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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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/*
 * Copyright (c) 2012, Stephen Colebourne & Michael Nascimento Santos
 *
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 *  * Redistributions of source code must retain the above copyright notice,
 *    this list of conditions and the following disclaimer.
 *
 *  * Redistributions in binary form must reproduce the above copyright notice,
 *    this list of conditions and the following disclaimer in the documentation
 *    and/or other materials provided with the distribution.
 *
 *  * Neither the name of JSR-310 nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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 */
package java.time.chrono;

import static java.time.temporal.ChronoField.ALIGNED_DAY_OF_WEEK_IN_MONTH;
import static java.time.temporal.ChronoField.ALIGNED_DAY_OF_WEEK_IN_YEAR;
import static java.time.temporal.ChronoField.ALIGNED_WEEK_OF_MONTH;
import static java.time.temporal.ChronoField.ALIGNED_WEEK_OF_YEAR;
import static java.time.temporal.ChronoField.DAY_OF_MONTH;
import static java.time.temporal.ChronoField.MONTH_OF_YEAR;
import static java.time.temporal.ChronoField.YEAR;

import java.io.IOException;
import java.io.InvalidObjectException;
import java.io.ObjectInput;
import java.io.ObjectInputStream;
import java.io.ObjectOutput;
import java.io.Serializable;
import java.time.Clock;
import java.time.DateTimeException;
import java.time.LocalDate;
import java.time.LocalTime;
import java.time.ZoneId;
import java.time.temporal.ChronoField;
import java.time.temporal.TemporalAccessor;
import java.time.temporal.TemporalAdjuster;
import java.time.temporal.TemporalAmount;
import java.time.temporal.TemporalField;
import java.time.temporal.TemporalQuery;
import java.time.temporal.TemporalUnit;
import java.time.temporal.UnsupportedTemporalTypeException;
import java.time.temporal.ValueRange;


A date in the Hijrah calendar system.

 This date operates using one of several variants of the Hijrah calendar. 
 The Hijrah calendar has a different total of days in a year than Gregorian calendar, and the length of each month is based on the period of a complete revolution of the moon around the earth (as between successive new moons). Refer to the HijrahChronology for details of supported variants. 
 Each HijrahDate is created bound to a particular HijrahChronology, The same chronology is propagated to each HijrahDate computed from the date. To use a different Hijrah variant, its HijrahChronology can be used to create new HijrahDate instances. Alternatively, the withVariant method can be used to convert to a new HijrahChronology. 

This is a value-based class; use of identity-sensitive operations (including reference equality (==), identity hash code, or synchronization) on instances of HijrahDate may have unpredictable results and should be avoided. The equals method should be used for comparisons. 
Implementation Requirements:
This class is immutable and thread-safe.
Since:1.8
/**
 * A date in the Hijrah calendar system.
 * <p>
 * This date operates using one of several variants of the
 * {@linkplain HijrahChronology Hijrah calendar}.
 * <p>
 * The Hijrah calendar has a different total of days in a year than
 * Gregorian calendar, and the length of each month is based on the period
 * of a complete revolution of the moon around the earth
 * (as between successive new moons).
 * Refer to the {@link HijrahChronology} for details of supported variants.
 * <p>
 * Each HijrahDate is created bound to a particular HijrahChronology,
 * The same chronology is propagated to each HijrahDate computed from the date.
 * To use a different Hijrah variant, its HijrahChronology can be used
 * to create new HijrahDate instances.
 * Alternatively, the {@link #withVariant} method can be used to convert
 * to a new HijrahChronology.
 *
 * <p>
 * This is a <a href="{@docRoot}/java.base/java/lang/doc-files/ValueBased.html">value-based</a>
 * class; use of identity-sensitive operations (including reference equality
 * ({@code ==}), identity hash code, or synchronization) on instances of
 * {@code HijrahDate} may have unpredictable results and should be avoided.
 * The {@code equals} method should be used for comparisons.
 *
 * @implSpec
 * This class is immutable and thread-safe.
 *
 * @since 1.8
 */
public final class HijrahDate
        extends ChronoLocalDateImpl<HijrahDate>
        implements ChronoLocalDate, Serializable {

    
Serialization version.

/**
     * Serialization version.
     */
    private static final long serialVersionUID = -5207853542612002020L;
    
The Chronology of this HijrahDate.

/**
     * The Chronology of this HijrahDate.
     */
    private final transient HijrahChronology chrono;
    
The proleptic year.

/**
     * The proleptic year.
     */
    private final transient int prolepticYear;
    
The month-of-year.

/**
     * The month-of-year.
     */
    private final transient int monthOfYear;
    
The day-of-month.

/**
     * The day-of-month.
     */
    private final transient int dayOfMonth;

    //-------------------------------------------------------------------------
    
Obtains an instance of HijrahDate from the Hijrah proleptic year, month-of-year and day-of-month. 
Params:
  • prolepticYear –  the proleptic year to represent in the Hijrah calendar
  • monthOfYear –  the month-of-year to represent, from 1 to 12
  • dayOfMonth –  the day-of-month to represent, from 1 to 30
Throws:
Returns:the Hijrah date, never null
/**
     * Obtains an instance of {@code HijrahDate} from the Hijrah proleptic year,
     * month-of-year and day-of-month.
     *
     * @param prolepticYear  the proleptic year to represent in the Hijrah calendar
     * @param monthOfYear  the month-of-year to represent, from 1 to 12
     * @param dayOfMonth  the day-of-month to represent, from 1 to 30
     * @return the Hijrah date, never null
     * @throws DateTimeException if the value of any field is out of range
     */
    static HijrahDate of(HijrahChronology chrono, int prolepticYear, int monthOfYear, int dayOfMonth) {
        return new HijrahDate(chrono, prolepticYear, monthOfYear, dayOfMonth);
    }

    
Returns a HijrahDate for the chronology and epochDay.

Params:
  • chrono – The Hijrah chronology
  • epochDay – the epoch day
Returns:a HijrahDate for the epoch day; non-null
/**
     * Returns a HijrahDate for the chronology and epochDay.
     * @param chrono The Hijrah chronology
     * @param epochDay the epoch day
     * @return a HijrahDate for the epoch day; non-null
     */
    static HijrahDate ofEpochDay(HijrahChronology chrono, long epochDay) {
        return new HijrahDate(chrono, epochDay);
    }

    //-----------------------------------------------------------------------
    
Obtains the current HijrahDate of the Islamic Umm Al-Qura calendar in the default time-zone. 
 This will query the system clock in the default time-zone to obtain the current date. 

Using this method will prevent the ability to use an alternate clock for testing
because the clock is hard-coded.

Returns:the current date using the system clock and default time-zone, not null
/**
     * Obtains the current {@code HijrahDate} of the Islamic Umm Al-Qura calendar
     * in the default time-zone.
     * <p>
     * This will query the {@link Clock#systemDefaultZone() system clock} in the default
     * time-zone to obtain the current date.
     * <p>
     * Using this method will prevent the ability to use an alternate clock for testing
     * because the clock is hard-coded.
     *
     * @return the current date using the system clock and default time-zone, not null
     */
    public static HijrahDate now() {
        return now(Clock.systemDefaultZone());
    }

    
Obtains the current HijrahDate of the Islamic Umm Al-Qura calendar in the specified time-zone. 
 This will query the system clock to obtain the current date. Specifying the time-zone avoids dependence on the default time-zone. 

Using this method will prevent the ability to use an alternate clock for testing
because the clock is hard-coded.

Params:
  • zone –  the zone ID to use, not null
Returns:the current date using the system clock, not null
/**
     * Obtains the current {@code HijrahDate} of the Islamic Umm Al-Qura calendar
     * in the specified time-zone.
     * <p>
     * This will query the {@link Clock#system(ZoneId) system clock} to obtain the current date.
     * Specifying the time-zone avoids dependence on the default time-zone.
     * <p>
     * Using this method will prevent the ability to use an alternate clock for testing
     * because the clock is hard-coded.
     *
     * @param zone  the zone ID to use, not null
     * @return the current date using the system clock, not null
     */
    public static HijrahDate now(ZoneId zone) {
        return now(Clock.system(zone));
    }

    
Obtains the current HijrahDate of the Islamic Umm Al-Qura calendar from the specified clock. 
 This will query the specified clock to obtain the current date - today. Using this method allows the use of an alternate clock for testing. The alternate clock may be introduced using dependency injection. 
Params:
  • clock –  the clock to use, not null
Throws:
Returns:the current date, not null
/**
     * Obtains the current {@code HijrahDate} of the Islamic Umm Al-Qura calendar
     * from the specified clock.
     * <p>
     * This will query the specified clock to obtain the current date - today.
     * Using this method allows the use of an alternate clock for testing.
     * The alternate clock may be introduced using {@linkplain Clock dependency injection}.
     *
     * @param clock  the clock to use, not null
     * @return the current date, not null
     * @throws DateTimeException if the current date cannot be obtained
     */
    public static HijrahDate now(Clock clock) {
        return HijrahDate.ofEpochDay(HijrahChronology.INSTANCE, LocalDate.now(clock).toEpochDay());
    }

    
Obtains a HijrahDate of the Islamic Umm Al-Qura calendar from the proleptic-year, month-of-year and day-of-month fields. 
 This returns a HijrahDate with the specified fields. The day must be valid for the year and month, otherwise an exception will be thrown. 
Params:
  • prolepticYear –  the Hijrah proleptic-year
  • month –  the Hijrah month-of-year, from 1 to 12
  • dayOfMonth –  the Hijrah day-of-month, from 1 to 30
Throws:
  • DateTimeException – if the value of any field is out of range,
 or if the day-of-month is invalid for the month-year
Returns:the date in Hijrah calendar system, not null
/**
     * Obtains a {@code HijrahDate} of the Islamic Umm Al-Qura calendar
     * from the proleptic-year, month-of-year and day-of-month fields.
     * <p>
     * This returns a {@code HijrahDate} with the specified fields.
     * The day must be valid for the year and month, otherwise an exception will be thrown.
     *
     * @param prolepticYear  the Hijrah proleptic-year
     * @param month  the Hijrah month-of-year, from 1 to 12
     * @param dayOfMonth  the Hijrah day-of-month, from 1 to 30
     * @return the date in Hijrah calendar system, not null
     * @throws DateTimeException if the value of any field is out of range,
     *  or if the day-of-month is invalid for the month-year
     */
    public static HijrahDate of(int prolepticYear, int month, int dayOfMonth) {
        return HijrahChronology.INSTANCE.date(prolepticYear, month, dayOfMonth);
    }

    
Obtains a HijrahDate of the Islamic Umm Al-Qura calendar from a temporal object. 
 This obtains a date in the Hijrah calendar system based on the specified temporal. A TemporalAccessor represents an arbitrary set of date and time information, which this factory converts to an instance of HijrahDate. 
 The conversion typically uses the EPOCH_DAY field, which is standardized across calendar systems. 
 This method matches the signature of the functional interface TemporalQuery allowing it to be used as a query via method reference, HijrahDate::from. 
Params:
  • temporal –  the temporal object to convert, not null
Throws:
Returns:the date in Hijrah calendar system, not null
/**
     * Obtains a {@code HijrahDate} of the Islamic Umm Al-Qura calendar from a temporal object.
     * <p>
     * This obtains a date in the Hijrah calendar system based on the specified temporal.
     * A {@code TemporalAccessor} represents an arbitrary set of date and time information,
     * which this factory converts to an instance of {@code HijrahDate}.
     * <p>
     * The conversion typically uses the {@link ChronoField#EPOCH_DAY EPOCH_DAY}
     * field, which is standardized across calendar systems.
     * <p>
     * This method matches the signature of the functional interface {@link TemporalQuery}
     * allowing it to be used as a query via method reference, {@code HijrahDate::from}.
     *
     * @param temporal  the temporal object to convert, not null
     * @return the date in Hijrah calendar system, not null
     * @throws DateTimeException if unable to convert to a {@code HijrahDate}
     */
    public static HijrahDate from(TemporalAccessor temporal) {
        return HijrahChronology.INSTANCE.date(temporal);
    }

    //-----------------------------------------------------------------------
    
Constructs an HijrahDate with the proleptic-year, month-of-year and day-of-month fields. 
Params:
  • chrono – The chronology to create the date with
  • prolepticYear – the proleptic year
  • monthOfYear – the month of year
  • dayOfMonth – the day of month
/**
     * Constructs an {@code HijrahDate} with the proleptic-year, month-of-year and
     * day-of-month fields.
     *
     * @param chrono The chronology to create the date with
     * @param prolepticYear the proleptic year
     * @param monthOfYear the month of year
     * @param dayOfMonth the day of month
     */
    private HijrahDate(HijrahChronology chrono, int prolepticYear, int monthOfYear, int dayOfMonth) {
        // Computing the Gregorian day checks the valid ranges
        chrono.getEpochDay(prolepticYear, monthOfYear, dayOfMonth);

        this.chrono = chrono;
        this.prolepticYear = prolepticYear;
        this.monthOfYear = monthOfYear;
        this.dayOfMonth = dayOfMonth;
    }

    
Constructs an instance with the Epoch Day.

Params:
  • epochDay –  the epochDay
/**
     * Constructs an instance with the Epoch Day.
     *
     * @param epochDay  the epochDay
     */
    private HijrahDate(HijrahChronology chrono, long epochDay) {
        int[] dateInfo = chrono.getHijrahDateInfo((int)epochDay);

        this.chrono = chrono;
        this.prolepticYear = dateInfo[0];
        this.monthOfYear = dateInfo[1];
        this.dayOfMonth = dateInfo[2];
    }

    //-----------------------------------------------------------------------
    
Gets the chronology of this date, which is the Hijrah calendar system.

 The Chronology represents the calendar system in use. The era and other fields in ChronoField are defined by the chronology. 
Returns:the Hijrah chronology, not null
/**
     * Gets the chronology of this date, which is the Hijrah calendar system.
     * <p>
     * The {@code Chronology} represents the calendar system in use.
     * The era and other fields in {@link ChronoField} are defined by the chronology.
     *
     * @return the Hijrah chronology, not null
     */
    @Override
    public HijrahChronology getChronology() {
        return chrono;
    }

    
Gets the era applicable at this date.

 The Hijrah calendar system has one era, 'AH', defined by HijrahEra. 
Returns:the era applicable at this date, not null
/**
     * Gets the era applicable at this date.
     * <p>
     * The Hijrah calendar system has one era, 'AH',
     * defined by {@link HijrahEra}.
     *
     * @return the era applicable at this date, not null
     */
    @Override
    public HijrahEra getEra() {
        return HijrahEra.AH;
    }

    
Returns the length of the month represented by this date.


This returns the length of the month in days.
Month lengths in the Hijrah calendar system vary between 29 and 30 days.

Returns:the length of the month in days
/**
     * Returns the length of the month represented by this date.
     * <p>
     * This returns the length of the month in days.
     * Month lengths in the Hijrah calendar system vary between 29 and 30 days.
     *
     * @return the length of the month in days
     */
    @Override
    public int lengthOfMonth() {
        return chrono.getMonthLength(prolepticYear, monthOfYear);
    }

    
Returns the length of the year represented by this date.


This returns the length of the year in days.
A Hijrah calendar system year is typically shorter than
that of the ISO calendar system.

Returns:the length of the year in days
/**
     * Returns the length of the year represented by this date.
     * <p>
     * This returns the length of the year in days.
     * A Hijrah calendar system year is typically shorter than
     * that of the ISO calendar system.
     *
     * @return the length of the year in days
     */
    @Override
    public int lengthOfYear() {
        return chrono.getYearLength(prolepticYear);
    }

    //-----------------------------------------------------------------------
    @Override
    public ValueRange range(TemporalField field) {
        if (field instanceof ChronoField) {
            if (isSupported(field)) {
                ChronoField f = (ChronoField) field;
                switch (f) {
                    case DAY_OF_MONTH: return ValueRange.of(1, lengthOfMonth());
                    case DAY_OF_YEAR: return ValueRange.of(1, lengthOfYear());
                    case ALIGNED_WEEK_OF_MONTH: return ValueRange.of(1, 5);  // TODO
                    // TODO does the limited range of valid years cause years to
                    // start/end part way through? that would affect range
                }
                return getChronology().range(f);
            }
            throw new UnsupportedTemporalTypeException("Unsupported field: " + field);
        }
        return field.rangeRefinedBy(this);
    }

    @Override
    public long getLong(TemporalField field) {
        if (field instanceof ChronoField) {
            switch ((ChronoField) field) {
                case DAY_OF_WEEK: return getDayOfWeek();
                case ALIGNED_DAY_OF_WEEK_IN_MONTH: return ((dayOfMonth - 1) % 7) + 1;
                case ALIGNED_DAY_OF_WEEK_IN_YEAR: return ((getDayOfYear() - 1) % 7) + 1;
                case DAY_OF_MONTH: return this.dayOfMonth;
                case DAY_OF_YEAR: return this.getDayOfYear();
                case EPOCH_DAY: return toEpochDay();
                case ALIGNED_WEEK_OF_MONTH: return ((dayOfMonth - 1) / 7) + 1;
                case ALIGNED_WEEK_OF_YEAR: return ((getDayOfYear() - 1) / 7) + 1;
                case MONTH_OF_YEAR: return monthOfYear;
                case PROLEPTIC_MONTH: return getProlepticMonth();
                case YEAR_OF_ERA: return prolepticYear;
                case YEAR: return prolepticYear;
                case ERA: return getEraValue();
            }
            throw new UnsupportedTemporalTypeException("Unsupported field: " + field);
        }
        return field.getFrom(this);
    }

    private long getProlepticMonth() {
        return prolepticYear * 12L + monthOfYear - 1;
    }

    @Override
    public HijrahDate with(TemporalField field, long newValue) {
        if (field instanceof ChronoField) {
            ChronoField f = (ChronoField) field;
            // not using checkValidIntValue so EPOCH_DAY and PROLEPTIC_MONTH work
            chrono.range(f).checkValidValue(newValue, f);    // TODO: validate value
            int nvalue = (int) newValue;
            switch (f) {
                case DAY_OF_WEEK: return plusDays(newValue - getDayOfWeek());
                case ALIGNED_DAY_OF_WEEK_IN_MONTH: return plusDays(newValue - getLong(ALIGNED_DAY_OF_WEEK_IN_MONTH));
                case ALIGNED_DAY_OF_WEEK_IN_YEAR: return plusDays(newValue - getLong(ALIGNED_DAY_OF_WEEK_IN_YEAR));
                case DAY_OF_MONTH: return resolvePreviousValid(prolepticYear, monthOfYear, nvalue);
                case DAY_OF_YEAR: return plusDays(Math.min(nvalue, lengthOfYear()) - getDayOfYear());
                case EPOCH_DAY: return new HijrahDate(chrono, newValue);
                case ALIGNED_WEEK_OF_MONTH: return plusDays((newValue - getLong(ALIGNED_WEEK_OF_MONTH)) * 7);
                case ALIGNED_WEEK_OF_YEAR: return plusDays((newValue - getLong(ALIGNED_WEEK_OF_YEAR)) * 7);
                case MONTH_OF_YEAR: return resolvePreviousValid(prolepticYear, nvalue, dayOfMonth);
                case PROLEPTIC_MONTH: return plusMonths(newValue - getProlepticMonth());
                case YEAR_OF_ERA: return resolvePreviousValid(prolepticYear >= 1 ? nvalue : 1 - nvalue, monthOfYear, dayOfMonth);
                case YEAR: return resolvePreviousValid(nvalue, monthOfYear, dayOfMonth);
                case ERA: return resolvePreviousValid(1 - prolepticYear, monthOfYear, dayOfMonth);
            }
            throw new UnsupportedTemporalTypeException("Unsupported field: " + field);
        }
        return super.with(field, newValue);
    }

    private HijrahDate resolvePreviousValid(int prolepticYear, int month, int day) {
        int monthDays = chrono.getMonthLength(prolepticYear, month);
        if (day > monthDays) {
            day = monthDays;
        }
        return HijrahDate.of(chrono, prolepticYear, month, day);
    }

    
{@inheritDoc}

Throws:
/**
     * {@inheritDoc}
     * @throws DateTimeException if unable to make the adjustment.
     *     For example, if the adjuster requires an ISO chronology
     * @throws ArithmeticException {@inheritDoc}
     */
    @Override
    public  HijrahDate with(TemporalAdjuster adjuster) {
        return super.with(adjuster);
    }

    
Returns a HijrahDate with the Chronology requested. 

The year, month, and day are checked against the new requested
HijrahChronology.  If the chronology has a shorter month length
for the month, the day is reduced to be the last day of the month.

Params:
  • chronology – the new HijrahChonology, non-null
Returns:a HijrahDate with the requested HijrahChronology, non-null
/**
     * Returns a {@code HijrahDate} with the Chronology requested.
     * <p>
     * The year, month, and day are checked against the new requested
     * HijrahChronology.  If the chronology has a shorter month length
     * for the month, the day is reduced to be the last day of the month.
     *
     * @param chronology the new HijrahChonology, non-null
     * @return a HijrahDate with the requested HijrahChronology, non-null
     */
    public HijrahDate withVariant(HijrahChronology chronology) {
        if (chrono == chronology) {
            return this;
        }
        // Like resolvePreviousValid the day is constrained to stay in the same month
        int monthDays = chronology.getDayOfYear(prolepticYear, monthOfYear);
        return HijrahDate.of(chronology, prolepticYear, monthOfYear,(dayOfMonth > monthDays) ? monthDays : dayOfMonth );
    }

    
{@inheritDoc}

Throws:
/**
     * {@inheritDoc}
     * @throws DateTimeException {@inheritDoc}
     * @throws ArithmeticException {@inheritDoc}
     */
    @Override
    public HijrahDate plus(TemporalAmount amount) {
        return super.plus(amount);
    }

    
{@inheritDoc}

Throws:
/**
     * {@inheritDoc}
     * @throws DateTimeException {@inheritDoc}
     * @throws ArithmeticException {@inheritDoc}
     */
    @Override
    public HijrahDate minus(TemporalAmount amount) {
        return super.minus(amount);
    }

    @Override
    public long toEpochDay() {
        return chrono.getEpochDay(prolepticYear, monthOfYear, dayOfMonth);
    }

    
Gets the day-of-year field.

 This method returns the primitive int value for the day-of-year. 
Returns:the day-of-year
/**
     * Gets the day-of-year field.
     * <p>
     * This method returns the primitive {@code int} value for the day-of-year.
     *
     * @return the day-of-year
     */
    private int getDayOfYear() {
        return chrono.getDayOfYear(prolepticYear, monthOfYear) + dayOfMonth;
    }

    
Gets the day-of-week value.

Returns:the day-of-week; computed from the epochday
/**
     * Gets the day-of-week value.
     *
     * @return the day-of-week; computed from the epochday
     */
    private int getDayOfWeek() {
        int dow0 = Math.floorMod(toEpochDay() + 3, 7);
        return dow0 + 1;
    }

    
Gets the Era of this date.

Returns:the Era of this date; computed from epochDay
/**
     * Gets the Era of this date.
     *
     * @return the Era of this date; computed from epochDay
     */
    private int getEraValue() {
        return (prolepticYear > 1 ? 1 : 0);
    }

    //-----------------------------------------------------------------------
    
Checks if the year is a leap year, according to the Hijrah calendar system rules.

Returns:true if this date is in a leap year
/**
     * Checks if the year is a leap year, according to the Hijrah calendar system rules.
     *
     * @return true if this date is in a leap year
     */
    @Override
    public boolean isLeapYear() {
        return chrono.isLeapYear(prolepticYear);
    }

    //-----------------------------------------------------------------------
    @Override
    HijrahDate plusYears(long years) {
        if (years == 0) {
            return this;
        }
        int newYear = Math.addExact(this.prolepticYear, (int)years);
        return resolvePreviousValid(newYear, monthOfYear, dayOfMonth);
    }

    @Override
    HijrahDate plusMonths(long monthsToAdd) {
        if (monthsToAdd == 0) {
            return this;
        }
        long monthCount = prolepticYear * 12L + (monthOfYear - 1);
        long calcMonths = monthCount + monthsToAdd;  // safe overflow
        int newYear = chrono.checkValidYear(Math.floorDiv(calcMonths, 12L));
        int newMonth = (int)Math.floorMod(calcMonths, 12L) + 1;
        return resolvePreviousValid(newYear, newMonth, dayOfMonth);
    }

    @Override
    HijrahDate plusWeeks(long weeksToAdd) {
        return super.plusWeeks(weeksToAdd);
    }

    @Override
    HijrahDate plusDays(long days) {
        return new HijrahDate(chrono, toEpochDay() + days);
    }

    @Override
    public HijrahDate plus(long amountToAdd, TemporalUnit unit) {
        return super.plus(amountToAdd, unit);
    }

    @Override
    public HijrahDate minus(long amountToSubtract, TemporalUnit unit) {
        return super.minus(amountToSubtract, unit);
    }

    @Override
    HijrahDate minusYears(long yearsToSubtract) {
        return super.minusYears(yearsToSubtract);
    }

    @Override
    HijrahDate minusMonths(long monthsToSubtract) {
        return super.minusMonths(monthsToSubtract);
    }

    @Override
    HijrahDate minusWeeks(long weeksToSubtract) {
        return super.minusWeeks(weeksToSubtract);
    }

    @Override
    HijrahDate minusDays(long daysToSubtract) {
        return super.minusDays(daysToSubtract);
    }

    @Override        // for javadoc and covariant return type
    @SuppressWarnings("unchecked")
    public final ChronoLocalDateTime<HijrahDate> atTime(LocalTime localTime) {
        return (ChronoLocalDateTime<HijrahDate>)super.atTime(localTime);
    }

    @Override
    public ChronoPeriod until(ChronoLocalDate endDate) {
        // TODO: untested
        HijrahDate end = getChronology().date(endDate);
        long totalMonths = (end.prolepticYear - this.prolepticYear) * 12 + (end.monthOfYear - this.monthOfYear);  // safe
        int days = end.dayOfMonth - this.dayOfMonth;
        if (totalMonths > 0 && days < 0) {
            totalMonths--;
            HijrahDate calcDate = this.plusMonths(totalMonths);
            days = (int) (end.toEpochDay() - calcDate.toEpochDay());  // safe
        } else if (totalMonths < 0 && days > 0) {
            totalMonths++;
            days -= end.lengthOfMonth();
        }
        long years = totalMonths / 12;  // safe
        int months = (int) (totalMonths % 12);  // safe
        return getChronology().period(Math.toIntExact(years), months, days);
    }

    //-------------------------------------------------------------------------
    
Compares this date to another date, including the chronology.

 Compares this HijrahDate with another ensuring that the date is the same. 
 Only objects of type HijrahDate are compared, other types return false. To compare the dates of two TemporalAccessor instances, including dates in two different chronologies, use ChronoField.EPOCH_DAY as a comparator. 
Params:
  • obj –  the object to check, null returns false
Returns:true if this is equal to the other date and the Chronologies are equal
/**
     * Compares this date to another date, including the chronology.
     * <p>
     * Compares this {@code HijrahDate} with another ensuring that the date is the same.
     * <p>
     * Only objects of type {@code HijrahDate} are compared, other types return false.
     * To compare the dates of two {@code TemporalAccessor} instances, including dates
     * in two different chronologies, use {@link ChronoField#EPOCH_DAY} as a comparator.
     *
     * @param obj  the object to check, null returns false
     * @return true if this is equal to the other date and the Chronologies are equal
     */
    @Override  // override for performance
    public boolean equals(Object obj) {
        if (this == obj) {
            return true;
        }
        if (obj instanceof HijrahDate) {
            HijrahDate otherDate = (HijrahDate) obj;
            return prolepticYear == otherDate.prolepticYear
                && this.monthOfYear == otherDate.monthOfYear
                && this.dayOfMonth == otherDate.dayOfMonth
                && getChronology().equals(otherDate.getChronology());
        }
        return false;
    }

    
A hash code for this date.

Returns:a suitable hash code based only on the Chronology and the date
/**
     * A hash code for this date.
     *
     * @return a suitable hash code based only on the Chronology and the date
     */
    @Override  // override for performance
    public int hashCode() {
        int yearValue = prolepticYear;
        int monthValue = monthOfYear;
        int dayValue = dayOfMonth;
        return getChronology().getId().hashCode() ^ (yearValue & 0xFFFFF800)
                ^ ((yearValue << 11) + (monthValue << 6) + (dayValue));
    }

    //-----------------------------------------------------------------------
    
Defend against malicious streams.

Params:
  • s – the stream to read
Throws:
/**
     * Defend against malicious streams.
     *
     * @param s the stream to read
     * @throws InvalidObjectException always
     */
    private void readObject(ObjectInputStream s) throws InvalidObjectException {
        throw new InvalidObjectException("Deserialization via serialization delegate");
    }

    
Writes the object using a
dedicated serialized form.

@serialData

 out.writeByte(6);                 // identifies a HijrahDate
 out.writeObject(chrono);          // the HijrahChronology variant
 out.writeInt(get(YEAR));
 out.writeByte(get(MONTH_OF_YEAR));
 out.writeByte(get(DAY_OF_MONTH));

Returns:the instance of Ser, not null
/**
     * Writes the object using a
     * <a href="../../../serialized-form.html#java.time.chrono.Ser">dedicated serialized form</a>.
     * @serialData
     * <pre>
     *  out.writeByte(6);                 // identifies a HijrahDate
     *  out.writeObject(chrono);          // the HijrahChronology variant
     *  out.writeInt(get(YEAR));
     *  out.writeByte(get(MONTH_OF_YEAR));
     *  out.writeByte(get(DAY_OF_MONTH));
     * </pre>
     *
     * @return the instance of {@code Ser}, not null
     */
    private Object writeReplace() {
        return new Ser(Ser.HIJRAH_DATE_TYPE, this);
    }

    void writeExternal(ObjectOutput out) throws IOException {
        // HijrahChronology is implicit in the Hijrah_DATE_TYPE
        out.writeObject(getChronology());
        out.writeInt(get(YEAR));
        out.writeByte(get(MONTH_OF_YEAR));
        out.writeByte(get(DAY_OF_MONTH));
    }

    static HijrahDate readExternal(ObjectInput in) throws IOException, ClassNotFoundException {
        HijrahChronology chrono = (HijrahChronology) in.readObject();
        int year = in.readInt();
        int month = in.readByte();
        int dayOfMonth = in.readByte();
        return chrono.date(year, month, dayOfMonth);
    }

}