {
	// Go to the first day of the next week of
	// the specified week boundary.
	int lastDate = monthLength(month, year) + (7 * (dowim + 1));
	// Then, get the day of week date on or before the last date.
	fixedDate = LocalGregorianCalendar.getDayOfWeekDateOnOrBefore(fixedDate + lastDate - 1,
	dayOfWeek);
	}
	}
	}
	} else {
	// We are on the first day of the year.
	if (isFieldSet(fieldMask, DAY_OF_YEAR)) {
	if (isTransitionYear(date.getNormalizedYear())) {
	fixedDate = getFixedDateJan1(date, fixedDate);
	}
	// Add the offset, then subtract 1. (Make sure to avoid underflow.)
	fixedDate += internalGet(DAY_OF_YEAR);
	fixedDate--;
	} else {
	long firstDayOfWeek = LocalGregorianCalendar.getDayOfWeekDateOnOrBefore(fixedDate + 6,
	getFirstDayOfWeek());
	// If we have enough days in the first week, then move
	// to the previous week.
	if ((firstDayOfWeek - fixedDate) >= getMinimalDaysInFirstWeek()) {
	firstDayOfWeek -= 7;
	}
	if (isFieldSet(fieldMask, DAY_OF_WEEK)) {
	int dayOfWeek = internalGet(DAY_OF_WEEK);
	if (dayOfWeek != getFirstDayOfWeek()) {
	firstDayOfWeek = LocalGregorianCalendar.getDayOfWeekDateOnOrBefore(firstDayOfWeek + 6,
	dayOfWeek);
	}
	}
	fixedDate = firstDayOfWeek + 7 * ((long)internalGet(WEEK_OF_YEAR) - 1);
	}
	}
	return fixedDate;
	}

	/**
	* Returns the fixed date of the first day of the year (usually
	* January 1) before the specified date.
	*
	* @param date the date for which the first day of the year is
	* calculated. The date has to be in the cut-over year.
	* @param fixedDate the fixed date representation of the date
	*/
	private long getFixedDateJan1(LocalGregorianCalendar.Date date, long fixedDate) {
	Era era = date.getEra();
	if (date.getEra() != null && date.getYear() == 1) {
	for (int eraIndex = getEraIndex(date); eraIndex > 0; eraIndex--) {
	CalendarDate d = eras[eraIndex].getSinceDate();
	long fd = gcal.getFixedDate(d);
	// There might be multiple era transitions in a year.
	if (fd > fixedDate) {
	continue;
	}
	return fd;
	}
	}
	CalendarDate d = gcal.newCalendarDate(TimeZone.NO_TIMEZONE);
	d.setDate(date.getNormalizedYear(), Gregorian.JANUARY, 1);
	return gcal.getFixedDate(d);
	}

	/**
	* Returns the fixed date of the first date of the month (usually
	* the 1st of the month) before the specified date.
	*
	* @param date the date for which the first day of the month is
	* calculated. The date must be in the era transition year.
	* @param fixedDate the fixed date representation of the date
	*/
	private long getFixedDateMonth1(LocalGregorianCalendar.Date date,
	long fixedDate) {
	int eraIndex = getTransitionEraIndex(date);
	if (eraIndex != -1) {
	long transition = sinceFixedDates[eraIndex];
	// If the given date is on or after the transition date, then
	// return the transition date.
	if (transition <= fixedDate) {
	return transition;
	}
	}

	// Otherwise, we can use the 1st day of the month.
	return fixedDate - date.getDayOfMonth() + 1;
	}

	/**
	* Returns a LocalGregorianCalendar.Date produced from the specified fixed date.
	*
	* @param fd the fixed date
	*/
	private static LocalGregorianCalendar.Date getCalendarDate(long fd) {
	LocalGregorianCalendar.Date d = jcal.newCalendarDate(TimeZone.NO_TIMEZONE);
	jcal.getCalendarDateFromFixedDate(d, fd);
	return d;
	}

	/**
	* Returns the length of the specified month in the specified
	* Gregorian year. The year number must be normalized.
	*
	* @see GregorianCalendar#isLeapYear(int)
	*/
	private int monthLength(int month, int gregorianYear) {
	return CalendarUtils.isGregorianLeapYear(gregorianYear) ?
	GregorianCalendar.LEAP_MONTH_LENGTH[month] : GregorianCalendar.MONTH_LENGTH[month];
	}

	/**
	* Returns the length of the specified month in the year provided
	* by internalGet(YEAR).
	*
	* @see GregorianCalendar#isLeapYear(int)
	*/
	private int monthLength(int month) {
	assert jdate.isNormalized();
	return jdate.isLeapYear() ?
	GregorianCalendar.LEAP_MONTH_LENGTH[month] : GregorianCalendar.MONTH_LENGTH[month];
	}

	private int actualMonthLength() {
	int length = jcal.getMonthLength(jdate);
	int eraIndex = getTransitionEraIndex(jdate);
	if (eraIndex != -1) {
	long transitionFixedDate = sinceFixedDates[eraIndex];
	CalendarDate d = eras[eraIndex].getSinceDate();
	if (transitionFixedDate <= cachedFixedDate) {
	length -= d.getDayOfMonth() - 1;
	} else {
	length = d.getDayOfMonth() - 1;
	}
	}
	return length;
	}

	/**
	* Returns the index to the new era if the given date is in a
	* transition month. For example, if the give date is Heisei 1
	* (1989) January 20, then the era index for Heisei is
	* returned. Likewise, if the given date is Showa 64 (1989)
	* January 3, then the era index for Heisei is returned. If the
	* given date is not in any transition month, then -1 is returned.
	*/
	private static int getTransitionEraIndex(LocalGregorianCalendar.Date date) {
	int eraIndex = getEraIndex(date);
	CalendarDate transitionDate = eras[eraIndex].getSinceDate();
	if (transitionDate.getYear() == date.getNormalizedYear() &&
	transitionDate.getMonth() == date.getMonth()) {
	return eraIndex;
	}
	if (eraIndex < eras.length - 1) {
	transitionDate = eras[++eraIndex].getSinceDate();
	if (transitionDate.getYear() == date.getNormalizedYear() &&
	transitionDate.getMonth() == date.getMonth()) {
	return eraIndex;
	}
	}
	return -1;
	}

	private boolean isTransitionYear(int normalizedYear) {
	for (int i = eras.length - 1; i > 0; i--) {
	int transitionYear = eras[i].getSinceDate().getYear();
	if (normalizedYear == transitionYear) {
	return true;
	}
	if (normalizedYear > transitionYear) {
	break;
	}
	}
	return false;
	}

	private static int getEraIndex(LocalGregorianCalendar.Date date) {
	Era era = date.getEra();
	for (int i = eras.length - 1; i > 0; i--) {
	if (eras[i] == era) {
	return i;
	}
	}
	return 0;
	}

	/**
	* Returns this object if it's normalized (all fields and time are
	* in sync). Otherwise, a cloned object is returned after calling
	* complete() in lenient mode.
	*/
	private JapaneseImperialCalendar getNormalizedCalendar() {
	JapaneseImperialCalendar jc;
	if (isFullyNormalized()) {
	jc = this;
	} else {
	// Create a clone and normalize the calendar fields
	jc = (JapaneseImperialCalendar) this.clone();
	jc.setLenient(true);
	jc.complete();
	}
	return jc;
	}

	/**
	* After adjustments such as add(MONTH), add(YEAR), we don't want the
	* month to jump around. E.g., we don't want Jan 31 + 1 month to go to Mar
	* 3, we want it to go to Feb 28. Adjustments which might run into this
	* problem call this method to retain the proper month.
	*/
	private void pinDayOfMonth(LocalGregorianCalendar.Date date) {
	int year = date.getYear();
	int dom = date.getDayOfMonth();
	if (year != getMinimum(YEAR)) {
	date.setDayOfMonth(1);
	jcal.normalize(date);
	int monthLength = jcal.getMonthLength(date);
	if (dom > monthLength) {
	date.setDayOfMonth(monthLength);
	} else {
	date.setDayOfMonth(dom);
	}
	jcal.normalize(date);
	} else {
	LocalGregorianCalendar.Date d = jcal.getCalendarDate(Long.MIN_VALUE, getZone());
	LocalGregorianCalendar.Date realDate = jcal.getCalendarDate(time, getZone());
	long tod = realDate.getTimeOfDay();
	// Use an equivalent year.
	realDate.addYear(+400);
	realDate.setMonth(date.getMonth());
	realDate.setDayOfMonth(1);
	jcal.normalize(realDate);
	int monthLength = jcal.getMonthLength(realDate);
	if (dom > monthLength) {
	realDate.setDayOfMonth(monthLength);
	} else {
	if (dom < d.getDayOfMonth()) {
	realDate.setDayOfMonth(d.getDayOfMonth());
	} else {
	realDate.setDayOfMonth(dom);
	}
	}
	if (realDate.getDayOfMonth() == d.getDayOfMonth() && tod < d.getTimeOfDay()) {
	realDate.setDayOfMonth(Math.min(dom + 1, monthLength));
	}
	// restore the year.
	date.setDate(year, realDate.getMonth(), realDate.getDayOfMonth());
	// Don't normalize date here so as not to cause underflow.
	}
	}

	/**
	* Returns the new value after 'roll'ing the specified value and amount.
	*/
	private static int getRolledValue(int value, int amount, int min, int max) {
	assert value >= min && value <= max;
	int range = max - min + 1;
	amount %= range;
	int n = value + amount;
	if (n > max) {
	n -= range;
	} else if (n < min) {
	n += range;
	}
	assert n >= min && n <= max;
	return n;
	}

	/**
	* Returns the ERA. We need a special method for this because the
	* default ERA is the current era, but a zero (unset) ERA means before Meiji.
	*/
	private int internalGetEra() {
	return isSet(ERA) ? internalGet(ERA) : currentEra;
	}

	/**
	* Updates internal state.
	*/
	@java.io.Serial
	private void readObject(ObjectInputStream stream)
	throws IOException, ClassNotFoundException {
	stream.defaultReadObject();
	if (jdate == null) {
	jdate = jcal.newCalendarDate(getZone());
	cachedFixedDate = Long.MIN_VALUE;
	}
	}
	}

Back to index...