JapaneseCalendar

public class JapaneseCalendar
extends GregorianCalendar

java.lang.Object
   ↳ android.icu.util.Calendar
     ↳ android.icu.util.GregorianCalendar
       ↳ android.icu.util.JapaneseCalendar


JapaneseCalendar is a subclass of GregorianCalendar that numbers years and eras based on the reigns of the Japanese emperors. The Japanese calendar is identical to the Gregorian calendar in all respects except for the year and era. The ascension of each emperor to the throne begins a new era, and the years of that era are numbered starting with the year of ascension as year 1.

Note that in the year of an imperial ascension, there are two possible sets of year and era values: that for the old era and for the new. For example, a new era began on January 7, 1989 AD. Strictly speaking, the first six days of that year were in the Showa era, e.g. "January 6, 64 Showa", while the rest of the year was in the Heisei era, e.g. "January 7, 1 Heisei". This class handles this distinction correctly when computing dates. However, in lenient mode either form of date is acceptable as input.

In modern times, eras have started on January 8, 1868 AD, Gregorian (Meiji), July 30, 1912 (Taisho), December 25, 1926 (Showa), and January 7, 1989 (Heisei). Constants for these eras, suitable for use in the ERA field, are provided in this class. Note that the number used for each era is more or less arbitrary. Currently, the era starting in 645 AD is era #0; however this may change in the future. Use the predefined constants rather than using actual, absolute numbers.

Since ICU4J 63, start date of each era is imported from CLDR. CLDR era data may contain tentative era in near future with placeholder names. By default, such era data is not enabled. ICU4J users who want to test the behavior of the future era can enable this by one of following settings (in the priority order):

  1. Java system property ICU_ENABLE_TENTATIVE_ERA=true.
  2. Environment variable ICU_ENABLE_TENTATIVE_ERA=true.
  3. Java system property jdk.calendar.japanese.supplemental.era=xxx. (Note: This configuration is used for specifying a new era's start date and names in OpenJDK. ICU4J implementation enables the CLDR tentative era when this property is defined, but it does not use the start date and names specified by the property value.)

This class should not be subclassed.

JapaneseCalendar usually should be instantiated using Calendar.getInstance(ULocale) passing in a ULocale with the tag "@calendar=japanese".

Summary

Inherited constants

Fields

public static final int HEISEI

Constant for the era starting on Jan.

public static final int MEIJI

Constant for the era starting on Sept.

public static final int REIWA

Constant for the era starting on May 1, 2019 AD.

public static final int SHOWA

Constant for the era starting on Dec.

public static final int TAISHO

Constant for the era starting on July 30, 1912 AD.

Inherited fields

Public constructors

JapaneseCalendar()

Constructs a default JapaneseCalendar using the current time in the default time zone with the default locale.

JapaneseCalendar(TimeZone zone)

Constructs a JapaneseCalendar based on the current time in the given time zone with the default locale.

JapaneseCalendar(Locale aLocale)

Constructs a JapaneseCalendar based on the current time in the default time zone with the given locale.

JapaneseCalendar(ULocale locale)

Constructs a JapaneseCalendar based on the current time in the default time zone with the given locale.

JapaneseCalendar(TimeZone zone, Locale aLocale)

Constructs a JapaneseCalendar based on the current time in the given time zone with the given locale.

JapaneseCalendar(TimeZone zone, ULocale locale)

Constructs a JapaneseCalendar based on the current time in the given time zone with the given locale.

JapaneseCalendar(Date date)

Constructs a JapaneseCalendar with the given date set in the default time zone with the default locale.

JapaneseCalendar(int era, int year, int month, int date)

Constructs a JapaneseCalendar with the given date set in the default time zone with the default locale.

JapaneseCalendar(int year, int month, int date)

Constructs a JapaneseCalendar with the given date set in the default time zone with the default locale.

JapaneseCalendar(int year, int month, int date, int hour, int minute, int second)

Constructs a JapaneseCalendar with the given date and time set for the default time zone with the default locale.

Public methods

int getActualMaximum(int field)

Return the maximum value that this field could have, given the current date.

String getType()

[icu] Returns the calendar type name string for this Calendar object.

Protected methods

void handleComputeFields(int julianDay)

Override Calendar to compute several fields specific to the hybrid Gregorian-Julian calendar system.

int handleGetExtendedYear()

Returns the extended year defined by the current fields.

int handleGetLimit(int field, int limitType)

Override GregorianCalendar.

Inherited methods

Fields

HEISEI

Added in API level 24
public static final int HEISEI

Constant for the era starting on Jan. 7, 1989 AD.

MEIJI

Added in API level 24
public static final int MEIJI

Constant for the era starting on Sept. 8, 1868 AD.

REIWA

Added in API level 30
public static final int REIWA

Constant for the era starting on May 1, 2019 AD.

SHOWA

Added in API level 24
public static final int SHOWA

Constant for the era starting on Dec. 25, 1926 AD.

TAISHO

Added in API level 24
public static final int TAISHO

Constant for the era starting on July 30, 1912 AD.

Public constructors

JapaneseCalendar

Added in API level 24
public JapaneseCalendar ()

Constructs a default JapaneseCalendar using the current time in the default time zone with the default locale.

JapaneseCalendar

Added in API level 24
public JapaneseCalendar (TimeZone zone)

Constructs a JapaneseCalendar based on the current time in the given time zone with the default locale.

Parameters
zone TimeZone: the given time zone.

JapaneseCalendar

Added in API level 24
public JapaneseCalendar (Locale aLocale)

Constructs a JapaneseCalendar based on the current time in the default time zone with the given locale.

Parameters
aLocale Locale: the given locale.

JapaneseCalendar

Added in API level 24
public JapaneseCalendar (ULocale locale)

Constructs a JapaneseCalendar based on the current time in the default time zone with the given locale.

Parameters
locale ULocale: the given ulocale.

JapaneseCalendar

Added in API level 24
public JapaneseCalendar (TimeZone zone, 
                Locale aLocale)

Constructs a JapaneseCalendar based on the current time in the given time zone with the given locale.

Parameters
zone TimeZone: the given time zone.

aLocale Locale: the given locale.

JapaneseCalendar

Added in API level 24
public JapaneseCalendar (TimeZone zone, 
                ULocale locale)

Constructs a JapaneseCalendar based on the current time in the given time zone with the given locale.

Parameters
zone TimeZone: the given time zone.

locale ULocale: the given ulocale.

JapaneseCalendar

Added in API level 24
public JapaneseCalendar (Date date)

Constructs a JapaneseCalendar with the given date set in the default time zone with the default locale.

Parameters
date Date: The date to which the new calendar is set.

JapaneseCalendar

Added in API level 24
public JapaneseCalendar (int era, 
                int year, 
                int month, 
                int date)

Constructs a JapaneseCalendar with the given date set in the default time zone with the default locale.

Parameters
era int: The imperial era used to set the calendar's ERA field. Eras are numbered starting with the Tenki era, which began in 1053 AD Gregorian, as era zero. Recent eras can be specified using the constants MEIJI (which started in 1868 AD), TAISHO (1912 AD), SHOWA (1926 AD), and HEISEI (1989 AD).

year int: The value used to set the calendar's YEAR field, in terms of the era.

month int: The value used to set the calendar's MONTH field. The value is 0-based. e.g., 0 for January.

date int: The value used to set the calendar's DATE field.

JapaneseCalendar

Added in API level 24
public JapaneseCalendar (int year, 
                int month, 
                int date)

Constructs a JapaneseCalendar with the given date set in the default time zone with the default locale.

Parameters
year int: The value used to set the calendar's YEAR field, in the era Heisei, the most current at the time this class was last updated.

month int: The value used to set the calendar's MONTH field. The value is 0-based. e.g., 0 for January.

date int: The value used to set the calendar's DATE field.

JapaneseCalendar

Added in API level 24
public JapaneseCalendar (int year, 
                int month, 
                int date, 
                int hour, 
                int minute, 
                int second)

Constructs a JapaneseCalendar with the given date and time set for the default time zone with the default locale.

Parameters
year int: The value used to set the calendar's YEAR time field, in the era Heisei, the most current at the time of this writing.

month int: The value used to set the calendar's MONTH time field. The value is 0-based. e.g., 0 for January.

date int: The value used to set the calendar's DATE time field.

hour int: The value used to set the calendar's HOUR_OF_DAY time field.

minute int: The value used to set the calendar's MINUTE time field.

second int: The value used to set the calendar's SECOND time field.

Public methods

getActualMaximum

Added in API level 24
public int getActualMaximum (int field)

Return the maximum value that this field could have, given the current date. For example, with the date "Feb 3, 1997" and the DAY_OF_MONTH field, the actual maximum would be 28; for "Feb 3, 1996" it s 29. Similarly for a Hebrew calendar, for some years the actual maximum for MONTH is 12, and for others 13.

Parameters
field int: the field whose maximum is desired

Returns
int the maximum of the given field for the current date of this calendar

getType

Added in API level 24
public String getType ()

[icu] Returns the calendar type name string for this Calendar object. The returned string is the legacy ICU calendar attribute value, for example, "gregorian" or "japanese".

See type="old type name" for the calendar attribute of locale IDs at http://www.unicode.org/reports/tr35/#Key_Type_Definitions

Returns
String legacy calendar type name string

Protected methods

handleComputeFields

Added in API level 24
protected void handleComputeFields (int julianDay)

Override Calendar to compute several fields specific to the hybrid Gregorian-Julian calendar system. These are:

  • ERA
  • YEAR
  • MONTH
  • DAY_OF_MONTH
  • DAY_OF_YEAR
  • EXTENDED_YEAR

Parameters
julianDay int

handleGetExtendedYear

Added in API level 24
protected int handleGetExtendedYear ()

Returns the extended year defined by the current fields. This will use the EXTENDED_YEAR field or the YEAR and supra-year fields (such as ERA) specific to the calendar system, depending on which set of fields is newer.

Returns
int the extended year

handleGetLimit

Added in API level 24
protected int handleGetLimit (int field, 
                int limitType)

Override GregorianCalendar. We should really handle YEAR_WOY and EXTENDED_YEAR here too to implement the 1..5000000 range, but it's not critical.

Parameters
field int: one of the above field numbers

limitType int: one of MINIMUM, GREATEST_MINIMUM, LEAST_MAXIMUM, or MAXIMUM

Returns
int