Home Reference Source
import {MonthDay} from 'js-joda/src/MonthDay.js'
public class | source

MonthDay

Extends:

TemporalAccessorTemporal → MonthDay

A month-day in the ISO-8601 calendar system, such as --12-03.

MonthDay is an immutable date-time object that represents the combination of a year and month. Any field that can be derived from a month and day, such as quarter-of-year, can be obtained.

This class does not store or represent a year, time or time-zone. For example, the value "December 3rd" can be stored in a MonthDay.

Since a MonthDay does not possess a year, the leap day of February 29th is considered valid.

This class implements TemporalAccessor rather than Temporal. This is because it is not possible to define whether February 29th is valid or not without external information, preventing the implementation of plus/minus. Related to this, MonthDay only provides access to query and set the fields MONTH_OF_YEAR and DAY_OF_MONTH.

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.

Specification for implementors

This class is immutable and thread-safe.

Static Method Summary

Static Public Methods
public static

Obtains an instance of MonthDay from a temporal object.

public static

now(zoneIdOrClock: ZoneId | Clock): MonthDay

function overloading for MonthDay.now

public static

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

public static

Obtains the current month-day from the specified clock.

public static

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

public static

of(monthOrNumber: Month | number, number: number): MonthDay

function overloading for MonthDay.of

public static

ofMonthNumber(month: Month, dayOfMonth: number): MonthDay

Obtains an instance of MonthDay.

public static

ofNumberNumber(month: number, dayOfMonth: number): MonthDay

Obtains an instance of MonthDay.

public static

parse(text: String, formatter: DateTimeFormatter): MonthDay

function overloading for MonthDay.parse

public static

Obtains an instance of MonthDay from a text string such as --12-03.

public static

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

Method Summary

Public Methods
public

Adjusts the specified temporal object to have this month-day.

public

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

public

Compares this month-day to another month-day.

public

Gets the day-of-month field.

public

equals(obj: *): boolean

Checks if this month-day is equal to another month-day.

public

Outputs this month-day as a string using the formatter.

public

Gets the value of the specified field from this month-day as an int.

public

Gets the value of the specified field from this month-day as a long.

public

Is this month-day after the specified month-day.

public

Is this month-day before the specified month-day.

public

Checks if the specified field is supported.

public

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

public

Gets the month-of-year field using the Month enum.

public

Gets the month-of-year field from 1 to 12.

public

query(query: TemporalQuery): *

Queries this month-day using the specified query.

public

Gets the range of valid values for the specified field.

public

toJSON() use by JSON.stringify delegates to toString()

public

Outputs this month-day as a string, such as --12-03.

public

with(month: Month): MonthDay

Returns a copy of this MonthDay with the month-of-year altered.

public

Returns a copy of this MonthDay with the day-of-month altered.

public

Returns a copy of this MonthDay with the month-of-year altered.

Inherited Summary

From class TemporalAccessor
public

Gets the value of the specified field as an int.

public

query(query: TemporalQuery): *

Queries this date-time.

public

Gets the range of valid values for the specified field.

Static Public Methods

public static from(temporal: TemporalAccessor): MonthDay source

Obtains an instance of MonthDay from a temporal object.

A TemporalAccessor represents some form of date and time information. This factory converts the arbitrary temporal object to an instance of MonthDay.

The conversion extracts the MONTH_OF_YEAR (see ChronoField#MONTH_OF_YEAR) and DAY_OF_MONTH (see ChronoField#DAY_OF_MONTH) fields. The extraction is only permitted if the date-time has an ISO chronology.

This method matches the signature of the functional interface TemporalQuery allowing it to be used in queries via method reference, MonthDay::from.

Params:

NameTypeAttributeDescription
temporal TemporalAccessor

the temporal object to convert, not null

Return:

MonthDay

the month-day, not null

Throw:

*

DateTimeException if unable to convert to a MonthDay

public static now(zoneIdOrClock: ZoneId | Clock): MonthDay source

function overloading for MonthDay.now

if called with 0 argument MonthDay.now0 is executed,

if called with 1 argument and first argument is an instance of ZoneId, then MonthDay.nowZoneId is executed,

otherwise MonthDay.nowClock is executed

Params:

NameTypeAttributeDescription
zoneIdOrClock ZoneId | Clock
  • nullable: true

Return:

MonthDay

public static now0(): MonthDay source

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

This will query the system clock (see Clock#systemDefaultZone) in the default time-zone to obtain the current month-day.

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

Return:

MonthDay

the current month-day using the system clock and default time-zone, not null

public static nowClock(clock: Clock): MonthDay source

Obtains the current month-day from the specified clock.

This will query the specified clock to obtain the current month-day. Using this method allows the use of an alternate clock for testing. The alternate clock may be introduced using dependency injection (see Clock).

Params:

NameTypeAttributeDescription
clock Clock

the clock to use, not null

Return:

MonthDay

the current month-day, not null

public static nowZoneId(zone: ZoneId): MonthDay source

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

This will query the system clock (see Clock#system) to obtain the current month-day. 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.

Params:

NameTypeAttributeDescription
zone ZoneId

the zone ID to use, not null

Return:

MonthDay

the current month-day using the system clock, not null

public static of(monthOrNumber: Month | number, number: number): MonthDay source

function overloading for MonthDay.of

if called with 2 argument and first argument is an instance of Month, then MonthDay.ofMonthNumber is executed,

otherwise MonthDay.ofNumberNumber is executed

Params:

NameTypeAttributeDescription
monthOrNumber Month | number
  • nullable: false
number number
  • nullable: true

Return:

MonthDay

public static ofMonthNumber(month: Month, dayOfMonth: number): MonthDay source

Obtains an instance of MonthDay.

The day-of-month must be valid for the month within a leap year. Hence, for February, day 29 is valid.

For example, passing in April and day 31 will throw an exception, as there can never be April 31st in any year. By contrast, passing in February 29th is permitted, as that month-day can sometimes be valid.

Params:

NameTypeAttributeDescription
month Month

the month-of-year to represent, not null

dayOfMonth number

the day-of-month to represent, from 1 to 31

Return:

MonthDay

the month-day, not null

Throw:

*

DateTimeException if the value of any field is out of range

*

DateTimeException if the day-of-month is invalid for the month

public static ofNumberNumber(month: number, dayOfMonth: number): MonthDay source

Obtains an instance of MonthDay.

The day-of-month must be valid for the month within a leap year. Hence, for month 2 (February), day 29 is valid.

For example, passing in month 4 (April) and day 31 will throw an exception, as there can never be April 31st in any year. By contrast, passing in February 29th is permitted, as that month-day can sometimes be valid.

Params:

NameTypeAttributeDescription
month number

the month-of-year to represent, from 1 (January) to 12 (December)

dayOfMonth number

the day-of-month to represent, from 1 to 31

Return:

MonthDay

the month-day, not null

Throw:

*

DateTimeException if the value of any field is out of range

*

DateTimeException if the day-of-month is invalid for the month

public static parse(text: String, formatter: DateTimeFormatter): MonthDay source

function overloading for MonthDay.parse

if called with 1 argument, then MonthDay.parseString is executed,

otherwise MonthDay.parseStringFormatter is executed

Params:

NameTypeAttributeDescription
text String
  • nullable: false
formatter DateTimeFormatter
  • nullable: true

Return:

MonthDay

public static parseString(text: String): MonthDay source

Obtains an instance of MonthDay from a text string such as --12-03.

The string must represent a valid month-day. The format is --MM-dd.

Params:

NameTypeAttributeDescription
text String

the text to parse such as "--12-03", not null

Return:

MonthDay

the parsed month-day, not null

Throw:

*

DateTimeParseException if the text cannot be parsed

public static parseStringFormatter(text: String, formatter: DateTimeFormatter): MonthDay source

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

The text is parsed using the formatter, returning a month-day.

Params:

NameTypeAttributeDescription
text String

the text to parse, not null

formatter DateTimeFormatter

the formatter to use, not null

Return:

MonthDay

the parsed month-day, not null

Throw:

*

DateTimeParseException if the text cannot be parsed

Public Methods

public adjustInto(temporal: Temporal): Temporal source

Adjusts the specified temporal object to have this month-day.

This returns a temporal object of the same observable type as the input with the month and day-of-month changed to be the same as this.

The adjustment is equivalent to using Temporal#with twice, passing ChronoField#MONTH_OF_YEAR and ChronoField#DAY_OF_MONTH as the fields. 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:

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

This instance is immutable and unaffected by this method call.

Params:

NameTypeAttributeDescription
temporal Temporal

the target object to be adjusted, not null

Return:

Temporal

the adjusted object, not null

Throw:

*

DateTimeException if unable to make the adjustment

*

ArithmeticException if numeric overflow occurs

public atYear(year: number): LocalDate source

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

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

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

This instance is immutable and unaffected by this method call.

Params:

NameTypeAttributeDescription
year number

the year to use, from MIN_YEAR to MAX_YEAR

Return:

LocalDate

the local date formed from this month-day and the specified year, not null

Throw:

*

DateTimeException if the year is outside the valid range of years

public compareTo(other: MonthDay): number source

Compares this month-day to another month-day.

The comparison is based first on value of the month, then on the value of the day. It is "consistent with equals", as defined by Comparable.

Params:

NameTypeAttributeDescription
other MonthDay

the other month-day to compare to, not null

Return:

number

the comparator value, negative if less, positive if greater

public dayOfMonth(): number source

Gets the day-of-month field.

This method returns the primitive int value for the day-of-month.

Return:

number

the day-of-month, from 1 to 31

public equals(obj: *): boolean source

Checks if this month-day is equal to another month-day.

The comparison is based on the time-line position of the month-day within a year.

Params:

NameTypeAttributeDescription
obj *

the object to check, null returns false

Return:

boolean

true if this is equal to the other month-day

public format(formatter: DateTimeFormatter): String source

Outputs this month-day as a string using the formatter.

This month-day will be passed to the formatter print method (see DateTimeFormatter#format).

Params:

NameTypeAttributeDescription
formatter DateTimeFormatter

the formatter to use, not null

Return:

String

the formatted month-day string, not null

Throw:

*

DateTimeException if an error occurs during printing

public get(field: TemporalField): number source

Gets the value of the specified field from this month-day as an int.

This queries this month-day for the value for 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 (see isSupported) will return valid values based on this month-day. All other ChronoField instances will throw a DateTimeException.

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

Override:

TemporalAccessor#get

Params:

NameTypeAttributeDescription
field TemporalField

the field to get, not null

Return:

number

the value for the field

Throw:

*

DateTimeException if a value for the field cannot be obtained

*

ArithmeticException if numeric overflow occurs

public getLong(field: TemporalField): number source

Gets the value of the specified field from this month-day as a long.

This queries this month-day for the value for 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 (see isSupported) will return valid values based on this month-day. All other ChronoField instances will throw a DateTimeException.

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

Params:

NameTypeAttributeDescription
field TemporalField

the field to get, not null

Return:

number

the value for the field

Throw:

*

DateTimeException if a value for the field cannot be obtained

*

ArithmeticException if numeric overflow occurs

public isAfter(other: MonthDay): boolean source

Is this month-day after the specified month-day.

Params:

NameTypeAttributeDescription
other MonthDay

the other month-day to compare to, not null

Return:

boolean

true if this is after the specified month-day

public isBefore(other: MonthDay): boolean source

Is this month-day before the specified month-day.

Params:

NameTypeAttributeDescription
other MonthDay

the other month-day to compare to, not null

Return:

boolean

true if this point is before the specified month-day

public isSupported(field: TemporalField): boolean source

Checks if the specified field is supported.

This checks if this month-day can be queried for the specified field. If false, then calling the range (see range) and get (see get) methods will throw an exception.

If the field is a ChronoField then the query is implemented here. The supported fields (see isSupported) will return valid values based on this date-time. The supported fields are:

  • MONTH_OF_YEAR
  • YEAR

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 passing this as the argument. Whether the field is supported is determined by the field.

Params:

NameTypeAttributeDescription
field TemporalField

the field to check, null returns false

Return:

boolean

true if the field is supported on this month-day, false if not

public isValidYear(year: number): boolean source

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

This method checks whether this month and day and the input year form a valid date. This can only return false for February 29th.

Params:

NameTypeAttributeDescription
year number

the year to validate, an out of range value returns false

Return:

boolean

true if the year is valid for this month-day

See:

public month(): Month source

Gets the month-of-year field using the Month enum.

This method returns the enum Month for the month. This avoids confusion as to what int values mean. If you need access to the primitive int value then the enum provides the int value (see Month#getValue).

Return:

Month

the month-of-year, not null

See:

public monthValue(): number source

Gets the month-of-year field from 1 to 12.

This method returns the month as an int from 1 to 12. Application code is frequently clearer if the enum Month is used by calling getMonth.

Return:

number

the month-of-year, from 1 to 12

See:

public query(query: TemporalQuery): * source

Queries this month-day using the specified query.

This queries this month-day 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 method on the specified query passing this as the argument.

Override:

TemporalAccessor#query

Params:

NameTypeAttributeDescription
query TemporalQuery

the query to invoke, not null

Return:

*

the query result, null may be returned (defined by the query)

Throw:

*

DateTimeException if unable to query (defined by the query)

*

ArithmeticException if numeric overflow occurs (defined by the query)

public range(field: TemporalField): ValueRange source

Gets the range of valid values for the specified field.

The range object expresses the minimum and maximum valid values for a field. This month-day 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 (see isSupported) will return appropriate range instances. All other ChronoField instances will throw a DateTimeException.

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

Override:

TemporalAccessor#range

Params:

NameTypeAttributeDescription
field TemporalField

the field to query the range for, not null

Return:

ValueRange

the range of valid values for the field, not null

Throw:

*

DateTimeException if the range for the field cannot be obtained

public toJSON(): string source

toJSON() use by JSON.stringify delegates to toString()

Return:

string

public toString(): String source

Outputs this month-day as a string, such as --12-03.

The output will be in the format --MM-dd:

Return:

String

a string representation of this month-day, not null

public with(month: Month): MonthDay source

Returns a copy of this MonthDay with the month-of-year altered.

This returns a month-day with the specified month. If the day-of-month is invalid for the specified month, the day will be adjusted to the last valid day-of-month.

This instance is immutable and unaffected by this method call.

Params:

NameTypeAttributeDescription
month Month

the month-of-year to set in the returned month-day, not null

Return:

MonthDay

based on this month-day with the requested month, not null

public withDayOfMonth(dayOfMonth: number): MonthDay source

Returns a copy of this MonthDay with the day-of-month altered.

This returns a month-day with the specified day-of-month. If the day-of-month is invalid for the month, an exception is thrown.

This instance is immutable and unaffected by this method call.

Params:

NameTypeAttributeDescription
dayOfMonth number

the day-of-month to set in the return month-day, from 1 to 31

Return:

MonthDay

based on this month-day with the requested day, not null

Throw:

*

DateTimeException if the day-of-month value is invalid

*

DateTimeException if the day-of-month is invalid for the month

public withMonth(month: number): MonthDay source

Returns a copy of this MonthDay with the month-of-year altered.

This returns a month-day with the specified month. If the day-of-month is invalid for the specified month, the day will be adjusted to the last valid day-of-month.

This instance is immutable and unaffected by this method call.

Params:

NameTypeAttributeDescription
month number

the month-of-year to set in the returned month-day, from 1 (January) to 12 (December)

Return:

MonthDay

based on this month-day with the requested month, not null

Throw:

*

DateTimeException if the month-of-year value is invalid