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Temporal

Extends:

TemporalAccessor → Temporal

Direct Subclass:

DefaultInterfaceTemporal, Instant, LocalTime, packages/core/src/format/DateTimeParseContext.js~Parsed, Year, YearMonth

Framework-level interface defining read-write access to a temporal object, such as a date, time, offset or some combination of these.

This is the base interface type for date, time and offset objects that are complete enough to be manipulated using plus and minus. It is implemented by those classes that can provide and manipulate information as fields (see TemporalField) or queries (see TemporalQuery). See TemporalAccessor for the read-only version of this interface.

Most date and time information can be represented as a number. These are modeled using TemporalField with the number held using a long to handle large values. Year, month and day-of-month are simple examples of fields, but they also include instant and offsets. See ChronoField for the standard set of fields.

Two pieces of date/time information cannot be represented by numbers, the Chronology and the ZoneId. These can be accessed using the static methods defined on TemporalQueries.

This interface is a framework-level interface that should not be widely used in application code. Instead, applications should create and pass around instances of concrete types, such as LocalDate. There are many reasons for this, part of which is that implementations of this interface may be in calendar systems other than ISO. See ChronoLocalDate for a fuller discussion of the issues.

When to implement

A class should implement this interface if it meets three criteria:

  • it provides access to date/time/offset information, as per TemporalAccessor
  • the set of fields are contiguous from the largest to the smallest
  • the set of fields are complete, such that no other field is needed to define the valid range of values for the fields that are represented

Four examples make this clear:

  • LocalDate implements this interface as it represents a set of fields that are contiguous from days to forever and require no external information to determine the validity of each date. It is therefore able to implement plus/minus correctly.
  • LocalTime implements this interface as it represents a set of fields that are contiguous from nanos to within days and require no external information to determine validity. It is able to implement plus/minus correctly, by wrapping around the day.
  • MonthDay, the combination of month-of-year and day-of-month, does not implement this interface. While the combination is contiguous, from days to months within years, the combination does not have sufficient information to define the valid range of values for day-of-month. As such, it is unable to implement plus/minus correctly.
  • The combination day-of-week and day-of-month ("Friday the 13th") should not implement this interface. It does not represent a contiguous set of fields, as days to weeks overlaps days to months.

Method Summary

Public Methods
public

isSupported(unit: TemporalUnit): boolean

Checks if the specified unit is supported.

public

function overloading for Temporal.plus

public

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

public

minusAmountUnit(amountToSubtract: number, unit: TemporalUnit): Temporal

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

public

function overloading for Temporal.plus

public

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

public

plusAmountUnit(amountToAdd: number, unit: TemporalUnit): Temporal

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

public

until(endTemporal: Temporal, unit: TemporalUnit): number

Calculates the period between this temporal and another temporal in terms of the specified unit.

public

function overloading for Temporal.with

public

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

public

withFieldValue(field: TemporalField, newValue: number): Temporal

Returns an object of the same type as this object with the specified field altered.

Inherited Summary

From class TemporalAccessor
public

get(field: TemporalField): number

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.

Public Methods

public isSupported(unit: TemporalUnit): boolean source

Checks if the specified unit is supported. This checks if the date-time can be queried for the specified unit. If false, then calling the plus and minus methods will throw an exception.

Specification for implementors

Implementations must check and handle all fields defined in ChronoUnit. If the field is supported, then true is returned, otherwise false If the field is not a ChronoUnit, then the result of this method is obtained by invoking TemporalUnit.isSupportedBy(Temporal) passing this as the argument.

Implementations must not alter this object.

Params:

NameTypeAttributeDescription
unit TemporalUnit

the unit to check, null returns false

Return:

boolean

true if this date-time can be queried for the unit, false if not

public minus(p1: TemporalAmount | number, p2: TemporalUnit): Temporal source

function overloading for Temporal.plus

Called with 1 (or less) arguments, p1 is expected to be a TemporalAmount and Temporal.minusAmount is called.

Otherwise Temporal.minusAmountUnit is called.

Params:

NameTypeAttributeDescription
p1 TemporalAmount | number
  • nullable: false
p2 TemporalUnit

Return:

Temporal

public minusAmount(amount: TemporalAmount): Temporal source

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 Period but may be any other type implementing the TemporalAmount interface, such as 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.

Specification for implementors

Implementations must not alter either this object. Instead, an adjusted copy of the original must be returned. This provides equivalent, safe behavior for immutable and mutable implementations.

Params:

NameTypeAttributeDescription
amount TemporalAmount

the amount to subtract, not null

Return:

Temporal

an object of the same type with the specified adjustment made, not null

Throw:

*

DateTimeException - if the subtraction cannot be made

*

ArithmeticException - if numeric overflow occurs

public minusAmountUnit(amountToSubtract: number, unit: TemporalUnit): Temporal source

Returns an object of the same type as this object with the specified period subtracted. This method returns a new object based on this one with the specified period subtracted. For example, on a LocalDate, this could be used to subtract a number of years, months or days. The returned object will have the same observable type as this object.

In some cases, changing a field is not fully defined. For example, if the target object is a date representing the 31st March, then subtracting one month would be unclear. In cases like this, the field is responsible for resolving the result. Typically it will choose the previous valid date, which would be the last valid day of February in this example.

If the implementation represents a date-time that has boundaries, such as LocalTime, then the permitted units must include the boundary unit, but no multiples of the boundary unit. For example, LocalTime must accept DAYS but not WEEKS or MONTHS.

Specification for implementors

Implementations must behave in a manor equivalent to the default method behavior. Implementations must not alter either this object or the specified temporal object. Instead, an adjusted copy of the original must be returned. This provides equivalent, safe behavior for immutable and mutable implementations.

Params:

NameTypeAttributeDescription
amountToSubtract number

the amount of the specified unit to subtract, may be negative

unit TemporalUnit

the unit of the period to subtract, not null

Return:

Temporal

an object of the same type with the specified period subtracted, not null

Throw:

*

DateTimeException - if the unit cannot be subtracted

*

ArithmeticException - if numeric overflow occurs

public plus(p1: TemporalAmount | number, p2: TemporalUnit): Temporal source

function overloading for Temporal.plus

Called with 1 (or less) arguments, p1 is expected to be a TemporalAmount and Temporal.plusAmount is called.

Otherwise Temporal.plusAmountUnit is called.

Params:

NameTypeAttributeDescription
p1 TemporalAmount | number
  • nullable: false
p2 TemporalUnit

Return:

Temporal

public plusAmount(amount: TemporalAmount): Temporal source

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 Period but may be any other type implementing the TemporalAmount interface, such as 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.

Specification for implementors

Implementations must not alter either this object. Instead, an adjusted copy of the original must be returned. This provides equivalent, safe behavior for immutable and mutable implementations.

Params:

NameTypeAttributeDescription
amount TemporalAmount

the amount to add, not null

Return:

Temporal

an object of the same type with the specified adjustment made, not null

Throw:

*

DateTimeException - if the addition cannot be made

*

ArithmeticException - if numeric overflow occurs

public plusAmountUnit(amountToAdd: number, unit: TemporalUnit): Temporal source

Returns an object of the same type as this object with the specified period added. This method returns a new object based on this one with the specified period added. For example, on a LocalDate, this could be used to add a number of years, months or days. The returned object will have the same observable type as this object.

In some cases, changing a field is not fully defined. For example, if the target object is a date representing the 31st January, then adding one month would be unclear. In cases like this, the field is responsible for resolving the result. Typically it will choose the previous valid date, which would be the last valid day of February in this example.

If the implementation represents a date-time that has boundaries, such as LocalTime, then the permitted units must include the boundary unit, but no multiples of the boundary unit. For example, LocalTime must accept DAYS but not WEEKS or MONTHS.

Specification for implementors

Implementations must check and handle all units defined in ChronoUnit. If the unit is supported, then the addition must be performed. If unsupported, then a DateTimeException must be thrown. If the unit is not a ChronoUnit, then the result of this method is obtained by invoking TemporalUnit.addTo(Temporal, long) passing this as the first argument.

Implementations must not alter either this object or the specified temporal object. Instead, an adjusted copy of the original must be returned. This provides equivalent, safe behavior for immutable and mutable implementations.

Params:

NameTypeAttributeDescription
amountToAdd number

the amount of the specified unit to add, may be negative

unit TemporalUnit

the unit of the period to add, not null

Return:

Temporal

an object of the same type with the specified period added, not null

Throw:

*

DateTimeException - if the unit cannot be added

*

ArithmeticException - if numeric overflow occurs

public until(endTemporal: Temporal, unit: TemporalUnit): number source

Calculates the period between this temporal and another temporal in terms of the specified unit. This calculates the period between two temporals in terms of a single unit. The start and end points are this and the specified temporal. The result will be negative if the end is before the start. For example, the period in hours between two temporal objects can be calculated using startTime.until(endTime, HOURS).

The calculation returns a whole number, representing the number of complete units between the two temporals. For example, the period in hours between the times 11:30 and 13:29 will only be one hour as it is one minute short of two hours.

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

   // these two lines are equivalent
   between = thisUnit.between(start, end);
   between = start.until(end, thisUnit);

The choice should be made based on which makes the code more readable. For example, this method allows the number of days between two dates to be calculated:

   long daysBetween = DAYS.between(start, end);
   // or alternatively
   long daysBetween = start.until(end, DAYS);

Specification for implementors

Implementations must begin by checking to ensure that the input temporal object is of the same observable type as the implementation. They must then perform the calculation for all instances of ChronoUnit. A DateTimeException must be thrown for ChronoUnit instances that are unsupported. 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 input temporal as the second argument.

In summary, implementations must behave in a manner equivalent to this code:

  // check input temporal is the same type as this class
  if (unit instanceof ChronoUnit) {
    // if unit is supported, then calculate and return result
    // else throw DateTimeException for unsupported units
  }
  return unit.between(this, endTemporal);

The target object must not be altered by this method.

Params:

NameTypeAttributeDescription
endTemporal Temporal

the end temporal, of the same type as this object, not null

unit TemporalUnit

the unit to measure the period in, not null

Return:

number

the amount of the period between this and the end

Throw:

*

DateTimeException - if the period cannot be calculated

*

ArithmeticException - if numeric overflow occurs

public with(p1: TemporalAdjuster | TemporalField, p2: number): Temporal source

function overloading for Temporal.with

Called with 1 (or less) arguments, p1 is expected to be a TemporalAdjuster and Temporal.withAdjuster is called.

Otherwise Temporal.withFieldValue is called.

Params:

NameTypeAttributeDescription
p1 TemporalAdjuster | TemporalField
  • nullable: false
p2 number

Return:

Temporal

public withAdjuster(adjuster: TemporalAdjuster): Temporal source

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 TemporalAdjusters
  date = date.with(next(WEDNESDAY));   // static import from TemporalAdjusters and DayOfWeek

Specification for implementors

Implementations must not alter either this object. Instead, an adjusted copy of the original must be returned. This provides equivalent, safe behavior for immutable and mutable implementations.

Params:

NameTypeAttributeDescription
adjuster TemporalAdjuster

the adjuster to use, not null

Return:

Temporal

an object of the same type with the specified adjustment made, not null

Throw:

*

DateTimeException - if unable to make the adjustment

*

ArithmeticException - if numeric overflow occurs

public withFieldValue(field: TemporalField, newValue: number): Temporal source

Returns an object of the same type as this object with the specified field altered. This returns a new object based on this one with the value for the specified field changed. For example, on a LocalDate, this could be used to set the year, month or day-of-month. The returned object will have the same observable type as this object.

In some cases, changing a field is not fully defined. For example, if the target object is a date representing the 31st January, then changing the month to February would be unclear. In cases like this, the field is responsible for resolving the result. Typically it will choose the previous valid date, which would be the last valid day of February in this example.

Specification for implementors

Implementations must check and handle all fields defined in ChronoField. If the field is supported, then the adjustment must be performed. If unsupported, then a DateTimeException must be thrown. 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 first argument.

Implementations must not alter either this object or the specified temporal object. Instead, an adjusted copy of the original must be returned. This provides equivalent, safe behavior for immutable and mutable implementations.

Params:

NameTypeAttributeDescription
field TemporalField

the field to set in the result, not null

newValue number

the new value of the field in the result

Return:

Temporal

an object of the same type with the specified field set, not null

Throw:

*

DateTimeException - if the field cannot be set

*

ArithmeticException - if numeric overflow occurs