Instant
Related Docs:
object Instant
| package bp
Adjusts the specified temporal object to have this instant.
Adjusts the specified temporal object to have this instant.
This returns a temporal object of the same observable type as the input with the instant changed to be the same as this.
The adjustment is equivalent to using long)
twice, passing ChronoField#INSTANT_SECONDS and
ChronoField#NANO_OF_SECOND as the fields.
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 = thisInstant.adjustInto(temporal); temporal = temporal.with(thisInstant);
This instance is immutable and unaffected by this method call.
the target object to be adjusted, not null
the adjusted object, not null
ArithmeticException if numeric overflow occurs
DateTimeException if unable to make the adjustment
Combines this instant with an offset to create an OffsetDateTime.
Combines this instant with an offset to create an OffsetDateTime.
This returns an OffsetDateTime formed from this instant at the
specified offset from UTC/Greenwich. An exception will be thrown if the
instant is too large to fit into an offset date-time.
This method is equivalent to
ZoneId) OffsetDateTime.ofInstant(this, offset).
the offset to combine with, not null
the offset date-time formed from this instant and the specified offset, not null
DateTimeException if the result exceeds the supported range
Combines this instant with a time-zone to create a ZonedDateTime.
Combines this instant with a time-zone to create a ZonedDateTime.
This returns an ZonedDateTime formed from this instant at the
specified time-zone. An exception will be thrown if the instant is too
large to fit into a zoned date-time.
This method is equivalent to
ZoneId) ZonedDateTime.ofInstant(this, zone).
the zone to combine with, not null
the zoned date-time formed from this instant and the specified zone, not null
DateTimeException if the result exceeds the supported range
Compares this instant to the specified instant.
Compares this instant to the specified instant.
The comparison is based on the time-line position of the instants.
It is "consistent with equals", as defined by Comparable.
the other instant to compare to, not null
the comparator value, negative if less, positive if greater
NullPointerException if otherInstant is null
Checks if this instant is equal to the specified instant.
Checks if this instant is equal to the specified instant.
The comparison is based on the time-line position of the instants.
the other instant, null returns false
true if the other instant is equal to this one
Gets the value of the specified field from this instant as an int.
Gets the value of the specified field from this instant as an int.
This queries this instant 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 will return valid
values based on this date-time, except INSTANT_SECONDS which is too
large to fit in an int and throws a DateTimeException.
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(TemporalAccessor)
passing this as the argument. Whether the value can be obtained,
and what the value represents, is determined by the field.
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
Gets the number of seconds from the Java epoch of 1970-01-01T00:00:00Z.
Gets the number of seconds from the Java epoch of 1970-01-01T00:00:00Z.
The epoch second count is a simple incrementing count of seconds where
second 0 is 1970-01-01T00:00:00Z.
The nanosecond part of the day is returned by getNanosOfSecond.
the seconds from the epoch of 1970-01-01T00:00:00Z
Gets the value of the specified field from this instant as a long.
Gets the value of the specified field from this instant as a long.
This queries this instant 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 will return valid
values based on this date-time.
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(TemporalAccessor)
passing this as the argument. Whether the value can be obtained,
and what the value represents, is determined by the field.
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
Gets the number of nanoseconds, later along the time-line, from the start of the second.
Gets the number of nanoseconds, later along the time-line, from the start of the second.
The nanosecond-of-second value measures the total number of nanoseconds from
the second returned by getEpochSecond.
the nanoseconds within the second, always positive, never exceeds 999,999,999
Returns a hash code for this instant.
Returns a hash code for this instant.
a suitable hash code
Checks if this instant is after the specified instant.
Checks if this instant is after the specified instant.
The comparison is based on the time-line position of the instants.
the other instant to compare to, not null
true if this instant is after the specified instant
NullPointerException if otherInstant is null
Checks if this instant is before the specified instant.
Checks if this instant is before the specified instant.
The comparison is based on the time-line position of the instants.
the other instant to compare to, not null
true if this instant is before the specified instant
NullPointerException if otherInstant is null
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 this instant can be queried for the specified field.
If false, then calling the range and
get methods will throw an exception.
If the field is a ChronoField then the query is implemented here.
The supported fields are:
NANO_OF_SECONDMICRO_OF_SECONDMILLI_OF_SECONDINSTANT_SECONDSAll 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.
the field to check, null returns false
true if the field is supported on this instant, false if not
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 { @inheritDoc}
DateTimeException { @inheritDoc}
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 { @inheritDoc}
DateTimeException { @inheritDoc}
Returns a copy of this instant with the specified duration in milliseconds subtracted.
Returns a copy of this instant with the specified duration in milliseconds subtracted.
This instance is immutable and unaffected by this method call.
the milliseconds to subtract, positive or negative
an { @code Instant} based on this instant with the specified milliseconds subtracted, not null
ArithmeticException if numeric overflow occurs
DateTimeException if the result exceeds the maximum or minimum instant
Returns a copy of this instant with the specified duration in nanoseconds subtracted.
Returns a copy of this instant with the specified duration in nanoseconds subtracted.
This instance is immutable and unaffected by this method call.
the nanoseconds to subtract, positive or negative
an { @code Instant} based on this instant with the specified nanoseconds subtracted, not null
ArithmeticException if numeric overflow occurs
DateTimeException if the result exceeds the maximum or minimum instant
Returns a copy of this instant with the specified duration in seconds subtracted.
Returns a copy of this instant with the specified duration in seconds subtracted.
This instance is immutable and unaffected by this method call.
the seconds to subtract, positive or negative
an { @code Instant} based on this instant with the specified seconds subtracted, not null
ArithmeticException if numeric overflow occurs
DateTimeException if the result exceeds the maximum or minimum instant
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 { @inheritDoc}
DateTimeException { @inheritDoc}
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 { @inheritDoc}
DateTimeException { @inheritDoc}
Returns a copy of this instant with the specified duration in milliseconds added.
Returns a copy of this instant with the specified duration in milliseconds added.
This instance is immutable and unaffected by this method call.
the milliseconds to add, positive or negative
an { @code Instant} based on this instant with the specified milliseconds added, not null
ArithmeticException if numeric overflow occurs
DateTimeException if the result exceeds the maximum or minimum instant
Returns a copy of this instant with the specified duration in nanoseconds added.
Returns a copy of this instant with the specified duration in nanoseconds added.
This instance is immutable and unaffected by this method call.
the nanoseconds to add, positive or negative
an { @code Instant} based on this instant with the specified nanoseconds added, not null
ArithmeticException if numeric overflow occurs
DateTimeException if the result exceeds the maximum or minimum instant
Returns a copy of this instant with the specified duration in seconds added.
Returns a copy of this instant with the specified duration in seconds added.
This instance is immutable and unaffected by this method call.
the seconds to add, positive or negative
an { @code Instant} based on this instant with the specified seconds added, not null
ArithmeticException if numeric overflow occurs
DateTimeException if the result exceeds the maximum or minimum instant
Queries this instant using the specified query.
Queries this instant using the specified query.
This queries this instant 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.
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 (defined by the query)
DateTimeException if unable to query (defined by the query)
Gets the range of valid values for the specified field.
Gets the range of valid values for the specified field.
The range object expresses the minimum and maximum valid values for a field. This instant 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 a DateTimeException.
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.
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 instant to the number of milliseconds from the epoch of 1970-01-01T00:00:00Z.
Converts this instant to the number of milliseconds from the epoch of 1970-01-01T00:00:00Z.
If this instant represents a point on the time-line too far in the future
or past to fit in a long milliseconds, then an exception is thrown.
If this instant has greater than millisecond precision, then the conversion will drop any excess precision information as though the amount in nanoseconds was subject to integer division by one million.
the number of milliseconds since the epoch of 1970-01-01T00:00:00Z
ArithmeticException if numeric overflow occurs
A string representation of this instant using ISO-8601 representation.
A string representation of this instant using ISO-8601 representation.
The format used is the same as DateTimeFormatter#ISO_INSTANT.
an ISO-8601 representation of this instant, not null
Returns a copy of this Instant truncated to the specified unit.
Returns a copy of this Instant truncated to the specified unit.
Truncating the instant returns a copy of the original with fields
smaller than the specified unit set to zero.
The fields are calculated on the basis of using a UTC offset as seen
in toString.
For example, truncating with the MINUTES unit will
round down to the nearest minute, setting the seconds and nanoseconds to zero.
The unit must have a duration
that divides into the length of a standard day without remainder.
This includes all supplied time units on ChronoUnit and
DAYS. Other units throw an exception.
This instance is immutable and unaffected by this method call.
the unit to truncate to, not null
an { @code Instant} based on this instant with the time truncated, not null
DateTimeException if the unit is invalid for truncation
Calculates the period between this instant and another instant in terms of the specified unit.
Calculates the period between this instant and another instant in terms of the specified unit.
This calculates the period between two instants in terms of a single unit.
The start and end points are this and the specified instant.
The result will be negative if the end is before the start.
The calculation returns a whole number, representing the number of
complete units between the two instants.
The Temporal passed to this method is converted to a
Instant using #from(TemporalAccessor).
For example, the period in days between two dates can be calculated
using startInstant.until(endInstant, SECONDS).
This method operates in association with TemporalUnit#between.
The result of this method is a long representing the amount of
the specified unit. By contrast, the result of between is an
object that can be used directly in addition/subtraction:
long period = start.until(end, SECONDS); // this method dateTime.plus(SECONDS.between(start, end)); // use in plus/minus
The calculation is implemented in this method for ChronoUnit.
The units NANOS, MICROS, MILLIS, SECONDS,
MINUTES, HOURS, HALF_DAYS and DAYS
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 input temporal as
the second argument.
This instance is immutable and unaffected by this method call.
the end date, which is converted to an { @code Instant}, not null
the unit to measure the period in, not null
the amount of the period between this date and the end date
ArithmeticException if numeric overflow occurs
DateTimeException if the period cannot be calculated
Returns a copy of this instant with the specified field set to a new value.
Returns a copy of this instant with the specified field set to a new value.
This returns a new Instant, 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:
NANO_OF_SECOND -
Returns an Instant with the specified nano-of-second.
The epoch-second will be unchanged.MICRO_OF_SECOND -
Returns an Instant with the nano-of-second replaced by the specified
micro-of-second multiplied by 1,000. The epoch-second will be unchanged.MILLI_OF_SECOND -
Returns an Instant with the nano-of-second replaced by the specified
milli-of-second multiplied by 1,000,000. The epoch-second will be unchanged.INSTANT_SECONDS -
Returns an Instant with the specified epoch-second.
The nano-of-second 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 a DateTimeException.
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.
the field to set in the result, not null
the new value of the field in the result
an { @code Instant} based on { @code this} with the specified field set, not null
ArithmeticException if numeric overflow occurs
DateTimeException if the field cannot be set
Returns an adjusted copy of this instant.
Returns an adjusted copy of this instant.
This returns a new Instant, based on this one, with the date 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.
the adjuster to use, not null
an { @code Instant} based on { @code this} with the adjustment made, not null
ArithmeticException if numeric overflow occurs
DateTimeException if the adjustment cannot be made
An instantaneous point on the time-line.
This class models a single instantaneous point on the time-line. This might be used to record event time-stamps in the application.
For practicality, the instant is stored with some constraints. The measurable time-line is restricted to the number of seconds that can be held in a
long. This is greater than the current estimated age of the universe. The instant is stored to nanosecond resolution.The range of an instant requires the storage of a number larger than a
long. To achieve this, the class stores alongrepresenting epoch-seconds and anintrepresenting nanosecond-of-second, which will always be between 0 and 999,999,999. The epoch-seconds are measured from the standard Java epoch of1970-01-01T00:00:00Zwhere instants after the epoch have positive values, and earlier instants have negative values. For both the epoch-second and nanosecond parts, a larger value is always later on the time-line than a smaller value.Time-scale
The length of the solar day is the standard way that humans measure time. This has traditionally been subdivided into 24 hours of 60 minutes of 60 seconds, forming a 86400 second day.
Modern timekeeping is based on atomic clocks which precisely define an SI second relative to the transitions of a Caesium atom. The length of an SI second was defined to be very close to the 86400th fraction of a day.
Unfortunately, as the Earth rotates the length of the day varies. In addition, over time the average length of the day is getting longer as the Earth slows. As a result, the length of a solar day in 2012 is slightly longer than 86400 SI seconds. The actual length of any given day and the amount by which the Earth is slowing are not predictable and can only be determined by measurement. The UT1 time-scale captures the accurate length of day, but is only available some time after the day has completed.
The UTC time-scale is a standard approach to bundle up all the additional fractions of a second from UT1 into whole seconds, known as leap-seconds. A leap-second may be added or removed depending on the Earth's rotational changes. As such, UTC permits a day to have 86399 SI seconds or 86401 SI seconds where necessary in order to keep the day aligned with the Sun.
The modern UTC time-scale was introduced in 1972, introducing the concept of whole leap-seconds. Between 1958 and 1972, the definition of UTC was complex, with minor sub-second leaps and alterations to the length of the notional second. As of 2012, discussions are underway to change the definition of UTC again, with the potential to remove leap seconds or introduce other changes.
Given the complexity of accurate timekeeping described above, this Java API defines its own time-scale with a simplification. The Java time-scale is defined as follows:
Agreed international civil time is the base time-scale agreed by international convention, which in 2012 is UTC (with leap-seconds).
In 2012, the definition of the Java time-scale is the same as UTC for all days except those where a leap-second occurs. On days where a leap-second does occur, the time-scale effectively eliminates the leap-second, maintaining the fiction of 86400 seconds in the day.
The main benefit of always dividing the day into 86400 subdivisions is that it matches the expectations of most users of the API. The alternative is to force every user to understand what a leap second is and to force them to have special logic to handle them. Most applications do not have access to a clock that is accurate enough to record leap-seconds. Most applications also do not have a problem with a second being a very small amount longer or shorter than a real SI second during a leap-second.
If an application does have access to an accurate clock that reports leap-seconds, then the recommended technique to implement the Java time-scale is to use the UTC-SLS convention. UTC-SLS effectively smoothes the leap-second over the last 1000 seconds of the day, making each of the last 1000 "seconds" 1/1000th longer or shorter than a real SI second.
One final problem is the definition of the agreed international civil time before the introduction of modern UTC in 1972. This includes the Java epoch of
1970-01-01. It is intended that instants before 1972 be interpreted based on the solar day divided into 86400 subdivisions.The Java time-scale is used by all date-time classes. This includes
Instant,LocalDate,LocalTime,OffsetDateTime,ZonedDateTimeandDuration.Specification for implementors
This class is immutable and thread-safe.
Constructs an instance of
Instantusing seconds from the epoch of 1970-01-01T00:00:00Z and nanosecond fraction of second.