Added in API level 26

Year

class Year : Temporal, TemporalAdjuster, Comparable<Year!>, Serializable
kotlin.Any
   ↳ java.time.Year

A year in the ISO-8601 calendar system, such as 2007.

Year is an immutable date-time object that represents a year. Any field that can be derived from a year can be obtained.

Note that years in the ISO chronology only align with years in the Gregorian-Julian system for modern years. Parts of Russia did not switch to the modern Gregorian/ISO rules until 1920. As such, historical years must be treated with caution.

This class does not store or represent a month, day, time or time-zone. For example, the value "2007" can be stored in a Year.

Years represented by this class follow the ISO-8601 standard and use the proleptic numbering system. Year 1 is preceded by year 0, then by year -1.

The ISO-8601 calendar system is the modern civil calendar system used today in most of the world. It is equivalent to the proleptic Gregorian calendar system, in which today's rules for leap years are applied for all time. For most applications written today, the ISO-8601 rules are entirely suitable. However, any application that makes use of historical dates, and requires them to be accurate will find the ISO-8601 approach unsuitable.

Summary

Constants
static Int

The maximum supported year, '+999,999,999'.
static Int

The minimum supported year, '-999,999,999'.
Public methods
Temporal!
adjustInto(temporal: Temporal!)

Adjusts the specified temporal object to have this year.
LocalDate!
atDay(dayOfYear: Int)

Combines this year with a day-of-year to create a LocalDate.
YearMonth!
atMonth(month: Month!)

Combines this year with a month to create a YearMonth.
YearMonth!
atMonth(month: Int)

Combines this year with a month to create a YearMonth.
LocalDate!
atMonthDay(monthDay: MonthDay!)

Combines this year with a month-day to create a LocalDate.
Int
compareTo(other: Year!)

Compares this year to another year.
Boolean
equals(other: Any?)

Checks if this year is equal to another year.
String!

Formats this year using the specified formatter.
static Year!
from(temporal: TemporalAccessor!)

Obtains an instance of Year from a temporal object.
Int
get(field: TemporalField!)

Gets the value of the specified field from this year as an int.
Long

Gets the value of the specified field from this year as a long.
Int

Gets the year value.
Int

A hash code for this year.
Boolean
isAfter(other: Year!)

Checks if this year is after the specified year.
Boolean
isBefore(other: Year!)

Checks if this year is before the specified year.
Boolean

Checks if the year is a leap year, according to the ISO proleptic calendar system rules.
static Boolean
isLeap(year: Long)

Checks if the year is a leap year, according to the ISO proleptic calendar system rules.
Boolean

Checks if the specified field is supported.
Boolean

Checks if the specified unit is supported.
Boolean

Checks if the month-day is valid for this year.
Int

Gets the length of this year in days.
Year!
minus(amountToSubtract: TemporalAmount!)

Returns a copy of this year with the specified amount subtracted.
Year!
minus(amountToSubtract: Long, unit: TemporalUnit!)

Returns a copy of this year with the specified amount subtracted.
Year!
minusYears(yearsToSubtract: Long)

Returns a copy of this Year with the specified number of years subtracted.
static Year!
now()

Obtains the current year from the system clock in the default time-zone.
static Year!
now(zone: ZoneId!)

Obtains the current year from the system clock in the specified time-zone.
static Year!
now(clock: Clock!)

Obtains the current year from the specified clock.
static Year!
of(isoYear: Int)

Obtains an instance of Year.
static Year!

Obtains an instance of Year from a text string such as 2007.
static Year!
parse(text: CharSequence!, formatter: DateTimeFormatter!)

Obtains an instance of Year from a text string using a specific formatter.
Year!
plus(amountToAdd: TemporalAmount!)

Returns a copy of this year with the specified amount added.
Year!
plus(amountToAdd: Long, unit: TemporalUnit!)

Returns a copy of this year with the specified amount added.
Year!
plusYears(yearsToAdd: Long)

Returns a copy of this Year with the specified number of years added.
R
query(query: TemporalQuery<R>!)

Queries this year using the specified query.
ValueRange!

Gets the range of valid values for the specified field.
String

Outputs this year as a String.
Long
until(endExclusive: Temporal!, unit: TemporalUnit!)

Calculates the amount of time until another year in terms of the specified unit.
Year!
with(adjuster: TemporalAdjuster!)

Returns an adjusted copy of this year.
Year!
with(field: TemporalField!, newValue: Long)

Returns a copy of this year with the specified field set to a new value.

Constants

MAX_VALUE

Added in API level 26
static val MAX_VALUE: Int

The maximum supported year, '+999,999,999'.

Value: 999999999

MIN_VALUE

Added in API level 26
static val MIN_VALUE: Int

The minimum supported year, '-999,999,999'.

Value: -999999999

Public methods

adjustInto

Added in API level 26
fun adjustInto(temporal: Temporal!): Temporal!

Adjusts the specified temporal object to have this year.

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

The adjustment is equivalent to using Temporal#with(TemporalField, long) passing ChronoField#YEAR as the field. If the specified temporal object does not use the ISO calendar system then a DateTimeException is thrown.

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 = thisYear.adjustInto(temporal);
    temporal = temporal.with(thisYear);

This instance is immutable and unaffected by this method call.

Parameters
temporal Temporal!: the target object to be adjusted, not null
Return
Temporal! the adjusted object, not null
Exceptions
java.time.DateTimeException if unable to make the adjustment
java.lang.ArithmeticException if numeric overflow occurs

atDay

Added in API level 26
fun atDay(dayOfYear: Int): LocalDate!

Combines this year with a day-of-year to create a LocalDate.

This returns a LocalDate formed from this year and the specified day-of-year.

The day-of-year value 366 is only valid in a leap year.

Parameters
dayOfYear Int: the day-of-year to use, from 1 to 365-366
Return
LocalDate! the local date formed from this year and the specified date of year, not null
Exceptions
java.time.DateTimeException if the day of year is zero or less, 366 or greater or equal to 366 and this is not a leap year

atMonth

Added in API level 26
fun atMonth(month: Month!): YearMonth!

Combines this year with a month to create a YearMonth.

This returns a YearMonth formed from this year and the specified month. All possible combinations of year and month are valid.

This method can be used as part of a chain to produce a date: 

LocalDate date = year.atMonth(month).atDay(day);
Parameters
month Month!: the month-of-year to use, not null
Return
YearMonth! the year-month formed from this year and the specified month, not null

atMonth

Added in API level 26
fun atMonth(month: Int): YearMonth!

Combines this year with a month to create a YearMonth.

This returns a YearMonth formed from this year and the specified month. All possible combinations of year and month are valid.

This method can be used as part of a chain to produce a date: 

LocalDate date = year.atMonth(month).atDay(day);
Parameters
month Int: the month-of-year to use, from 1 (January) to 12 (December)
Return
YearMonth! the year-month formed from this year and the specified month, not null
Exceptions
java.time.DateTimeException if the month is invalid

atMonthDay

Added in API level 26
fun atMonthDay(monthDay: MonthDay!): LocalDate!

Combines this year with a month-day to create a LocalDate.

This returns a LocalDate formed from this year and the specified month-day.

A month-day of February 29th will be adjusted to February 28th in the resulting date if the year is not a leap year.

Parameters
monthDay MonthDay!: the month-day to use, not null
Return
LocalDate! the local date formed from this year and the specified month-day, not null

compareTo

Added in API level 26
fun compareTo(other: Year!): Int

Compares this year to another year.

The comparison is based on the value of the year. It is "consistent with equals", as defined by Comparable.

Parameters
o the object to be compared.
other Year!: the other year to compare to, not null
Return
Int the comparator value, negative if less, positive if greater
Exceptions
java.lang.NullPointerException if the specified object is null
java.lang.ClassCastException if the specified object's type prevents it from being compared to this object.

equals

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

Checks if this year is equal to another year.

The comparison is based on the time-line position of the years.

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

format

Added in API level 26
fun format(formatter: DateTimeFormatter!): String!

Formats this year using the specified formatter.

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

Parameters
formatter DateTimeFormatter!: the formatter to use, not null
Return
String! the formatted year string, not null
Exceptions
java.time.DateTimeException if an error occurs during printing

from

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

Obtains an instance of Year from a temporal object.

This obtains a year based on the specified temporal. A TemporalAccessor represents an arbitrary set of date and time information, which this factory converts to an instance of Year.

The conversion extracts the year field. The extraction is only permitted if the temporal object has an ISO chronology, or can be converted to a LocalDate.

This method matches the signature of the functional interface TemporalQuery allowing it to be used as a query via method reference, Year::from.

Parameters
temporal TemporalAccessor!: the temporal object to convert, not null
Return
Year! the year, not null
Exceptions
java.time.DateTimeException if unable to convert to a Year

get

Added in API level 26
fun get(field: TemporalField!): Int

Gets the value of the specified field from this year as an int.

This queries this year for the value of the specified field. The returned value will always be within the valid range of values for the field. If it is not possible to return the value, because the field is not supported or for some other reason, an exception is thrown.

If the field is a ChronoField then the query is implemented here. The supported fields will return valid values based on this year. All other ChronoField instances will throw an UnsupportedTemporalTypeException.

If the field is not a ChronoField, then the result of this method is obtained by invoking TemporalField.getFrom(TemporalAccessor) passing this as the argument. Whether the value can be obtained, and what the value represents, is determined by the field.

Parameters
field TemporalField!: the field to get, not null
Return
Int the value for the field
Exceptions
java.time.DateTimeException if a value for the field cannot be obtained or the value is outside the range of valid values for the field
java.time.temporal.UnsupportedTemporalTypeException if the field is not supported or the range of values exceeds an int
java.lang.ArithmeticException if numeric overflow occurs

getLong

Added in API level 26
fun getLong(field: TemporalField!): Long

Gets the value of the specified field from this year as a long.

This queries this year for the value of the specified field. If it is not possible to return the value, because the field is not supported or for some other reason, an exception is thrown.

If the field is a ChronoField then the query is implemented here. The supported fields will return valid values based on this year. All other ChronoField instances will throw an UnsupportedTemporalTypeException.

If the field is not a ChronoField, then the result of this method is obtained by invoking TemporalField.getFrom(TemporalAccessor) passing this as the argument. Whether the value can be obtained, and what the value represents, is determined by the field.

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

getValue

Added in API level 26
fun getValue(): Int

Gets the year value.

The year returned by this method is proleptic as per get(YEAR).

Return
Int the year, MIN_VALUE to MAX_VALUE

hashCode

Added in API level 26
fun hashCode(): Int

A hash code for this year.

Return
Int a suitable hash code

isAfter

Added in API level 26
fun isAfter(other: Year!): Boolean

Checks if this year is after the specified year.

Parameters
other Year!: the other year to compare to, not null
Return
Boolean true if this is after the specified year

isBefore

Added in API level 26
fun isBefore(other: Year!): Boolean

Checks if this year is before the specified year.

Parameters
other Year!: the other year to compare to, not null
Return
Boolean true if this point is before the specified year

isLeap

Added in API level 26
fun isLeap(): Boolean

Checks if the year is a leap year, according to the ISO proleptic calendar system rules.

This method applies the current rules for leap years across the whole time-line. In general, a year is a leap year if it is divisible by four without remainder. However, years divisible by 100, are not leap years, with the exception of years divisible by 400 which are.

For example, 1904 is a leap year it is divisible by 4. 1900 was not a leap year as it is divisible by 100, however 2000 was a leap year as it is divisible by 400.

The calculation is proleptic - applying the same rules into the far future and far past. This is historically inaccurate, but is correct for the ISO-8601 standard.

Return
Boolean true if the year is leap, false otherwise

isLeap

Added in API level 26
static fun isLeap(year: Long): Boolean

Checks if the year is a leap year, according to the ISO proleptic calendar system rules.

This method applies the current rules for leap years across the whole time-line. In general, a year is a leap year if it is divisible by four without remainder. However, years divisible by 100, are not leap years, with the exception of years divisible by 400 which are.

For example, 1904 is a leap year it is divisible by 4. 1900 was not a leap year as it is divisible by 100, however 2000 was a leap year as it is divisible by 400.

The calculation is proleptic - applying the same rules into the far future and far past. This is historically inaccurate, but is correct for the ISO-8601 standard.

Parameters
year Long: the year to check
Return
Boolean true if the year is leap, false otherwise

isSupported

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

Checks if the specified field is supported.

This checks if this year can be queried for the specified field. If false, then calling the range, get and with(java.time.temporal.TemporalField,long) methods will throw an exception.

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

  • 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 year, false if not

isSupported

Added in API level 26
fun isSupported(unit: TemporalUnit!): Boolean

Checks if the specified unit is supported.

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

If the unit is a ChronoUnit then the query is implemented here. The supported units are:

  • YEARS
  • DECADES
  • CENTURIES
  • MILLENNIA
  • ERAS
All other ChronoUnit instances will return false.

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.

Parameters
unit TemporalUnit!: the unit to check, null returns false
Return
Boolean true if the unit can be added/subtracted, false if not

isValidMonthDay

Added in API level 26
fun isValidMonthDay(monthDay: MonthDay!): Boolean

Checks if the month-day is valid for this year.

This method checks whether this year and the input month and day form a valid date.

Parameters
monthDay MonthDay!: the month-day to validate, null returns false
Return
Boolean true if the month and day are valid for this year

length

Added in API level 26
fun length(): Int

Gets the length of this year in days.

Return
Int the length of this year in days, 365 or 366

minus

Added in API level 26
fun minus(amountToSubtract: TemporalAmount!): Year!

Returns a copy of this year with the specified amount subtracted.

This returns a Year, based on this one, with the specified amount subtracted. The amount is typically Period but may be any other type implementing the TemporalAmount interface.

The calculation is delegated to the amount object by calling TemporalAmount#subtractFrom(Temporal). The amount implementation is free to implement the subtraction in any way it wishes, however it typically calls back to minus(long,java.time.temporal.TemporalUnit). Consult the documentation of the amount implementation to determine if it can be successfully subtracted.

This instance is immutable and unaffected by this method call.

Parameters
amount the amount to subtract, not null
amountToSubtract TemporalAmount!: the amount to subtract, not null
Return
Year! a Year based on this year with the subtraction 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(
    amountToSubtract: Long, 
    unit: TemporalUnit!
): Year!

Returns a copy of this year with the specified amount subtracted.

This returns a Year, based on this one, with the amount in terms of the unit subtracted. If it is not possible to subtract the amount, because the unit is not supported or for some other reason, an exception is thrown.

This method is equivalent to plus(long,java.time.temporal.TemporalUnit) with the amount negated. See that method for a full description of how addition, and thus subtraction, works.

This instance is immutable and unaffected by this method call.

Parameters
amountToSubtract Long: the amount of the unit to subtract from the result, may be negative
unit TemporalUnit!: the unit of the amount to subtract, not null
Return
Year! a Year based on this year with the specified amount subtracted, not null
Exceptions
java.time.DateTimeException if the subtraction cannot be made
java.time.temporal.UnsupportedTemporalTypeException if the unit is not supported
java.lang.ArithmeticException if numeric overflow occurs

minusYears

Added in API level 26
fun minusYears(yearsToSubtract: Long): Year!

Returns a copy of this Year with the specified number of years subtracted.

This instance is immutable and unaffected by this method call.

Parameters
yearsToSubtract Long: the years to subtract, may be negative
Return
Year! a Year based on this year with the year subtracted, not null
Exceptions
java.time.DateTimeException if the result exceeds the supported range

now

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

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

This will query the system clock in the default time-zone to obtain the current year.

Using this method will prevent the ability to use an alternate clock for testing because the clock is hard-coded.

Return
Year! the current year using the system clock and default time-zone, not null

now

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

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

This will query the system clock to obtain the current year. 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
Year! the current year using the system clock, not null

now

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

Obtains the current year from the specified clock.

This will query the specified clock to obtain the current year. 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
Year! the current year, not null

of

Added in API level 26
static fun of(isoYear: Int): Year!

Obtains an instance of Year.

This method accepts a year value from the proleptic ISO calendar system.

The year 2AD/CE is represented by 2.
The year 1AD/CE is represented by 1.
The year 1BC/BCE is represented by 0.
The year 2BC/BCE is represented by -1.

Parameters
isoYear Int: the ISO proleptic year to represent, from MIN_VALUE to MAX_VALUE
Return
Year! the year, not null
Exceptions
java.time.DateTimeException if the field is invalid

parse

Added in API level 26
static fun parse(text: CharSequence!): Year!

Obtains an instance of Year from a text string such as 2007.

The string must represent a valid year.

Parameters
text CharSequence!: the text to parse such as "2007", not null
Return
Year! the parsed year, not null
Exceptions
java.time.format.DateTimeParseException if the text cannot be parsed

parse

Added in API level 26
static fun parse(
    text: CharSequence!, 
    formatter: DateTimeFormatter!
): Year!

Obtains an instance of Year from a text string using a specific formatter.

The text is parsed using the formatter, returning a year.

Parameters
text CharSequence!: the text to parse, not null
formatter DateTimeFormatter!: the formatter to use, not null
Return
Year! the parsed year, not null
Exceptions
java.time.format.DateTimeParseException if the text cannot be parsed

plus

Added in API level 26
fun plus(amountToAdd: TemporalAmount!): Year!

Returns a copy of this year with the specified amount added.

This returns a Year, based on this one, with the specified amount added. The amount is typically Period but may be any other type implementing the TemporalAmount interface.

The calculation is delegated to the amount object by calling TemporalAmount#addTo(Temporal). The amount implementation is free to implement the addition in any way it wishes, however it typically calls back to plus(long,java.time.temporal.TemporalUnit). Consult the documentation of the amount implementation to determine if it can be successfully added.

This instance is immutable and unaffected by this method call.

Parameters
amount the amount to add, not null
amountToAdd TemporalAmount!: the amount to add, not null
Return
Year! a Year based on this year with the addition 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!
): Year!

Returns a copy of this year with the specified amount added.

This returns a Year, based on this one, with the amount in terms of the unit added. If it is not possible to add the amount, because the unit is not supported or for some other reason, an exception is thrown.

If the field is a ChronoUnit then the addition is implemented here. The supported fields behave as follows:

  • YEARS - Returns a Year with the specified number of years added. This is equivalent to plusYears(long).
  • DECADES - Returns a Year with the specified number of decades added. This is equivalent to calling plusYears(long) with the amount multiplied by 10.
  • CENTURIES - Returns a Year with the specified number of centuries added. This is equivalent to calling plusYears(long) with the amount multiplied by 100.
  • MILLENNIA - Returns a Year with the specified number of millennia added. This is equivalent to calling plusYears(long) with the amount multiplied by 1,000.
  • ERAS - Returns a Year with the specified number of eras added. Only two eras are supported so the amount must be one, zero or minus one. If the amount is non-zero then the year is changed such that the year-of-era is unchanged.

All other ChronoUnit instances will throw an UnsupportedTemporalTypeException.

If the field is not a ChronoUnit, then the result of this method is obtained by invoking TemporalUnit.addTo(Temporal, long) passing this as the argument. In this case, the unit determines whether and how to perform the addition.

This instance is immutable and unaffected by this method call.

Parameters
amountToAdd Long: the amount of the unit to add to the result, may be negative
unit TemporalUnit!: the unit of the amount to add, not null
Return
Year! a Year based on this year with the specified amount added, not null
Exceptions
java.time.DateTimeException if the addition cannot be made
java.time.temporal.UnsupportedTemporalTypeException if the unit is not supported
java.lang.ArithmeticException if numeric overflow occurs

plusYears

Added in API level 26
fun plusYears(yearsToAdd: Long): Year!

Returns a copy of this Year with the specified number of years added.

This instance is immutable and unaffected by this method call.

Parameters
yearsToAdd Long: the years to add, may be negative
Return
Year! a Year based on this year with the years added, not null
Exceptions
java.time.DateTimeException if the result exceeds the supported range

query

Added in API level 26
fun <R : Any!> query(query: TemporalQuery<R>!): R

Queries this year using the specified query.

This queries this year 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.

Parameters
<R> the type of the result
query TemporalQuery<R>!: the query to invoke, not null
Return
R the query result, null may be returned (defined by the query)
Exceptions
java.time.DateTimeException if unable to query (defined by the query)
java.lang.ArithmeticException if numeric overflow occurs (defined by the query)

range

Added in API level 26
fun range(field: TemporalField!): ValueRange!

Gets the range of valid values for the specified field.

The range object expresses the minimum and maximum valid values for a field. This year is used to enhance the accuracy of the returned range. If it is not possible to return the range, because the field is not supported or for some other reason, an exception is thrown.

If the field is a ChronoField then the query is implemented here. The supported fields will return appropriate range instances. All other ChronoField instances will throw an UnsupportedTemporalTypeException.

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

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

toString

Added in API level 26
fun toString(): String

Outputs this year as a String.

Return
String a string representation of this year, not null

until

Added in API level 26
fun until(
    endExclusive: Temporal!, 
    unit: TemporalUnit!
): Long

Calculates the amount of time until another year in terms of the specified unit.

This calculates the amount of time between two Year objects in terms of a single TemporalUnit. The start and end points are this and the specified year. The result will be negative if the end is before the start. The Temporal passed to this method is converted to a Year using from(java.time.temporal.TemporalAccessor). For example, the amount in decades between two year can be calculated using startYear.until(endYear, DECADES).

The calculation returns a whole number, representing the number of complete units between the two years. For example, the amount in decades between 2012 and 2031 will only be one decade as it is one year short of two decades.

There are two equivalent ways of using this method. The first is to invoke this method. The second is to use TemporalUnit#between(Temporal, Temporal): 

// these two lines are equivalent
    amount = start.until(end, YEARS);
    amount = YEARS.between(start, end);
The choice should be made based on which makes the code more readable.

The calculation is implemented in this method for ChronoUnit. The units YEARS, DECADES, CENTURIES, MILLENNIA and ERAS are supported. Other ChronoUnit values will throw an exception.

If the unit is not a ChronoUnit, then the result of this method is obtained by invoking TemporalUnit.between(Temporal, Temporal) passing this as the first argument and the converted input temporal as the second argument.

This instance is immutable and unaffected by this method call.

Parameters
endExclusive Temporal!: the end date, exclusive, which is converted to a Year, not null
unit TemporalUnit!: the unit to measure the amount in, not null
Return
Long the amount of time between this year and the end year
Exceptions
java.time.DateTimeException if the amount cannot be calculated, or the end temporal cannot be converted to a Year
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!): Year!

Returns an adjusted copy of this year.

This returns a Year, based on this one, with the year adjusted. The adjustment takes place using the specified adjuster strategy object. Read the documentation of the adjuster to understand what adjustment will be made.

The result of this method is obtained by invoking the TemporalAdjuster#adjustInto(Temporal) method on the specified adjuster passing this as the argument.

This instance is immutable and unaffected by this method call.

Parameters
adjuster TemporalAdjuster!: the adjuster to use, not null
Return
Year! a Year based on this with the adjustment made, not null
Exceptions
java.time.DateTimeException if the adjustment cannot be made
java.lang.ArithmeticException if numeric overflow occurs

with

Added in API level 26
fun with(
    field: TemporalField!, 
    newValue: Long
): Year!

Returns a copy of this year with the specified field set to a new value.

This returns a Year, based on this one, with the value for the specified field changed. If it is not possible to set the value, because the field is not supported or for some other reason, an exception is thrown.

If the field is a ChronoField then the adjustment is implemented here. The supported fields behave as follows:

  • YEAR_OF_ERA - Returns a Year with the specified year-of-era The era will be unchanged.
  • YEAR - Returns a Year with the specified year. This completely replaces the date and is equivalent to of(int).
  • ERA - Returns a Year with the specified era. The year-of-era will be unchanged.

In all cases, if the new value is outside the valid range of values for the field then a DateTimeException will be thrown.

All other ChronoField instances will throw an UnsupportedTemporalTypeException.

If the field is not a ChronoField, then the result of this method is obtained by invoking TemporalField.adjustInto(Temporal, long) passing this as the argument. In this case, the field determines whether and how to adjust the instant.

This instance is immutable and unaffected by this method call.

Parameters
field TemporalField!: the field to set in the result, not null
newValue Long: the new value of the field in the result
Return
Year! a Year based on this 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