net.time4j.calendar

Class VietnameseCalendar

java.lang.Object

net.time4j.engine.ChronoEntity<T>

net.time4j.engine.TimePoint<U,D>

net.time4j.engine.Calendrical<U,D>

net.time4j.calendar.EastAsianCalendar<VietnameseCalendar.Unit,VietnameseCalendar>

net.time4j.calendar.VietnameseCalendar

All Implemented Interfaces:

Serializable, Comparable<VietnameseCalendar>, CalendarDate, ChronoDisplay, Temporal<CalendarDate>, LocalizedPatternSupport

@CalendarType(value="vietnam")
public final class VietnameseCalendar
extends EastAsianCalendar<VietnameseCalendar.Unit,VietnameseCalendar>
implements LocalizedPatternSupport

Represents the Vietnamese calendar supported in the gregorian range 1813-02-01/3000-01-27.

Introduction

It is a lunisolar calendar which is supposed to be structurally identical to the Chinese calendar. See also the page of Ho Ngoc Duc. The historic details of the calendar rules before 1954 are somehow debatable. Probably different authorities or institutions in Vietnam used slightly different versions of Chinese calendar. Time4J follows the rules described on Wikipedia.

• 1813–1840: It was essentially the Shíxiàn calendar introduced by the Chinese Qing dynasty to the Vietnamese Nguyễn dynasty.
• 1841-1954: Hiệp-kỷ-calendar began to differ from Shíxiàn due to longitudinal differences between Vietnam and China.
• 1955-1967: UTC+8 is used for calendar calculations.
• since 1968: UTC+7 is used (first in North Vietnam, since reunification in 1975 also in Southern part).

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

• DAY_OF_WEEK
• DAY_OF_MONTH
• DAY_OF_YEAR
• WEEKDAY_IN_MONTH
• MONTH_OF_YEAR
• MONTH_AS_ORDINAL
• SOLAR_TERM
• YEAR_OF_CYCLE
• CYCLE

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

Example of usage

     ChronoFormatter<VietnameseCalendar> formatter =
       ChronoFormatter.setUp(VietnameseCalendar.axis(), Locale.ENGLISH)
       .addPattern("EEE, d. MMMM U(r)", PatternType.CLDR_DATE).build();
     PlainDate today = SystemClock.inLocalView().today();
     VietnameseCalendar vietDate = today.transform(VietnameseCalendar.class);
     System.out.println(formatter.format(vietDate));
 

Support for unicode ca-extensions

      Locale locale = Locale.forLanguageTag("en-u-ca-vietnam");
      ChronoFormatter<CalendarDate> f = ChronoFormatter.ofGenericCalendarStyle(DisplayMode.FULL, locale);
      assertThat(
          f.format(PlainDate.of(2017, 10, 1)),
          is("Sunday, Eighth Month 12, 2017(dīng-yǒu)"));
 

Since:

3.40/4.35

Author:

Meno Hochschild

See Also:

ChineseCalendar, Serialized Form

Concurrency:

This class is immutable and can be used by multiple threads in parallel.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	VietnameseCalendar.Unit Defines some calendar units for the Vietnamese calendar.

Field Summary

Fields

Modifier and Type	Field and Description
static ChronoElement<Integer>	CYCLE Represents the cycle number related to the introduction of sexagesimal cycles by the legendary Chinese yellow emperor Huang-Di on -2636-02-15 (gregorian).
static StdCalendarElement<Integer,VietnameseCalendar>	DAY_OF_MONTH Represents the Vietnamese day of month.
static StdCalendarElement<Weekday,VietnameseCalendar>	DAY_OF_WEEK Represents the Vietnamese day of week.
static StdCalendarElement<Integer,VietnameseCalendar>	DAY_OF_YEAR Represents the Vietnamese day of year.
static StdCalendarElement<Integer,VietnameseCalendar>	MONTH_AS_ORDINAL Represents the ordinal index of a Vietnamese month in the range 1-12/13.
static TextElement<EastAsianMonth>	MONTH_OF_YEAR Represents the Vietnamese month.
static ChronoElement<SolarTerm>	SOLAR_TERM Represents the solar term as one of 24 possible stations of the sun on the ecliptic.
static OrdinalWeekdayElement<VietnameseCalendar>	WEEKDAY_IN_MONTH Element with the ordinal day-of-week within given calendar month.
static TextElement<CyclicYear>	YEAR_OF_CYCLE Represents the Vietnamese year related to the current sexagesimal cycle.

Method Summary

Modifier and Type	Method and Description
static TimeAxis<VietnameseCalendar.Unit,VietnameseCalendar>	axis() Returns the associated time axis.
static Weekmodel	getDefaultWeekmodel() Obtains the standard week model of this calendar.
static boolean	isValid(EastAsianYear year, EastAsianMonth month, int dayOfMonth) Queries if given parameter values form a well defined calendar date.
static VietnameseCalendar	nowInSystemTime() Obtains the current calendar date in system time.
static VietnameseCalendar	of(EastAsianYear year, EastAsianMonth month, int dayOfMonth) Creates a new instance of a Vietnamese calendar date.
static VietnameseCalendar	ofTet(int gregorianYear) Creates a new instance of a Vietnamese calendar date on New Year (Tet).

Methods inherited from class net.time4j.calendar.EastAsianCalendar

at, atTime, equals, findLeapMonth, getDayOfMonth, getDayOfWeek, getDayOfYear, getDaysSinceEpochUTC, getMonth, getSexagesimalDay, getSexagesimalMonth, getSolarTerm, getYear, hashCode, isLeapYear, lengthOfMonth, lengthOfYear, toString, withBeginOfNextLeapMonth

Methods inherited from class net.time4j.engine.Calendrical

compareTo, isAfter, isBefore, isSimultaneous, minus, plus

Methods inherited from class net.time4j.engine.TimePoint

max, min, minus, minus, plus, plus, until, until

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.format.LocalizedPatternSupport

getFormatPattern, getFormatPattern, useDynamicFormatPattern

Methods inherited from interface net.time4j.engine.CalendarDate

from, from, from, transform, transform, transform, transform, transform, transform

Methods inherited from interface net.time4j.engine.Temporal

isAfterAll, isAfterOrEqual, isBeforeAll, isBeforeOrEqual

Field Detail

CYCLE

public static final ChronoElement<Integer> CYCLE

Represents the cycle number related to the introduction of sexagesimal cycles by the legendary Chinese yellow emperor Huang-Di on -2636-02-15 (gregorian).

This kind of counting is NOT in common use in Vietnam and only offered for technical reasons. Prefer just the cyclic year together with the related gregorian year instead.

See Also:

YEAR_OF_CYCLE, CommonElements.RELATED_GREGORIAN_YEAR

YEAR_OF_CYCLE

@FormattableElement(format="U")
public static final TextElement<CyclicYear> YEAR_OF_CYCLE

Represents the Vietnamese year related to the current sexagesimal cycle.

SOLAR_TERM

public static final ChronoElement<SolarTerm> SOLAR_TERM

Represents the solar term as one of 24 possible stations of the sun on the ecliptic.

See Also:

ChineseCalendar.SOLAR_TERM

MONTH_OF_YEAR

@FormattableElement(format="M",
                    alt="L")
public static final TextElement<EastAsianMonth> MONTH_OF_YEAR

Represents the Vietnamese month.

MONTH_AS_ORDINAL

public static final StdCalendarElement<Integer,VietnameseCalendar> MONTH_AS_ORDINAL

Represents the ordinal index of a Vietnamese month in the range 1-12/13.

This element can be used in conjunction with ordinal formatting.

DAY_OF_MONTH

@FormattableElement(format="d")
public static final StdCalendarElement<Integer,VietnameseCalendar> DAY_OF_MONTH

Represents the Vietnamese day of month.

Months have either 29 or 30 days.

DAY_OF_YEAR

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

Represents the Vietnamese day of year.

DAY_OF_WEEK

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

Represents the Vietnamese day of week.

If the day-of-week is set to a new value then Time4J handles the Chinese calendar week as starting on Monday (like in modern Vietnam).

See Also:

getDefaultWeekmodel(), CommonElements.localDayOfWeek(Chronology, Weekmodel)

WEEKDAY_IN_MONTH

@FormattableElement(format="F")
public static final OrdinalWeekdayElement<VietnameseCalendar> WEEKDAY_IN_MONTH

Element with the ordinal day-of-week within given calendar month.

Method Detail

ofTet

public static VietnameseCalendar ofTet(int gregorianYear)

Creates a new instance of a Vietnamese calendar date on New Year (Tet).

Parameters:

gregorianYear - gregorian calendar year

Returns:

new instance of VietnameseCalendar

Throws:

IllegalArgumentException - in case of any inconsistencies

of

public static VietnameseCalendar of(EastAsianYear year,
                                    EastAsianMonth month,
                                    int dayOfMonth)

Creates a new instance of a Vietnamese calendar date.

Parameters:

year - references the year using sexagesimal cycles

month - the month which might be a leap month

dayOfMonth - the day of month to be checked

Returns:

new instance of ChineseCalendar

Throws:

IllegalArgumentException - in case of any inconsistencies

nowInSystemTime

public static VietnameseCalendar nowInSystemTime()

Obtains the current calendar date in system time.

Convenient short-cut for: SystemClock.inLocalView().now(VietnameseCalendar.axis()).

Returns:

current calendar date in system time zone using the system clock

See Also:

SystemClock.inLocalView(), ZonalClock.now(Chronology)

isValid

public static boolean isValid(EastAsianYear year,
                              EastAsianMonth month,
                              int dayOfMonth)

Queries if given parameter values form a well defined calendar date.

Parameters:

year - the year to be checked

month - the month to be checked

dayOfMonth - the day of month to be checked

Returns:

true if valid else false

getDefaultWeekmodel

public static Weekmodel getDefaultWeekmodel()

Obtains the standard week model of this calendar.

The modern Vietnamese calendar usually starts on Monday.

Returns:

Weekmodel

axis

public static TimeAxis<VietnameseCalendar.Unit,VietnameseCalendar> axis()

Returns the associated time axis.

Returns:

chronology