IndianCalendar.java
// © 2016 and later: Unicode, Inc. and others.
// License & terms of use: http://www.unicode.org/copyright.html
/*
*******************************************************************************
* Copyright (C) 1996-2011, International Business Machines Corporation and *
* others. All Rights Reserved. *
*******************************************************************************
*/
package com.ibm.icu.util;
import com.ibm.icu.util.ULocale.Category;
import java.util.Date;
import java.util.Locale;
/**
* <code>IndianCalendar</code> is a subclass of <code>GregorianCalendar</code> that numbers years
* since the birth of the Buddha. This is the civil calendar which is accepted by government of
* India as Indian National Calendar. The two calendars most widely used in India today are the
* Vikrama calendar followed in North India and the Shalivahana or Saka calendar which is followed
* in South India and Maharashtra.
*
* <p>A variant of the Shalivahana Calendar was reformed and standardized as the Indian National
* calendar in 1957.
*
* <p>Some details of Indian National Calendar (to be implemented) : The Months Month Length Start
* date (Gregorian) ================================================= 1 Chaitra 30/31 March 22* 2
* Vaisakha 31 April 21 3 Jyaistha 31 May 22 4 Asadha 31 June 22 5 Sravana 31 July 23 6 Bhadra 31
* August 23 7 Asvina 30 September 23 8 Kartika 30 October 23 9 Agrahayana 30 November 22 10 Pausa
* 30 December 22 11 Magha 30 January 21 12 Phalguna 30 February 20
*
* <p>In leap years, Chaitra has 31 days and starts on March 21 instead. The leap years of Gregorian
* calendar and Indian National Calendar are in synchornization. So When its a leap year in
* Gregorian calendar then Chaitra has 31 days.
*
* <p>The Years Years are counted in the Saka Era, which starts its year 0 in 78AD (by gregorian
* calendar). So for eg. 9th June 2006 by Gregorian Calendar, is same as 19th of Jyaistha in 1928 of
* Saka era by Indian National Calendar.
*
* <p>The Indian Calendar has only one allowable era: <code>Saka Era</code>. If the calendar is not
* in lenient mode (see <code>setLenient</code>), dates before 1/1/1 Saka Era are rejected with an
* <code>IllegalArgumentException</code>.
*
* <p>This class should not be subclassed.
*
* <p>IndianCalendar usually should be instantiated using {@link
* com.ibm.icu.util.Calendar#getInstance(ULocale)} passing in a <code>ULocale</code> with the tag
* <code>"@calendar=Indian"</code>.
*
* @see com.ibm.icu.util.Calendar
* @see com.ibm.icu.util.GregorianCalendar
* @stable ICU 3.8
*/
public class IndianCalendar extends Calendar {
// jdk1.4.2 serialver
private static final long serialVersionUID = 3617859668165014834L;
/**
* Constant for Chaitra, the 1st month of the Indian year.
*
* @stable ICU 3.8
*/
public static final int CHAITRA = 0;
/**
* Constant for Vaisakha, the 2nd month of the Indian year.
*
* @stable ICU 3.8
*/
public static final int VAISAKHA = 1;
/**
* Constant for Jyaistha, the 3rd month of the Indian year.
*
* @stable ICU 3.8
*/
public static final int JYAISTHA = 2;
/**
* Constant for Asadha, the 4th month of the Indian year.
*
* @stable ICU 3.8
*/
public static final int ASADHA = 3;
/**
* Constant for Sravana, the 5th month of the Indian year.
*
* @stable ICU 3.8
*/
public static final int SRAVANA = 4;
/**
* Constant for Bhadra, the 6th month of the Indian year.
*
* @stable ICU 3.8
*/
public static final int BHADRA = 5;
/**
* Constant for Asvina, the 7th month of the Indian year.
*
* @stable ICU 3.8
*/
public static final int ASVINA = 6;
/**
* Constant for Kartika, the 8th month of the Indian year.
*
* @stable ICU 3.8
*/
public static final int KARTIKA = 7;
/**
* Constant for Agrahayana, the 9th month of the Indian year.
*
* @stable ICU 3.8
*/
public static final int AGRAHAYANA = 8;
/**
* Constant for Pausa, the 10th month of the Indian year.
*
* @stable ICU 3.8
*/
public static final int PAUSA = 9;
/**
* Constant for Magha, the 11th month of the Indian year.
*
* @stable ICU 3.8
*/
public static final int MAGHA = 10;
/**
* Constant for Phalguna, the 12th month of the Indian year.
*
* @stable ICU 3.8
*/
public static final int PHALGUNA = 11;
// -------------------------------------------------------------------------
// Constructors...
// -------------------------------------------------------------------------
/**
* Constant for the Indian Era. This is the only allowable <code>ERA</code> value for the Indian
* calendar.
*
* @see com.ibm.icu.util.Calendar#ERA
* @stable ICU 3.8
*/
public static final int IE = 0;
/**
* Constructs a <code>IndianCalendar</code> using the current time in the default time zone with
* the default <code>FORMAT</code> locale.
*
* @see Category#FORMAT
* @stable ICU 3.8
*/
public IndianCalendar() {
this(TimeZone.getDefault(), ULocale.getDefault(Category.FORMAT));
}
/**
* Constructs a <code>IndianCalendar</code> based on the current time in the given time zone
* with the default <code>FORMAT</code> locale.
*
* @param zone the given time zone.
* @see Category#FORMAT
* @stable ICU 3.8
*/
public IndianCalendar(TimeZone zone) {
this(zone, ULocale.getDefault(Category.FORMAT));
}
/**
* Constructs a <code>IndianCalendar</code> based on the current time in the default time zone
* with the given locale.
*
* @param aLocale the given locale.
* @stable ICU 3.8
*/
public IndianCalendar(Locale aLocale) {
this(TimeZone.forLocaleOrDefault(aLocale), aLocale);
}
/**
* Constructs a <code>IndianCalendar</code> based on the current time in the default time zone
* with the given locale.
*
* @param locale the given ulocale.
* @stable ICU 3.8
*/
public IndianCalendar(ULocale locale) {
this(TimeZone.forULocaleOrDefault(locale), locale);
}
/**
* Constructs a <code>IndianCalendar</code> 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.
* @stable ICU 3.8
*/
public IndianCalendar(TimeZone zone, Locale aLocale) {
super(zone, aLocale);
setTimeInMillis(System.currentTimeMillis());
}
/**
* Constructs a <code>IndianCalendar</code> based on the current time in the given time zone
* with the given locale.
*
* @param zone the given time zone.
* @param locale the given ulocale.
* @stable ICU 3.8
*/
public IndianCalendar(TimeZone zone, ULocale locale) {
super(zone, locale);
setTimeInMillis(System.currentTimeMillis());
}
/**
* Constructs a <code>IndianCalendar</code> with the given date set in the default time zone
* with the default <code>FORMAT</code> locale.
*
* @param date The date to which the new calendar is set.
* @see Category#FORMAT
* @stable ICU 3.8
*/
public IndianCalendar(Date date) {
super(TimeZone.getDefault(), ULocale.getDefault(Category.FORMAT));
this.setTime(date);
}
/**
* Constructs a <code>IndianCalendar</code> with the given date set in the default time zone
* with the default <code>FORMAT</code> locale.
*
* @param year The value used to set the calendar's {@link #YEAR YEAR} time field.
* @param month The value used to set the calendar's {@link #MONTH MONTH} time field. The value
* is 0-based. e.g., 0 for January.
* @param date The value used to set the calendar's {@link #DATE DATE} time field.
* @see Category#FORMAT
* @stable ICU 3.8
*/
public IndianCalendar(int year, int month, int date) {
super(TimeZone.getDefault(), ULocale.getDefault(Category.FORMAT));
this.set(Calendar.YEAR, year);
this.set(Calendar.MONTH, month);
this.set(Calendar.DATE, date);
}
/**
* Constructs a IndianCalendar with the given date and time set for the default time zone with
* the default <code>FORMAT</code> locale.
*
* @param year The value used to set the calendar's {@link #YEAR YEAR} time field.
* @param month The value used to set the calendar's {@link #MONTH MONTH} time field. The value
* is 0-based. e.g., 0 for January.
* @param date The value used to set the calendar's {@link #DATE DATE} time field.
* @param hour The value used to set the calendar's {@link #HOUR_OF_DAY HOUR_OF_DAY} time field.
* @param minute The value used to set the calendar's {@link #MINUTE MINUTE} time field.
* @param second The value used to set the calendar's {@link #SECOND SECOND} time field.
* @see Category#FORMAT
* @stable ICU 3.8
*/
public IndianCalendar(int year, int month, int date, int hour, int minute, int second) {
super(TimeZone.getDefault(), ULocale.getDefault(Category.FORMAT));
this.set(Calendar.YEAR, year);
this.set(Calendar.MONTH, month);
this.set(Calendar.DATE, date);
this.set(Calendar.HOUR_OF_DAY, hour);
this.set(Calendar.MINUTE, minute);
this.set(Calendar.SECOND, second);
}
// -------------------------------------------------------------------------
// The only practical difference from a Gregorian calendar is that years
// are numbered since the Saka Era. A couple of overrides will
// take care of that....
// -------------------------------------------------------------------------
// Starts in 78 AD,
private static final int INDIAN_ERA_START = 78;
// The Indian year starts 80 days later than the Gregorian year.
private static final int INDIAN_YEAR_START = 80;
/**
* {@inheritDoc}
*
* @stable ICU 3.8
*/
@Override
protected int handleGetExtendedYear() {
int year;
if (newerField(EXTENDED_YEAR, YEAR) == EXTENDED_YEAR) {
year = internalGet(EXTENDED_YEAR, 1);
} else {
// Ignore the era, as there is only one
year = internalGet(YEAR, 1);
}
return year;
}
/**
* {@inheritDoc}
*
* @stable ICU 3.8
*/
@Override
protected int handleGetYearLength(int extendedYear) {
return super.handleGetYearLength(extendedYear);
}
/**
* {@inheritDoc}
*
* @stable ICU 3.8
*/
@Override
protected int handleGetMonthLength(int extendedYear, int month) {
if (month < 0 || month > 11) {
int[] remainder = new int[1];
extendedYear += floorDivide(month, 12, remainder);
month = remainder[0];
}
if (isGregorianLeapYear(extendedYear + INDIAN_ERA_START) && month == 0) {
return 31;
}
if (month >= 1 && month <= 5) {
return 31;
}
return 30;
}
/**
* {@inheritDoc}
*
* @stable ICU 3.8
*/
@Override
protected void handleComputeFields(int julianDay) {
double jdAtStartOfGregYear;
int leapMonth, IndianYear, yday, IndianMonth, IndianDayOfMonth, mday;
int gregorianYear =
getGregorianYear(); // Stores gregorian date corresponding to Julian day;
IndianYear = gregorianYear - INDIAN_ERA_START; // Year in Saka era
jdAtStartOfGregYear =
gregorianToJD(
gregorianYear,
0 /* first month in 0 base */,
1); // JD at start of Gregorian year
yday = (int) (julianDay - jdAtStartOfGregYear); // Day number in Gregorian year (starting
// from 0)
if (yday < INDIAN_YEAR_START) {
// Day is at the end of the preceding Saka year
IndianYear -= 1;
leapMonth =
isGregorianLeapYear(gregorianYear - 1)
? 31
: 30; // Days in leapMonth this year, previous Gregorian year
yday += leapMonth + (31 * 5) + (30 * 3) + 10;
} else {
leapMonth = isGregorianLeapYear(gregorianYear) ? 31 : 30; // Days in leapMonth this year
yday -= INDIAN_YEAR_START;
}
if (yday < leapMonth) {
IndianMonth = 0;
IndianDayOfMonth = yday + 1;
} else {
mday = yday - leapMonth;
if (mday < (31 * 5)) {
IndianMonth = mday / 31 + 1;
IndianDayOfMonth = (mday % 31) + 1;
} else {
mday -= 31 * 5;
IndianMonth = mday / 30 + 6;
IndianDayOfMonth = (mday % 30) + 1;
}
}
internalSet(ERA, 0);
internalSet(EXTENDED_YEAR, IndianYear);
internalSet(YEAR, IndianYear);
internalSet(MONTH, IndianMonth);
internalSet(ORDINAL_MONTH, IndianMonth);
internalSet(DAY_OF_MONTH, IndianDayOfMonth);
internalSet(DAY_OF_YEAR, yday + 1); // yday is 0-based
}
private static final int LIMITS[][] = {
// Minimum Greatest Least Maximum
// Minimum Maximum
{0, 0, 0, 0}, // ERA
{-5000000, -5000000, 5000000, 5000000}, // YEAR
{0, 0, 11, 11}, // MONTH
{1, 1, 52, 53}, // WEEK_OF_YEAR
{
/* */
}, // WEEK_OF_MONTH
{1, 1, 30, 31}, // DAY_OF_MONTH
{1, 1, 365, 366}, // DAY_OF_YEAR
{
/* */
}, // DAY_OF_WEEK
{-1, -1, 5, 5}, // DAY_OF_WEEK_IN_MONTH
{
/* */
}, // AM_PM
{
/* */
}, // HOUR
{
/* */
}, // HOUR_OF_DAY
{
/* */
}, // MINUTE
{
/* */
}, // SECOND
{
/* */
}, // MILLISECOND
{
/* */
}, // ZONE_OFFSET
{
/* */
}, // DST_OFFSET
{-5000000, -5000000, 5000000, 5000000}, // YEAR_WOY
{
/* */
}, // DOW_LOCAL
{-5000000, -5000000, 5000000, 5000000}, // EXTENDED_YEAR
{
/* */
}, // JULIAN_DAY
{
/* */
}, // MILLISECONDS_IN_DAY
{
/* */
}, // IS_LEAP_MONTH
{0, 0, 11, 11}, // ORDINAL_MONTH
};
/**
* {@inheritDoc}
*
* @stable ICU 3.8
*/
@Override
protected int handleGetLimit(int field, int limitType) {
return LIMITS[field][limitType];
}
/**
* {@inheritDoc}
*
* @stable ICU 3.8
*/
@Override
protected int handleComputeMonthStart(int year, int month, boolean useMonth) {
// month is 0 based; converting it to 1-based
int imonth;
// If the month is out of range, adjust it into range, and adjust the extended year
// accordingly
if (month < 0 || month > 11) {
year += month / 12;
month %= 12;
}
imonth = month + 1;
double jd = IndianToJD(year, imonth, 1);
return (int) jd;
}
/*
* This routine converts an Indian date to the corresponding Julian date"
* @param year The year in Saka Era according to Indian calendar.
* @param month The month according to Indian calendar (between 1 to 12)
* @param date The date in month
*/
private double IndianToJD(int year, int month, int date) {
int leapMonth, gyear, m;
double start, jd;
gyear = year + INDIAN_ERA_START;
if (isGregorianLeapYear(gyear)) {
leapMonth = 31;
start = gregorianToJD(gyear, 2 /* third month in 0 based */, 21);
} else {
leapMonth = 30;
start = gregorianToJD(gyear, 2 /* third month in 0 based */, 22);
}
if (month == 1) {
jd = start + (date - 1);
} else {
jd = start + leapMonth;
m = month - 2;
m = Math.min(m, 5);
jd += m * 31;
if (month >= 8) {
m = month - 7;
jd += m * 30;
}
jd += date - 1;
}
return jd;
}
private static final int INDIAN_CALENDAR_RELATED_YEAR_DIFFERENCE = 79;
/**
* @internal
* @deprecated This API is ICU internal only.
*/
@Override
@Deprecated
protected final int getRelatedYearDifference() {
return INDIAN_CALENDAR_RELATED_YEAR_DIFFERENCE;
}
/*
* The following function is not needed for basic calendar functioning.
* This routine converts a gregorian date to the corresponding Julian date"
* @param year The year in standard Gregorian calendar (AD/BC) .
* @param month The month according to Gregorian calendar (between 0 to 11)
* @param date The date in month
*/
private double gregorianToJD(int year, int month, int date) {
return computeGregorianMonthStart(year, month) + date - 0.5;
}
/**
* {@inheritDoc}
*
* @stable ICU 3.8
*/
@Override
public String getType() {
return "indian";
}
}