Added in API level 26

JapaneseDate

class JapaneseDate : ChronoLocalDate, Serializable, Temporal, TemporalAdjuster

A date in the Japanese Imperial calendar system.

This date operates using the Japanese Imperial calendar. This calendar system is primarily used in Japan.

The Japanese Imperial calendar system is the same as the ISO calendar system apart from the era-based year numbering. The proleptic-year is defined to be equal to the ISO proleptic-year.

Japan introduced the Gregorian calendar starting with Meiji 6. Only Meiji and later eras are supported; dates before Meiji 6, January 1 are not supported.

For example, the Japanese year "Heisei 24" corresponds to ISO year "2012".
Calling japaneseDate.get(YEAR_OF_ERA) will return 24.
Calling japaneseDate.get(YEAR) will return 2012.
Calling japaneseDate.get(ERA) will return 2, corresponding to JapaneseChronology.ERA_HEISEI.

Summary

Public methods
ChronoLocalDateTime<JapaneseDate!>!
atTime(localTime: LocalTime!)

Boolean
equals(other: Any?)

Compares this date to another date, including the chronology.

static JapaneseDate!
from(temporal: TemporalAccessor!)

Obtains a JapaneseDate from a temporal object.

JapaneseChronology!

Gets the chronology of this date, which is the Japanese calendar system.

JapaneseEra!

Gets the era applicable at this date.

Long

Int

A hash code for this date.

Boolean

Checks if the specified field is supported.

Int

Returns the length of the month represented by this date.

Int

JapaneseDate!

Returns an object of the same type as this object with an amount subtracted.

JapaneseDate!
minus(amountToAdd: Long, unit: TemporalUnit!)

static JapaneseDate!
now()

Obtains the current JapaneseDate from the system clock in the default time-zone.

static JapaneseDate!
now(clock: Clock!)

Obtains the current JapaneseDate from the specified clock.

static JapaneseDate!
now(zone: ZoneId!)

Obtains the current JapaneseDate from the system clock in the specified time-zone.

static JapaneseDate!
of(prolepticYear: Int, month: Int, dayOfMonth: Int)

Obtains a JapaneseDate representing a date in the Japanese calendar system from the proleptic-year, month-of-year and day-of-month fields.

static JapaneseDate!
of(era: JapaneseEra!, yearOfEra: Int, month: Int, dayOfMonth: Int)

Obtains a JapaneseDate representing a date in the Japanese calendar system from the era, year-of-era, month-of-year and day-of-month fields.

JapaneseDate!
plus(amount: TemporalAmount!)

Returns an object of the same type as this object with an amount added.

JapaneseDate!
plus(amountToAdd: Long, unit: TemporalUnit!)

ValueRange!

Long

String

ChronoPeriod!

Long
until(endExclusive: Temporal!, unit: TemporalUnit!)

JapaneseDate!
with(adjuster: TemporalAdjuster!)

Returns an adjusted object of the same type as this object with the adjustment made.

JapaneseDate!
with(field: TemporalField!, newValue: Long)

Inherited functions
Temporal! adjustInto(temporal: Temporal!)

Adjusts the specified temporal object to have the same date as this object.

This returns a temporal object of the same observable type as the input with the date changed to be the same as this.

The adjustment is equivalent to using Temporal.with(TemporalField, long) passing ChronoField.EPOCH_DAY as the field.

In most cases, it is clearer to reverse the calling pattern by using Temporal.with(TemporalAdjuster):

// these two lines are equivalent, but the second approach is recommended
    temporal = thisLocalDate.adjustInto(temporal);
    temporal = temporal.with(thisLocalDate);
  

This instance is immutable and unaffected by this method call.

Int compareTo(other: ChronoLocalDate!)

Compares this date to another date, including the chronology.

The comparison is based first on the underlying time-line date, then on the chronology. It is "consistent with equals", as defined by Comparable.

For example, the following is the comparator order:

  1. 2012-12-03 (ISO)
  2. 2012-12-04 (ISO)
  3. 2555-12-04 (ThaiBuddhist)
  4. 2012-12-05 (ISO)
Values #2 and #3 represent the same date on the time-line. When two values represent the same date, the chronology ID is compared to distinguish them. This step is needed to make the ordering "consistent with equals".

If all the date objects being compared are in the same chronology, then the additional chronology stage is not required and only the local date is used. To compare the dates of two TemporalAccessor instances, including dates in two different chronologies, use ChronoField.EPOCH_DAY as a comparator.

This default implementation performs the comparison defined above.

String! format(formatter: DateTimeFormatter!)

Formats this date using the specified formatter.

This date will be passed to the formatter to produce a string.

The default implementation must behave as follows:

return formatter.format(this);
  

Boolean isAfter(other: ChronoLocalDate!)

Checks if this date is after the specified date ignoring the chronology.

This method differs from the comparison in compareTo in that it only compares the underlying date and not the chronology. This allows dates in different calendar systems to be compared based on the time-line position. This is equivalent to using date1.toEpochDay() > date2.toEpochDay().

This default implementation performs the comparison based on the epoch-day.

Boolean isBefore(other: ChronoLocalDate!)

Checks if this date is before the specified date ignoring the chronology.

This method differs from the comparison in compareTo in that it only compares the underlying date and not the chronology. This allows dates in different calendar systems to be compared based on the time-line position. This is equivalent to using date1.toEpochDay() < date2.toEpochDay().

This default implementation performs the comparison based on the epoch-day.

Boolean isEqual(other: ChronoLocalDate!)

Checks if this date is equal to the specified date ignoring the chronology.

This method differs from the comparison in compareTo in that it only compares the underlying date and not the chronology. This allows dates in different calendar systems to be compared based on the time-line position. This is equivalent to using date1.toEpochDay() == date2.toEpochDay().

This default implementation performs the comparison based on the epoch-day.

Boolean isLeapYear()

Checks if the year is a leap year, as defined by the calendar system.

A leap-year is a year of a longer length than normal. The exact meaning is determined by the chronology with the constraint that a leap-year must imply a year-length longer than a non leap-year.

This default implementation uses Chronology.isLeapYear(long).

Boolean isSupported(unit: TemporalUnit!)

Checks if the specified unit is supported.

This checks if the specified unit can be added to or subtracted from this date. If false, then calling the plus(long,java.time.temporal.TemporalUnit) and minus methods will throw an exception.

The set of supported units is defined by the chronology and normally includes all ChronoUnit date units except FOREVER.

If the unit is not a ChronoUnit, then the result of this method is obtained by invoking TemporalUnit.isSupportedBy(Temporal) passing this as the argument. Whether the unit is supported is determined by the unit.

R query(query: TemporalQuery<R>!)

Queries this date using the specified query.

This queries this date using the specified query strategy object. The TemporalQuery object defines the logic to be used to obtain the result. Read the documentation of the query to understand what the result of this method will be.

The result of this method is obtained by invoking the TemporalQuery.queryFrom(TemporalAccessor) method on the specified query passing this as the argument.

Public methods

atTime

Added in API level 26
fun atTime(localTime: LocalTime!): ChronoLocalDateTime<JapaneseDate!>!
Parameters
localTime LocalTime!: the local time to use, not null
Return
ChronoLocalDateTime<JapaneseDate!>! the local date-time formed from this date and the specified time, not null

equals

Added in API level 26
fun equals(other: Any?): Boolean

Compares this date to another date, including the chronology.

Compares this JapaneseDate with another ensuring that the date is the same.

Only objects of type JapaneseDate 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.

Parameters
obj the object to check, null returns false
Return
Boolean true if this is equal to the other date

from

Added in API level 26
static fun from(temporal: TemporalAccessor!): JapaneseDate!

Obtains a JapaneseDate from a temporal object.

This obtains a date in the Japanese 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 JapaneseDate.

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, JapaneseDate::from.

Parameters
temporal TemporalAccessor!: the temporal object to convert, not null
Return
JapaneseDate! the date in Japanese calendar system, not null
Exceptions
java.time.DateTimeException if unable to convert to a JapaneseDate

getChronology

Added in API level 26
fun getChronology(): JapaneseChronology!

Gets the chronology of this date, which is the Japanese calendar system.

The Chronology represents the calendar system in use. The era and other fields in ChronoField are defined by the chronology.

Return
JapaneseChronology! the Japanese chronology, not null

getEra

Added in API level 26
fun getEra(): JapaneseEra!

Gets the era applicable at this date.

The Japanese calendar system has multiple eras defined by JapaneseEra.

Return
JapaneseEra! the era applicable at this date, not null

getLong

Added in API level 26
fun getLong(field: TemporalField!): Long
Parameters
field TemporalField!: the field to get, not null
Return
Long the value for the field
Exceptions
java.time.DateTimeException if a value for the field cannot be obtained
java.time.temporal.UnsupportedTemporalTypeException if the field is not supported
java.lang.ArithmeticException if numeric overflow occurs

hashCode

Added in API level 26
fun hashCode(): Int

A hash code for this date.

Return
Int a suitable hash code based only on the Chronology and the date

isSupported

Added in API level 26
fun isSupported(field: TemporalField!): Boolean

Checks if the specified field is supported.

This checks if this date can be queried for the specified field. If false, then calling the range and get methods will throw an exception.

If the field is a ChronoField then the query is implemented here. The supported fields are:

  • DAY_OF_WEEK
  • DAY_OF_MONTH
  • DAY_OF_YEAR
  • EPOCH_DAY
  • MONTH_OF_YEAR
  • PROLEPTIC_MONTH
  • YEAR_OF_ERA
  • YEAR
  • ERA
All other ChronoField instances will return false.

If the field is not a ChronoField, then the result of this method is obtained by invoking TemporalField.isSupportedBy(TemporalAccessor) passing this as the argument. Whether the field is supported is determined by the field.

Parameters
field TemporalField!: the field to check, null returns false
Return
Boolean true if the field is supported on this date, false if not

lengthOfMonth

Added in API level 26
fun lengthOfMonth(): Int

Returns the length of the month represented by this date.

This returns the length of the month in days. Month lengths match those of the ISO calendar system.

Return
Int the length of the month in days

lengthOfYear

Added in API level 26
fun lengthOfYear(): Int
Return
Int the length of the year in days

minus

Added in API level 26
fun minus(amount: TemporalAmount!): JapaneseDate!

Returns an object of the same type as this object with an amount subtracted.

This adjusts this temporal, subtracting according to the rules of the specified amount. The amount is typically a java.time.Period but may be any other type implementing the TemporalAmount interface, such as java.time.Duration.

Some example code indicating how and why this method is used:

date = date.minus(period);               // subtract a Period instance
   date = date.minus(duration);             // subtract a Duration instance
   date = date.minus(workingDays(6));       // example user-written workingDays method
  

Note that calling plus followed by minus is not guaranteed to return the same date-time.

Parameters
amount TemporalAmount!: the amount to subtract, not null
Return
JapaneseDate! an object of the same type with the specified adjustment made, not null
Exceptions
java.time.DateTimeException if the subtraction cannot be made
java.lang.ArithmeticException if numeric overflow occurs

minus

Added in API level 26
fun minus(
    amountToAdd: Long,
    unit: TemporalUnit!
): JapaneseDate!
Parameters
amountToSubtract the amount of the specified unit to subtract, may be negative
unit TemporalUnit!: the unit of the amount to subtract, not null
Return
JapaneseDate! an object of the same type with the specified period subtracted, not null
Exceptions
java.time.DateTimeException if the unit cannot be subtracted
java.time.temporal.UnsupportedTemporalTypeException if the unit is not supported
java.lang.ArithmeticException if numeric overflow occurs

now

Added in API level 26
static fun now(): JapaneseDate!

Obtains the current JapaneseDate from the system clock 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.

Return
JapaneseDate! the current date using the system clock and default time-zone, not null

now

Added in API level 26
static fun now(clock: Clock!): JapaneseDate!

Obtains the current JapaneseDate 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.

Parameters
clock Clock!: the clock to use, not null
Return
JapaneseDate! the current date, not null
Exceptions
java.time.DateTimeException if the current date cannot be obtained

now

Added in API level 26
static fun now(zone: ZoneId!): JapaneseDate!

Obtains the current JapaneseDate from the system clock 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.

Parameters
zone ZoneId!: the zone ID to use, not null
Return
JapaneseDate! the current date using the system clock, not null

of

Added in API level 26
static fun of(
    prolepticYear: Int,
    month: Int,
    dayOfMonth: Int
): JapaneseDate!

Obtains a JapaneseDate representing a date in the Japanese calendar system from the proleptic-year, month-of-year and day-of-month fields.

This returns a JapaneseDate with the specified fields. The day must be valid for the year and month, otherwise an exception will be thrown.

The Japanese proleptic year, month and day-of-month are the same as those in the ISO calendar system. They are not reset when the era changes.

Parameters
prolepticYear Int: the Japanese proleptic-year
month Int: the Japanese month-of-year, from 1 to 12
dayOfMonth Int: the Japanese day-of-month, from 1 to 31
Return
JapaneseDate! the date in Japanese calendar system, not null
Exceptions
java.time.DateTimeException if the value of any field is out of range, or if the day-of-month is invalid for the month-year

of

Added in API level 26
static fun of(
    era: JapaneseEra!,
    yearOfEra: Int,
    month: Int,
    dayOfMonth: Int
): JapaneseDate!

Obtains a JapaneseDate representing a date in the Japanese calendar system from the era, year-of-era, month-of-year and day-of-month fields.

This returns a JapaneseDate with the specified fields. The day must be valid for the year and month, otherwise an exception will be thrown.

The Japanese month and day-of-month are the same as those in the ISO calendar system. They are not reset when the era changes. For example:

6th Jan Showa 64 = ISO 1989-01-06
   7th Jan Showa 64 = ISO 1989-01-07
   8th Jan Heisei 1 = ISO 1989-01-08
   9th Jan Heisei 1 = ISO 1989-01-09
  
Parameters
era JapaneseEra!: the Japanese era, not null
yearOfEra Int: the Japanese year-of-era
month Int: the Japanese month-of-year, from 1 to 12
dayOfMonth Int: the Japanese day-of-month, from 1 to 31
Return
JapaneseDate! the date in Japanese calendar system, not null
Exceptions
java.time.DateTimeException if the value of any field is out of range, or if the day-of-month is invalid for the month-year, or if the date is not a Japanese era

plus

Added in API level 26
fun plus(amount: TemporalAmount!): JapaneseDate!

Returns an object of the same type as this object with an amount added.

This adjusts this temporal, adding according to the rules of the specified amount. The amount is typically a java.time.Period but may be any other type implementing the TemporalAmount interface, such as java.time.Duration.

Some example code indicating how and why this method is used:

date = date.plus(period);                // add a Period instance
   date = date.plus(duration);              // add a Duration instance
   date = date.plus(workingDays(6));        // example user-written workingDays method
  

Note that calling plus followed by minus is not guaranteed to return the same date-time.

Parameters
amount TemporalAmount!: the amount to add, not null
Return
JapaneseDate! an object of the same type with the specified adjustment made, not null
Exceptions
java.time.DateTimeException if the addition cannot be made
java.lang.ArithmeticException if numeric overflow occurs

plus

Added in API level 26
fun plus(
    amountToAdd: Long,
    unit: TemporalUnit!
): JapaneseDate!
Parameters
amountToAdd Long: the amount of the specified unit to add, may be negative
unit TemporalUnit!: the unit of the amount to add, not null
Return
JapaneseDate! an object of the same type with the specified period added, not null
Exceptions
java.time.DateTimeException if the unit cannot be added
java.time.temporal.UnsupportedTemporalTypeException if the unit is not supported
java.lang.ArithmeticException if numeric overflow occurs

range

Added in API level 26
fun range(field: TemporalField!): ValueRange!
Parameters
field TemporalField!: the field to query the range for, not null
Return
ValueRange! the range of valid values for the field, not null
Exceptions
java.time.DateTimeException if the range for the field cannot be obtained
java.time.temporal.UnsupportedTemporalTypeException if the field is not supported

toEpochDay

Added in API level 26
fun toEpochDay(): Long
Return
Long the Epoch Day equivalent to this date

toString

Added in API level 26
fun toString(): String
Return
String the formatted date, not null

until

Added in API level 26
fun until(endDate: ChronoLocalDate!): ChronoPeriod!
Parameters
endDateExclusive the end date, exclusive, which may be in any chronology, not null
Return
ChronoPeriod! the period between this date and the end date, not null
Exceptions
java.time.DateTimeException if the period cannot be calculated
java.lang.ArithmeticException if numeric overflow occurs

until

Added in API level 26
fun until(
    endExclusive: Temporal!,
    unit: TemporalUnit!
): Long
Parameters
endExclusive Temporal!: the end temporal, exclusive, converted to be of the same type as this object, not null
unit TemporalUnit!: the unit to measure the amount in, not null
Return
Long the amount of time between this temporal object and the specified one in terms of the unit; positive if the specified object is later than this one, negative if it is earlier than this one
Exceptions
java.time.DateTimeException if the amount cannot be calculated, or the end temporal cannot be converted to the same type as this temporal
java.time.temporal.UnsupportedTemporalTypeException if the unit is not supported
java.lang.ArithmeticException if numeric overflow occurs

with

Added in API level 26
fun with(adjuster: TemporalAdjuster!): JapaneseDate!

Returns an adjusted object of the same type as this object with the adjustment made.

This adjusts this date-time according to the rules of the specified adjuster. A simple adjuster might simply set the one of the fields, such as the year field. A more complex adjuster might set the date to the last day of the month. A selection of common adjustments is provided in TemporalAdjusters. These include finding the "last day of the month" and "next Wednesday". The adjuster is responsible for handling special cases, such as the varying lengths of month and leap years.

Some example code indicating how and why this method is used:

date = date.with(Month.JULY);        // most key classes implement TemporalAdjuster
   date = date.with(lastDayOfMonth());  // static import from Adjusters
   date = date.with(next(WEDNESDAY));   // static import from Adjusters and DayOfWeek
  
Parameters
adjuster TemporalAdjuster!: the adjuster to use, not null
Return
JapaneseDate! an object of the same type with the specified adjustment made, not null
Exceptions
java.time.DateTimeException if unable to make the adjustment
java.lang.ArithmeticException if numeric overflow occurs

with

Added in API level 26
fun with(
    field: TemporalField!,
    newValue: Long
): JapaneseDate!
Parameters
field TemporalField!: the field to set in the result, not null
newValue Long: the new value of the field in the result
Return
JapaneseDate! an object of the same type with the specified field set, not null
Exceptions
java.time.DateTimeException if the field cannot be set
java.time.temporal.UnsupportedTemporalTypeException if the field is not supported
java.lang.ArithmeticException if numeric overflow occurs