Package net.time4j.calendar.hindu

Class HinduCalendar

java.lang.Object

net.time4j.engine.ChronoEntity<D>

net.time4j.engine.CalendarVariant<HinduCalendar>

net.time4j.calendar.hindu.HinduCalendar

All Implemented Interfaces:

Serializable, Comparable<HinduCalendar>, CalendarDate, ChronoDisplay, Temporal<CalendarDate>, VariantSource, LocalizedPatternSupport

@CalendarType("hindu")
public final class HinduCalendar
extends CalendarVariant<HinduCalendar>
implements LocalizedPatternSupport

The traditional Hindu calendar which exists in many regional variants throughout the Indian subcontinent.

This version actually supports all algorithmic variants including the old Hindu calendar. These variants are described in the book "Calendrical Calculations" by Dershowitz/Reingold. Real Hindu calendars published on websites can nevertheless deviate in detail. Users who wish to support modern Hindu calendars can start with the enum HinduRule in order to construct a suitable variant. For example, it is possible to set the default era for all calendar objects by setting the desired era on the variant. Users can also configure astronomic calculations to be applied instead of the traditional ways to calculate Hindu calendar dates.

Supported elements

Following elements which are declared as constants are registered by this class:

• DAY_OF_WEEK
• DAY_OF_MONTH
• DAY_OF_YEAR
• MONTH_OF_YEAR
• YEAR_OF_ERA
• ERA

Furthermore, all elements defined in EpochDays and CommonElements.RELATED_GREGORIAN_YEAR are supported.

Calendar arithmetic and time units

A date arithmetic using units beyond the class CalendarDays is not offered. But there are methods like previousMonth() or nextYear(). About years, user can also use expressions like with(YEAR_OF_ERA, getYear() + amount).

Formatting and parsing

This calendar can deploy the same localized resources like the Indian national calendar. Example:

     ChronoFormatter<HinduCalendar> f =
          ChronoFormatter.ofPattern(
              "G, d. MMMM yyyy",
              PatternType.CLDR,
              Locale.ENGLISH,
              HinduCalendar.family());
     HinduCalendar cal = HinduCalendar.ofOldSolar(3101, HinduMonth.of(IndianMonth.MAGHA).getRasi(), 19);
     assertThat(
          f.print(cal),
          is("K.Y, 19. Magha 3101"));
 

Possible leap months or leap days can be printed and parsed, too. If no special format attribute is specified and the text width to be used is wide then the localized word for "adhika" will be printed in front of leap months or days. Example for a short display using format attributes for handling leap indicators and the orientation of leap indicator:

     ChronoFormatter<HinduCalendar> f =
          ChronoFormatter.ofPattern("M yyyy, d", PatternType.CLDR, Locale.ENGLISH, HinduCalendar.family())
              .with(HinduPrimitive.ADHIKA_INDICATOR, '*')
              .with(HinduPrimitive.ADHIKA_IS_TRAILING, true);
     HinduCalendar cal =
          HinduCalendar.of(
              HinduRule.AMANTA.variant(),
              HinduEra.VIKRAMA,
              1549,
              HinduMonth.of(IndianMonth.VAISHAKHA).withLeap(),
              HinduDay.valueOf(3));
     assertThat(
          f.print(cal),
          is("2* 1549, 3"));
 

Other number systems can be used in the usual way by obtaining a modified copy of the formatter with an expression like f.with(Attributes.NUMBER_SYSTEM, NumberSystem.DEVANAGARI).

Oddities

The Hindu calendar knows lost days and leap days. And the lunisolar variants also know lost months (rare) and leap months. This is the main reason why days and months are not modelled as integers. So users cannot rely on simple home grown integer arithmetic to look for example for the next valid day but must use the existing element queries, element manipulations and expressions based on the available methods like nextDay() or nextMonth(). Any date input in doubt should also be validated using isValid(HinduVariant, HinduEra, int, HinduMonth, HinduDay) when creating a calendar date.

Since:

5.7

Author:

Meno Hochschild

See Also:

IndianCalendar, HinduVariant, HinduRule, AryaSiddhanta, NumberSystem, HinduPrimitive.ADHIKA_INDICATOR, HinduPrimitive.ADHIKA_IS_TRAILING, Serialized Form

Field Summary

Fields

Modifier and Type	Field	Description
static AdjustableTextElement<HinduDay>	DAY_OF_MONTH	Represents the Hindu day of month.
static StdCalendarElement<Weekday,HinduCalendar>	DAY_OF_WEEK	Represents the Hindu day of week.
static StdCalendarElement<Integer,HinduCalendar>	DAY_OF_YEAR	Represents the Hindu day of year.
static ChronoElement<HinduEra>	ERA	Represents the Hindu era.
static AdjustableTextElement<HinduMonth>	MONTH_OF_YEAR	Represents the Hindu month.
static StdCalendarElement<Integer,HinduCalendar>	YEAR_OF_ERA	Represents the Hindu year.

Method Summary

Modifier and Type	Method	Description
GeneralTimestamp<HinduCalendar>	at(PlainTime time)	Creates a new local timestamp with this date and given civil time.
GeneralTimestamp<HinduCalendar>	atTime(int hour, int minute)	Is equivalent to at(PlainTime.of(hour, minute)).
boolean	equals(Object obj)	Compares the whole state of this instance with given object.
static CalendarFamily<HinduCalendar>	family()	Returns the associated calendar family.
HinduDay	getDayOfMonth()	Obtains the day of month.
Weekday	getDayOfWeek()	Determines the day of week.
int	getDayOfYear()	Obtains the day of year.
long	getDaysSinceEpochUTC()	Counts the elapsed days since UTC epoch.
HinduEra	getEra()	Obtains the era from the current Hindu variant.
HinduMonth	getMonth()	Obtains the month.
String	getVariant()	Yields the variant name of a calendar system.
int	getYear()	Obtains the year according to the current era and according to if the current Hindu variant uses elapsed years or current years.
int	hashCode()	Subclasses must redefine this method corresponding to the behaviour of equals().
static boolean	isValid(HinduVariant variant, HinduEra era, int yearOfEra, HinduMonth month, HinduDay dayOfMonth)	Queries if given parameter values form a well defined Hindu date before instantiating the date.
int	lengthOfMonth()	Yields the length of current Hindu month in days.
int	lengthOfYear()	Yields the length of current Hindu year in days.
HinduCalendar	nextDay()	Obtains the next day.
HinduCalendar	nextMonth()	Obtains the corresponding date of next month.
HinduCalendar	nextYear()	Obtains the corresponding date of next year.
static HinduCalendar	nowInSystemTime(HinduVariant variant)	Obtains the current calendar date in system time.
static HinduCalendar	nowInSystemTime(HinduVariant variant, StartOfDay startOfDay)	Obtains the current calendar date in system time.
static HinduCalendar	of(HinduVariant variant, HinduEra era, int yearOfEra, HinduMonth month, HinduDay dayOfMonth)	Creates an Hindu calendar with given components.
static HinduCalendar	ofOldLunar(int year, HinduMonth month, int dayOfMonth)	Creates an old lunisolar Hindu calendar with given components.
static HinduCalendar	ofOldSolar(int year, int month, int dayOfMonth)	Creates an old solar Hindu calendar with given components.
HinduCalendar	previousDay()	Obtains the previous day.
HinduCalendar	previousMonth()	Obtains the corresponding date of previous month.
HinduCalendar	previousYear()	Obtains the corresponding date of previous year.
String	toString()	Provides a complete textual representation of the state of this calendar variant.

Methods inherited from class net.time4j.engine.CalendarVariant

compareTo, isAfter, isBefore, isSimultaneous, minus, plus, withVariant, withVariant

Methods inherited from class net.time4j.engine.ChronoEntity

contains, get, get, getInt, getMaximum, getMinimum, getRegisteredElements, getTimezone, hasTimezone, isValid, isValid, isValid, matches, with, with, with, with

Methods inherited from class java.lang.Object

getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface net.time4j.engine.CalendarDate

transform, transform, transform, transform, transform, transform

Methods inherited from interface net.time4j.format.LocalizedPatternSupport

getFormatPattern, getFormatPattern, useDynamicFormatPattern

Methods inherited from interface net.time4j.engine.Temporal

isAfterAll, isAfterOrEqual, isBeforeAll, isBeforeOrEqual

Field Details

ERA

@FormattableElement(format="G")
public static final ChronoElement<HinduEra> ERA

Represents the Hindu era.

A change of the era by with() will not change the Hindu date in a temporal way but only the year representation. The changed era is stored in the variant of this calendar object. Attention: The old Hindu calendar ignores any era change and only supports Kali Yuga.

YEAR_OF_ERA

@FormattableElement(format="y")
public static final StdCalendarElement<Integer,HinduCalendar> YEAR_OF_ERA

Represents the Hindu year.

The range is for the era Kali Yuga defined by 0-5999 (elapsed year) resprective 1-6000 (current year) and will be adjusted accordingly for other eras. However, the modern Hindu calendar will use the year 1200 as minimum elapsed year.

MONTH_OF_YEAR

@FormattableElement(format="M")
public static final AdjustableTextElement<HinduMonth> MONTH_OF_YEAR

Represents the Hindu month.

The first lunar month should always be determined by with(MONTH_OF_YEAR.minimized()) because the first month in lunisolar context might be in leap state.

See Also:

ChronoEntity.getMinimum(ChronoElement), ChronoEntity.getMaximum(ChronoElement), ChronoEntity.with(ChronoOperator)

DAY_OF_MONTH

@FormattableElement(format="d")
public static final AdjustableTextElement<HinduDay> DAY_OF_MONTH

Represents the Hindu day of month.

The first day of lunar month should always be determined by with(DAY_OF_MONTH.minimized()) because the number of the first day of month in lunisolar context is not always 1. Similar thoughts also for the last day of lunar month.

See Also:

ChronoEntity.getMinimum(ChronoElement), ChronoEntity.getMaximum(ChronoElement), ChronoEntity.with(ChronoOperator)

DAY_OF_YEAR

@FormattableElement(format="D")
public static final StdCalendarElement<Integer,HinduCalendar> DAY_OF_YEAR

Represents the Hindu day of year.

New Year can be determined by with(DAY_OF_YEAR, 1) or with(DAY_OF_YEAR.minimized()).

DAY_OF_WEEK

@FormattableElement(format="E")
public static final StdCalendarElement<Weekday,HinduCalendar> DAY_OF_WEEK

Represents the Hindu day of week.

If the day-of-week is set to a new value then Time4J handles the Hindu calendar week as starting on Sunday.

Method Details

nowInSystemTime

public static HinduCalendar nowInSystemTime(HinduVariant variant)

Obtains the current calendar date in system time.

The time of sunrise in the holy city Ujjain is used as start of day.

Parameters:

variant - calendar variant

Returns:

current calendar date in system time zone using the system clock

See Also:

nowInSystemTime(HinduVariant, StartOfDay)

nowInSystemTime

public static HinduCalendar nowInSystemTime(HinduVariant variant,
 StartOfDay startOfDay)

Obtains the current calendar date in system time.

Convenient short-cut for: SystemClock.inLocalView().now(HinduCalendar.family(), variant, startOfDay).toDate()).

Parameters:

variant - calendar variant

startOfDay - determines the exact time of day when the calendar date will change (usually at sunrise)

Returns:

current calendar date in system time zone using the system clock

See Also:

SystemClock.inLocalView(), ZonalClock.now(CalendarFamily, VariantSource, StartOfDay)

ofOldSolar

public static HinduCalendar ofOldSolar(int year,
 int month,
 int dayOfMonth)

Creates an old solar Hindu calendar with given components.

The months use rasi numbers and start with VAISAKHA.

Parameters:

year - expired year of era Kali Yuga

month - month number (rasi numbering in range 1-12)

dayOfMonth - the day of given month in range 1-31

Returns:

HinduCalendar

Throws:

IllegalArgumentException - in case of any inconsistencies

See Also:

HinduMonth.getRasi(), AryaSiddhanta

ofOldLunar

public static HinduCalendar ofOldLunar(int year,
 HinduMonth month,
 int dayOfMonth)

Creates an old lunisolar Hindu calendar with given components.

The month CHAITRA is the first month of year.

Parameters:

year - expired year of era Kali Yuga

month - the Hindu month (possibly as leap month)

dayOfMonth - the day of given month

Returns:

HinduCalendar

Throws:

IllegalArgumentException - in case of any inconsistencies

See Also:

AryaSiddhanta

of

public static HinduCalendar of(HinduVariant variant,
 HinduEra era,
 int yearOfEra,
 HinduMonth month,
 HinduDay dayOfMonth)

Creates an Hindu calendar with given components.

Note: The modern variants of Hindu calendar use the year 1200 as miminum elapsed year.

Parameters:

variant - the variant of Hindu calendar

era - the desired era

yearOfEra - the year of given era (expired or current according to variant configuration)

month - the Hindu month (in lunisolar case possibly as leap month)

dayOfMonth - the day of given month (in lunisolar case possibly in leap state)

Returns:

HinduCalendar

Throws:

IllegalArgumentException - in case of any inconsistencies

isValid

public static boolean isValid(HinduVariant variant,
 HinduEra era,
 int yearOfEra,
 HinduMonth month,
 HinduDay dayOfMonth)

Queries if given parameter values form a well defined Hindu date before instantiating the date.

Example for a non-existing day:

    assertThat(
      HinduCalendar.isValid(
        AryaSiddhanta.LUNAR.variant(),
        HinduEra.KALI_YUGA,
        0,
        HinduMonth.of(IndianMonth.CHAITRA).withLeap(),
        HinduDay.valueOf(15)), // expunged day!
      is(false));
 

Parameters:

variant - the variant of Hindu calendar

era - the desired era

yearOfEra - the year of given era (expired or current according to variant configuration)

month - the Hindu month (in lunisolar case possibly as leap month)

dayOfMonth - the day of given month (in lunisolar case possibly in leap state)

Returns:

true if valid else false

See Also:

of(HinduVariant, HinduEra, int, HinduMonth, HinduDay), HinduRule.variant(), AryaSiddhanta.variant()

lengthOfMonth

public int lengthOfMonth()

Yields the length of current Hindu month in days.

Attention: This method obtains the real length while an expression like getMaximum(DAY_OF_MONTH).getValue() only shows the number of last day of month which can be different from the length of month - especially in a lunisolar context.

Returns:

int

lengthOfYear

public int lengthOfYear()

Yields the length of current Hindu year in days.

Returns:

int

getVariant

public String getVariant()

Description copied from interface: VariantSource

Yields the variant name of a calendar system.

Specified by:

getVariant in interface VariantSource

Returns:

String which is empty if there are no variants

getEra

public HinduEra getEra()

Obtains the era from the current Hindu variant.

If the associated (elapsed) year becomes negative then the method will fall back to Kali Yuga era.

Returns:

HinduEra

See Also:

ERA, HinduVariant.getDefaultEra()

getYear

public int getYear()

Obtains the year according to the current era and according to if the current Hindu variant uses elapsed years or current years.

Returns:

int

See Also:

YEAR_OF_ERA, getEra(), HinduEra.yearOfEra(HinduEra, int), HinduVariant.isUsingElapsedYears()

getMonth

public HinduMonth getMonth()

Obtains the month.

Returns:

HinduMonth

See Also:

MONTH_OF_YEAR

getDayOfMonth

public HinduDay getDayOfMonth()

Obtains the day of month.

Returns:

HinduDay

See Also:

DAY_OF_MONTH, withFirstDayOfMonth()

getDayOfWeek

public Weekday getDayOfWeek()

Determines the day of week.

Returns:

Weekday

See Also:

DAY_OF_WEEK

getDayOfYear

public int getDayOfYear()

Obtains the day of year.

Returns:

int

See Also:

DAY_OF_YEAR, withNewYear()

previousDay

public HinduCalendar previousDay()

Obtains the previous day.

Returns:

HinduCalendar

Throws:

IllegalArgumentException - if the adjusted date is out of range

previousMonth

public HinduCalendar previousMonth()

Obtains the corresponding date of previous month.

Returns:

HinduCalendar

Throws:

IllegalArgumentException - if the adjusted date is out of range

previousYear

public HinduCalendar previousYear()

Obtains the corresponding date of previous year.

Returns:

HinduCalendar

Throws:

IllegalArgumentException - if the adjusted date is out of range

nextDay

public HinduCalendar nextDay()

Obtains the next day.

Returns:

HinduCalendar

Throws:

IllegalArgumentException - if the adjusted date is out of range

nextMonth

public HinduCalendar nextMonth()

Obtains the corresponding date of next month.

Returns:

HinduCalendar

Throws:

IllegalArgumentException - if the adjusted date is out of range

nextYear

public HinduCalendar nextYear()

Obtains the corresponding date of next year.

Returns:

HinduCalendar

Throws:

IllegalArgumentException - if the adjusted date is out of range

at

public GeneralTimestamp<HinduCalendar> at(PlainTime time)

Creates a new local timestamp with this date and given civil time.

If the time T24:00 is used then the resulting timestamp will automatically be normalized such that the timestamp will contain the following day instead.

Parameters:

time - wall time

Returns:

general timestamp as composition of this date and given time

atTime

public GeneralTimestamp<HinduCalendar> atTime(int hour,
 int minute)

Is equivalent to at(PlainTime.of(hour, minute)).

Parameters:

hour - hour of day in range (0-24)

minute - minute of hour in range (0-59)

Returns:

general timestamp as composition of this date and given time

Throws:

IllegalArgumentException - if any argument is out of range

See Also:

at(PlainTime)

equals

public boolean equals(Object obj)

Description copied from class: CalendarVariant

Compares the whole state of this instance with given object.

Implementations will usually define their state based on the temporal position and the variant name. Exceptions from this rule should be explicitly documented and reasoned.

Specified by:

equals in class CalendarVariant<HinduCalendar>

See Also:

CalendarVariant.compareTo(CalendarVariant)

hashCode

public int hashCode()

Description copied from class: CalendarVariant

Subclasses must redefine this method corresponding to the behaviour of equals().

Specified by:

hashCode in class CalendarVariant<HinduCalendar>

toString

public String toString()

Description copied from class: CalendarVariant

Provides a complete textual representation of the state of this calendar variant.

Specified by:

toString in class CalendarVariant<HinduCalendar>

getDaysSinceEpochUTC

public long getDaysSinceEpochUTC()

Description copied from interface: CalendarDate

Counts the elapsed days since UTC epoch.

Specified by:

getDaysSinceEpochUTC in interface CalendarDate

Overrides:

getDaysSinceEpochUTC in class CalendarVariant<HinduCalendar>

Returns:

count of days relative to UTC epoch [1972-01-01]

See Also:

EpochDays.UTC

family

public static CalendarFamily<HinduCalendar> family()

Returns the associated calendar family.

Returns:

chronology as calendar family