Combines this time with a time-zone to create a ChronoZonedDateTime
.
Combines this time with a time-zone to create a ChronoZonedDateTime
.
This returns a ChronoZonedDateTime
formed from this date-time at the specified
time-zone. The result will match this date-time as closely as possible. Time-zone rules, such
as daylight savings, mean that not every local date-time is valid for the specified zone, thus
the local date-time may be adjusted.
The local date-time is resolved to a single instant on the time-line. This is achieved by
finding a valid offset from UTC/Greenwich for the local date-time as defined by the ZoneRules rules
of the zone ID.
In most cases, there is only one valid offset for a local date-time. In the case of an overlap, where clocks are set back, there are two valid offsets. This method uses the earlier offset typically corresponding to "summer".
In the case of a gap, where clocks jump forward, there is no valid offset. Instead, the local date-time is adjusted to be later by the length of the gap. For a typical one hour daylight savings change, the local date-time will be moved one hour later into the offset typically corresponding to "summer".
To obtain the later offset during an overlap, call ChronoZonedDateTime#withLaterOffsetAtOverlap()
on the result of this method.
the time-zone to use, not null
the zoned date-time formed from this date-time, not null
Gets the value of the specified field as a long
.
Gets the value of the specified field as a long
.
This queries the date-time for the value for the specified field. The returned value may be outside the valid range of values for the field. If the date-time cannot return the value, because the field is unsupported or for some other reason, an exception will be thrown.
Implementations must check and handle all fields
defined in ChronoField
. If the field is supported, then the value of the field must be
returned. 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.getFrom(TemporalAccessor)
passing this
as the argument.
Implementations must not alter either this object.
the field to get, not null
the value for the field
ArithmeticException
if numeric overflow occurs
DateTimeException
if a value for the field cannot be obtained
Checks if the specified unit is supported.
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.
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.
the unit to check, null returns false
true if this date-time can be queried for the unit, false if not
Checks if the specified field is supported.
Checks if the specified field is supported.
This checks if the date-time can be queried for the specified field. If false, then calling the
range
and get
methods will throw an
exception.
Implementations must check and handle all fields
defined in ChronoField
. If the field is supported, then true is returned, otherwise
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.
Implementations must not alter this object.
the field to check, null returns false
true if this date-time can be queried for the field, false if not
Returns an object of the same type as this object with the specified period added.
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
.
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.
the amount of the specified unit to add, may be negative
the unit of the period to add, not null
an object of the same type with the specified period added, not null
ArithmeticException
if numeric overflow occurs
DateTimeException
if the unit cannot be added
Gets the local date part of this date-time.
Gets the local date part of this date-time.
This returns a local date with the same year, month and day as this date-time.
the date part of this date-time, not null
Gets the local time part of this date-time.
Gets the local time part of this date-time.
This returns a local time with the same hour, minute, second and nanosecond as this date-time.
the time part of this date-time, not null
Calculates the period between this temporal and another temporal in terms of the specified unit.
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 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:
val daysBetween: Long = DAYS.between(start, end); // or alternatively val daysBetween: Long = start.until(end, DAYS);
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.
thisUnit); For example, this method allows the number of days between two dates to be calculated:
val daysBetween: Long = DAYS.between(start, end); // or alternatively val daysBetween: Long = 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.
the end temporal, of the same type as this object, not null
the unit to measure the period in, not null
the amount of the period between this and the end
ArithmeticException
if numeric overflow occurs
DateTimeException
if the period cannot be calculated
Returns an object of the same type as this object with the specified field altered.
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.
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.
the field to set in the result, not null
the new value of the field in the result
an object of the same type with the specified field set, not null
ArithmeticException
if numeric overflow occurs
DateTimeException
if the field cannot be set
Adjusts the specified temporal object.
Adjusts the specified temporal object.
This adjusts the specified temporal object using the logic encapsulated in the implementing class. Examples might be an adjuster that sets the date avoiding weekends, or one that sets the date to the last day of the month.
There are two equivalent ways of using this method. The first is to invoke this method
directly. The second is to use Temporal#with(TemporalAdjuster)
:
// these two lines are equivalent, but the second approach is recommended temporal = thisAdjuster.adjustInto(temporal); temporal = temporal.with(thisAdjuster);It is recommended to use the second approach,
with(TemporalAdjuster)
, as it is a lot clearer
to read in code. The implementation must take the input object and
adjust it. The implementation defines the logic of the adjustment and is responsible for
documenting that logic. It may use any method on Temporal
to query the temporal object
and perform the adjustment. The returned object must have the same observable type as the input
object
The input object must not be altered. Instead, an adjusted copy of the original must be returned. This provides equivalent, safe behavior for immutable and mutable temporal objects.
The input temporal object may be in a calendar system other than ISO. Implementations may
choose to document compatibility with other calendar systems, or reject non-ISO temporal
objects by querying the chronology
.
This method may be called from multiple threads in parallel. It must be thread-safe when invoked.
thisAdjuster.adjustInto(temporal); temporal = temporal.with(thisAdjuster);
recommended to use the second approach, with(TemporalAdjuster)
, as it is a lot clearer
to read in code.
=== Specification for implementors ===
The implementation must take the input object and
adjust it. The implementation defines the logic of the adjustment and is responsible for
documenting that logic. It may use any method on Temporal
to query the temporal object
and perform the adjustment. The returned object must have the same observable type as the input
object
The input object must not be altered. Instead, an adjusted copy of the original must be
returned. This provides equivalent, safe behavior for immutable and mutable temporal objects.
The input temporal object may be in a calendar system other than ISO. Implementations may
choose to document compatibility with other calendar systems, or reject non-ISO temporal
objects by `[[TemporalQueries#chronology() querying the chronology]]`.
This method may be called from multiple threads in parallel. It must be thread-safe when
invoked.
the temporal object to adjust, not null
an object of the same observable type with the adjustment made, not null
ArithmeticException
if numeric overflow occurs
DateTimeException
if unable to make the adjustment
Compares this date-time to another date-time, including the chronology.
Compares this date-time to another date-time, including the chronology.
The comparison is based first on the underlying time-line date-time, then on the chronology. It
is "consistent with equals", as defined by Comparable
.
For example, the following is the comparator order:
2012-12-03T12:00
(ISO)
2012-12-04T12:00 (ISO)
2555-12-04T12:00
(ThaiBuddhist)
2012-12-05T12:00 (ISO)
Values #2 and #3 represent
the same date-time on the time-line. When two values represent the same date-time, the
chronology ID is compared to distinguish them. This step is needed to make the ordering
"consistent with equals".If all the date-time objects being compared are in the same chronology, then the additional chronology stage is not required and only the local date-time is used.
the other date-time to compare to, not null
the comparator value, negative if less, positive if greater
Checks if this date-time is equal to another date-time, including the chronology.
Checks if this date-time is equal to another date-time, including the chronology.
Compares this date-time with another ensuring that the date-time and chronology are the same.
the object to check, null returns false
true if this is equal to the other date
Formats this date-time using the specified formatter.
Formats this date-time using the specified formatter.
This date-time will be passed to the formatter to produce a string.
The default implementation must behave as follows:
return formatter.format(this);
the formatter to use, not null
the formatted date-time string, not null
DateTimeException
if an error occurs during printing
Gets the value of the specified field as an int
.
Gets the value of the specified field as an int
.
This queries the date-time for the value for the specified field. The returned value will always be within the valid range of values for the field. If the date-time cannot return the value, because the field is unsupported or for some other reason, an exception will be thrown.
Implementations must check and handle all fields
defined in ChronoField
. If the field is supported and has an int
range, then
the value of the field must be returned. 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.getFrom(TemporalAccessor)
passing this
as the argument.
Implementations must not alter either this object.
the field to get, not null
the value for the field, within the valid range of values
ArithmeticException
if numeric overflow occurs
DateTimeException
if the value is outside the range of valid values for the field
Gets the chronology of this date-time.
Gets the chronology of this date-time.
The Chronology
represents the calendar system in use. The era and other fields in
ChronoField
are defined by the chronology.
the chronology, not null
A hash code for this date-time.
A hash code for this date-time.
a suitable hash code
Checks if this date-time is after the specified date-time ignoring the chronology.
Checks if this date-time is after the specified date-time ignoring the chronology.
This method differs from the comparison in #compareTo
in that it only compares the
underlying date-time and not the chronology. This allows dates in different calendar systems to
be compared based on the time-line position.
the other date-time to compare to, not null
true if this is after the specified date-time
Checks if this date-time is before the specified date-time ignoring the chronology.
Checks if this date-time is before the specified date-time ignoring the chronology.
This method differs from the comparison in #compareTo
in that it only compares the
underlying date-time and not the chronology. This allows dates in different calendar systems to
be compared based on the time-line position.
the other date-time to compare to, not null
true if this is before the specified date-time
Checks if this date-time is equal to the specified date-time ignoring the chronology.
Checks if this date-time is equal to the specified date-time ignoring the chronology.
This method differs from the comparison in #compareTo
in that it only compares the
underlying date and time and not the chronology. This allows date-times in different calendar
systems to be compared based on the time-line position.
the other date-time to compare to, not null
true if the underlying date-time is equal to the specified date-time on the timeline
Returns an object of the same type as this object with the specified period subtracted.
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
.
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.
the amount of the specified unit to subtract, may be negative
the unit of the period to subtract, not null
an object of the same type with the specified period subtracted, not null
ArithmeticException
if numeric overflow occurs
DateTimeException
if the unit cannot be subtracted
Returns an object of the same type as this object with an amount subtracted.
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.
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.
the amount to subtract, not null
an object of the same type with the specified adjustment made, not null
ArithmeticException
if numeric overflow occurs
DateTimeException
if the subtraction cannot be made
Returns an object of the same type as this object with an amount added.
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.
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.
the amount to add, not null
an object of the same type with the specified adjustment made, not null
ArithmeticException
if numeric overflow occurs
DateTimeException
if the addition cannot be made
Queries this date-time.
Queries this date-time.
This queries this date-time using the specified query strategy object.
Queries are a key tool for extracting information from date-times. They exists to externalize the process of querying, permitting different approaches, as per the strategy design pattern. Examples might be a query that checks if the date is the day before February 29th in a leap year, or calculates the number of days to your next birthday.
The most common query implementations are method references, such as LocalDate::from
and ZoneId::from
. Further implementations are on TemporalQueries
. Queries may
also be defined by applications.
Implementations of this method must behave as follows:
public <R> R query(TemporalQuery<R> type) { // only include an if statement if the implementation can return it if (query == TemporalQueries.zoneId()) return // the ZoneId if (query == TemporalQueries.chronology()) return // the Chrono if (query == TemporalQueries.precision()) return // the precision // call default method return super.query(query); }
the type of the result
the query to invoke, not null
the query result, null may be returned (defined by the query)
ArithmeticException
if numeric overflow occurs
DateTimeException
if unable to query
Gets the range of valid values for the specified field.
Gets the range of valid values for the specified field.
All fields can be expressed as a long
integer. This method returns an object that
describes the valid range for that value. The value of this temporal object is used to enhance
the accuracy of the returned range. If the date-time cannot return the range, because the field
is unsupported or for some other reason, an exception will be thrown.
Note that the result only describes the minimum and maximum valid values and it is important not to read too much into them. For example, there could be values within the range that are invalid for the field.
Implementations must check and handle all fields
defined in ChronoField
. If the field is supported, then the range of the field must be
returned. 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.rangeRefinedBy(TemporalAccessorl)
passing this
as the
argument.
Implementations must not alter either this object.
the field to query the range for, not null
the range of valid values for the field, not null
DateTimeException
if the range for the field cannot be obtained
Converts this date-time to the number of seconds from the epoch of 1970-01-01T00:00:00Z.
Converts this date-time to the number of seconds from the epoch of 1970-01-01T00:00:00Z.
This combines this local date-time and the specified offset to calculate the epoch-second value, which is the number of elapsed seconds from 1970-01-01T00:00:00Z. Instants on the time-line after the epoch are positive, earlier are negative.
the offset to use for the conversion, not null
the number of seconds from the epoch of 1970-01-01T00:00:00Z
Converts this date-time to an Instant
.
Converts this date-time to an Instant
.
This combines this local date-time and the specified offset to form an Instant
.
the offset to use for the conversion, not null
an Instant
representing the same instant, not null
Outputs this date-time as a String
.
Outputs this date-time as a String
.
The output will include the full local date-time and the chronology ID.
a string representation of this date-time, not null
Returns an adjusted object of the same type as this object with the adjustment made.
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
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.
the adjuster to use, not null
an object of the same type with the specified adjustment made, not null
ArithmeticException
if numeric overflow occurs
DateTimeException
if unable to make the adjustment