Temporal
interface Temporal : TemporalAccessor
java.time.temporal.Temporal |
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 or queries. 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 time-zone. These can be accessed via queries
using the static methods defined on TemporalQuery
.
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 java.time.chrono.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.
Summary
Public methods | |
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abstract Boolean |
isSupported(unit: TemporalUnit!) Checks if the specified unit is supported. |
open Temporal! |
minus(amount: TemporalAmount!) Returns an object of the same type as this object with an amount subtracted. |
open Temporal! |
minus(amountToSubtract: Long, unit: TemporalUnit!) Returns an object of the same type as this object with the specified period subtracted. |
open Temporal! |
plus(amount: TemporalAmount!) Returns an object of the same type as this object with an amount added. |
abstract Temporal! |
plus(amountToAdd: Long, unit: TemporalUnit!) Returns an object of the same type as this object with the specified period added. |
abstract Long |
until(endExclusive: Temporal!, unit: TemporalUnit!) Calculates the amount of time until another temporal in terms of the specified unit. |
open Temporal! |
with(adjuster: TemporalAdjuster!) Returns an adjusted object of the same type as this object with the adjustment made. |
abstract Temporal! |
with(field: TemporalField!, newValue: Long) Returns an object of the same type as this object with the specified field altered. |
Inherited functions | |
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Public methods
isSupported
abstract 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 date-time. If false, then calling the plus(long,java.time.temporal.TemporalUnit)
and minus
methods will throw an exception.
Parameters | |
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unit |
TemporalUnit!: the unit to check, null returns false |
Return | |
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Boolean |
true if the unit can be added/subtracted, false if not |
minus
open fun minus(amount: TemporalAmount!): Temporal!
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 | |
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amount |
TemporalAmount!: the amount to subtract, not null |
Return | |
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Temporal! |
an object of the same type with the specified adjustment made, not null |
Exceptions | |
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java.time.DateTimeException |
if the subtraction cannot be made |
java.lang.ArithmeticException |
if numeric overflow occurs |
minus
open fun minus(
amountToSubtract: Long,
unit: TemporalUnit!
): Temporal!
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.
Parameters | |
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amountToSubtract |
Long: the amount of the specified unit to subtract, may be negative |
unit |
TemporalUnit!: the unit of the amount to subtract, not null |
Return | |
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Temporal! |
an object of the same type with the specified period subtracted, not null |
Exceptions | |
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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 |
plus
open fun plus(amount: TemporalAmount!): Temporal!
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 | |
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amount |
TemporalAmount!: the amount to add, not null |
Return | |
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Temporal! |
an object of the same type with the specified adjustment made, not null |
Exceptions | |
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java.time.DateTimeException |
if the addition cannot be made |
java.lang.ArithmeticException |
if numeric overflow occurs |
plus
abstract fun plus(
amountToAdd: Long,
unit: TemporalUnit!
): Temporal!
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.
Parameters | |
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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 | |
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Temporal! |
an object of the same type with the specified period added, not null |
Exceptions | |
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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 |
until
abstract fun until(
endExclusive: Temporal!,
unit: TemporalUnit!
): Long
Calculates the amount of time until another temporal in terms of the specified unit.
This calculates the amount of time between two temporal objects in terms of a single TemporalUnit
. The start and end points are this
and the specified temporal. The end point is converted to be of the same type as the start point if different. The result will be negative if the end is before the start. For example, the amount 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 amount 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 temporal = start.until(end, unit); temporal = unit.between(start, end);
For example, this method allows the number of days between two dates to be calculated:
long daysBetween = start.until(end, DAYS); // or alternatively long daysBetween = DAYS.between(start, end);
Parameters | |
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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 | |
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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 | |
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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
open fun with(adjuster: TemporalAdjuster!): Temporal!
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 | |
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adjuster |
TemporalAdjuster!: the adjuster to use, not null |
Return | |
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Temporal! |
an object of the same type with the specified adjustment made, not null |
Exceptions | |
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java.time.DateTimeException |
if unable to make the adjustment |
java.lang.ArithmeticException |
if numeric overflow occurs |
with
abstract fun with(
field: TemporalField!,
newValue: Long
): Temporal!
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.
Parameters | |
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field |
TemporalField!: the field to set in the result, not null |
newValue |
Long: the new value of the field in the result |
Return | |
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Temporal! |
an object of the same type with the specified field set, not null |
Exceptions | |
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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 |