org.threeten.bp
Class Instant

java.lang.Object
  org.threeten.bp.jdk8.DefaultInterfaceTemporalAccessor
      org.threeten.bp.Instant

All Implemented Interfaces:

Serializable, Comparable<Instant>, Temporal, TemporalAccessor, TemporalAdjuster

public final class Instant
extends DefaultInterfaceTemporalAccessor
implements Temporal, TemporalAdjuster, Comparable<Instant>, Serializable

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 a long representing epoch-seconds and an int representing nanosecond-of-second, which will always be between 0 and 999,999,999. The epoch-seconds are measured from the standard Java epoch of 1970-01-01T00:00:00Z where 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:

• midday will always be exactly as defined by the agreed international civil time
• other times during the day will be broadly in line with the agreed international civil time
• the day will be divided into exactly 86400 subdivisions, referred to as "seconds"
• the Java "second" may differ from an SI second

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, ZonedDateTime and Duration.

Specification for implementors

See Also:

Serialized Form

EPOCH

public static final Instant EPOCH

Constant for the 1970-01-01T00:00:00Z epoch instant.

MIN

public static final Instant MIN

The minimum supported Instant, '-1000000000-01-01T00:00Z'. This could be used by an application as a "far past" instant.

This is one year earlier than the minimum LocalDateTime. This provides sufficient values to handle the range of ZoneOffset which affect the instant in addition to the local date-time. The value is also chosen such that the value of the year fits in an int.

MAX

public static final Instant MAX

The maximum supported Instant, '1000000000-12-31T23:59:59.999999999Z'. This could be used by an application as a "far future" instant.

This is one year later than the maximum LocalDateTime. This provides sufficient values to handle the range of ZoneOffset which affect the instant in addition to the local date-time. The value is also chosen such that the value of the year fits in an int.

FROM

public static final TemporalQuery<Instant> FROM

Simulate JDK 8 method reference Instant::from.

now

public static Instant now()

Obtains the current instant from the system clock.

This will query the system UTC clock to obtain the current instant.

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

Returns:

the current instant using the system clock, not null

now

public static Instant now(Clock clock)

Obtains the current instant from the specified clock.

This will query the specified clock to obtain the current time.

Using this method allows the use of an alternate clock for testing. The alternate clock may be introduced using dependency injection.

Parameters:

clock - the clock to use, not null

Returns:

the current instant, not null

ofEpochSecond

public static Instant ofEpochSecond(long epochSecond)

Obtains an instance of Instant using seconds from the epoch of 1970-01-01T00:00:00Z.

The nanosecond field is set to zero.

Parameters:

epochSecond - the number of seconds from 1970-01-01T00:00:00Z

Returns:

an instant, not null

Throws:

DateTimeException - if the instant exceeds the maximum or minimum instant

ofEpochSecond

public static Instant ofEpochSecond(long epochSecond,
                                    long nanoAdjustment)

Obtains an instance of Instant using seconds from the epoch of 1970-01-01T00:00:00Z and nanosecond fraction of second.

This method allows an arbitrary number of nanoseconds to be passed in. The factory will alter the values of the second and nanosecond in order to ensure that the stored nanosecond is in the range 0 to 999,999,999. For example, the following will result in the exactly the same instant:

  Instant.ofSeconds(3, 1);
  Instant.ofSeconds(4, -999_999_999);
  Instant.ofSeconds(2, 1000_000_001);
 

Parameters:

epochSecond - the number of seconds from 1970-01-01T00:00:00Z

nanoAdjustment - the nanosecond adjustment to the number of seconds, positive or negative

Returns:

an instant, not null

Throws:

DateTimeException - if the instant exceeds the maximum or minimum instant

ArithmeticException - if numeric overflow occurs

ofEpochMilli

public static Instant ofEpochMilli(long epochMilli)

Obtains an instance of Instant using milliseconds from the epoch of 1970-01-01T00:00:00Z.

The seconds and nanoseconds are extracted from the specified milliseconds.

Parameters:

epochMilli - the number of milliseconds from 1970-01-01T00:00:00Z

Returns:

an instant, not null

Throws:

DateTimeException - if the instant exceeds the maximum or minimum instant

from

public static Instant from(TemporalAccessor temporal)

Obtains an instance of Instant 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 Instant.

The conversion extracts the INSTANT_SECONDS and NANO_OF_SECOND fields.

This method matches the signature of the functional interface TemporalQuery allowing it to be used as a query via method reference, Instant::from.

Parameters:

temporal - the temporal object to convert, not null

Returns:

the instant, not null

Throws:

DateTimeException - if unable to convert to an Instant

parse

public static Instant parse(CharSequence text)

Obtains an instance of Instant from a text string such as 2007-12-03T10:15:30.000Z.

The string must represent a valid instant in UTC and is parsed using DateTimeFormatter.ISO_INSTANT.

Parameters:

text - the text to parse, not null

Returns:

the parsed instant, not null

Throws:

DateTimeParseException - if the text cannot be parsed

isSupported

public boolean isSupported(TemporalField field)

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_SECOND
• MICRO_OF_SECOND
• MILLI_OF_SECOND
• INSTANT_SECONDS

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

Specified by:

isSupported in interface TemporalAccessor

Parameters:

field - the field to check, null returns false

Returns:

true if the field is supported on this instant, false if not

isSupported

public boolean isSupported(TemporalUnit unit)

Description copied from interface: Temporal

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.

Specified by:

isSupported in interface Temporal

Parameters:

unit - the unit to check, null returns false

Returns:

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

range

public ValueRange range(TemporalField 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.

Specified by:

range in interface TemporalAccessor

Overrides:

range in class DefaultInterfaceTemporalAccessor

Parameters:

field - the field to query the range for, not null

Returns:

the range of valid values for the field, not null

Throws:

DateTimeException - if the range for the field cannot be obtained

get

public int get(TemporalField field)

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.

Specified by:

get in interface TemporalAccessor

Overrides:

get in class DefaultInterfaceTemporalAccessor

Parameters:

field - the field to get, not null

Returns:

the value for the field

Throws:

DateTimeException - if a value for the field cannot be obtained

ArithmeticException - if numeric overflow occurs

getLong

public long getLong(TemporalField field)

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.

Specified by:

getLong in interface TemporalAccessor

Parameters:

field - the field to get, not null

Returns:

the value for the field

Throws:

DateTimeException - if a value for the field cannot be obtained

ArithmeticException - if numeric overflow occurs

getEpochSecond

public long getEpochSecond()

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.

Returns:

the seconds from the epoch of 1970-01-01T00:00:00Z

getNano

public int getNano()

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.

Returns:

the nanoseconds within the second, always positive, never exceeds 999,999,999

with

public Instant with(TemporalAdjuster adjuster)

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.

Specified by:

with in interface Temporal

Parameters:

adjuster - the adjuster to use, not null

Returns:

an Instant based on this with the adjustment made, not null

Throws:

DateTimeException - if the adjustment cannot be made

ArithmeticException - if numeric overflow occurs

with

public Instant with(TemporalField field,
                    long newValue)

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.

Specified by:

with in interface Temporal

Parameters:

field - the field to set in the result, not null

newValue - the new value of the field in the result

Returns:

an Instant based on this with the specified field set, not null

Throws:

DateTimeException - if the field cannot be set

ArithmeticException - if numeric overflow occurs

truncatedTo

public Instant truncatedTo(TemporalUnit 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.

Parameters:

unit - the unit to truncate to, not null

Returns:

an Instant based on this instant with the time truncated, not null

Throws:

DateTimeException - if the unit is invalid for truncation

plus

public Instant plus(TemporalAmount amount)

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.

Specified by:

plus in interface Temporal

Parameters:

amount - the amount to add, not null

Returns:

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

Throws:

DateTimeException - if the addition cannot be made

ArithmeticException - if numeric overflow occurs

plus

public Instant plus(long amountToAdd,
                    TemporalUnit unit)

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.

Specified by:

plus in interface Temporal

Parameters:

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

unit - the unit of the period to add, not null

Returns:

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

Throws:

DateTimeException - if the unit cannot be added

ArithmeticException - if numeric overflow occurs

plusSeconds

public Instant plusSeconds(long secondsToAdd)

Returns a copy of this instant with the specified duration in seconds added.

This instance is immutable and unaffected by this method call.

Parameters:

secondsToAdd - the seconds to add, positive or negative

Returns:

an Instant based on this instant with the specified seconds added, not null

Throws:

DateTimeException - if the result exceeds the maximum or minimum instant

ArithmeticException - if numeric overflow occurs

plusMillis

public Instant plusMillis(long millisToAdd)

Returns a copy of this instant with the specified duration in milliseconds added.

This instance is immutable and unaffected by this method call.

Parameters:

millisToAdd - the milliseconds to add, positive or negative

Returns:

an Instant based on this instant with the specified milliseconds added, not null

Throws:

DateTimeException - if the result exceeds the maximum or minimum instant

ArithmeticException - if numeric overflow occurs

plusNanos

public Instant plusNanos(long nanosToAdd)

Returns a copy of this instant with the specified duration in nanoseconds added.

This instance is immutable and unaffected by this method call.

Parameters:

nanosToAdd - the nanoseconds to add, positive or negative

Returns:

an Instant based on this instant with the specified nanoseconds added, not null

Throws:

DateTimeException - if the result exceeds the maximum or minimum instant

ArithmeticException - if numeric overflow occurs

minus

public Instant minus(TemporalAmount amount)

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.

Specified by:

minus in interface Temporal

Parameters:

amount - the amount to subtract, not null

Returns:

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

Throws:

DateTimeException - if the subtraction cannot be made

ArithmeticException - if numeric overflow occurs

minus

public Instant minus(long amountToSubtract,
                     TemporalUnit unit)

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.

Specified by:

minus in interface Temporal

Parameters:

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

unit - the unit of the period to subtract, not null

Returns:

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

Throws:

DateTimeException - if the unit cannot be subtracted

ArithmeticException - if numeric overflow occurs

minusSeconds

public Instant minusSeconds(long secondsToSubtract)

Returns a copy of this instant with the specified duration in seconds subtracted.

This instance is immutable and unaffected by this method call.

Parameters:

secondsToSubtract - the seconds to subtract, positive or negative

Returns:

an Instant based on this instant with the specified seconds subtracted, not null

Throws:

DateTimeException - if the result exceeds the maximum or minimum instant

ArithmeticException - if numeric overflow occurs

minusMillis

public Instant minusMillis(long millisToSubtract)

Returns a copy of this instant with the specified duration in milliseconds subtracted.

This instance is immutable and unaffected by this method call.

Parameters:

millisToSubtract - the milliseconds to subtract, positive or negative

Returns:

an Instant based on this instant with the specified milliseconds subtracted, not null

Throws:

DateTimeException - if the result exceeds the maximum or minimum instant

ArithmeticException - if numeric overflow occurs

minusNanos

public Instant minusNanos(long nanosToSubtract)

Returns a copy of this instant with the specified duration in nanoseconds subtracted.

This instance is immutable and unaffected by this method call.

Parameters:

nanosToSubtract - the nanoseconds to subtract, positive or negative

Returns:

an Instant based on this instant with the specified nanoseconds subtracted, not null

Throws:

DateTimeException - if the result exceeds the maximum or minimum instant

ArithmeticException - if numeric overflow occurs

query

public <R> R query(TemporalQuery<R> 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.

Specified by:

query in interface TemporalAccessor

Overrides:

query in class DefaultInterfaceTemporalAccessor

Type Parameters:

R - the type of the result

Parameters:

query - the query to invoke, not null

Returns:

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

Throws:

DateTimeException - if unable to query (defined by the query)

ArithmeticException - if numeric overflow occurs (defined by the query)

adjustInto

public Temporal adjustInto(Temporal temporal)

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 Temporal.with(TemporalField, 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.

Specified by:

adjustInto in interface TemporalAdjuster

Parameters:

temporal - the target object to be adjusted, not null

Returns:

the adjusted object, not null

Throws:

DateTimeException - if unable to make the adjustment

ArithmeticException - if numeric overflow occurs

until

public long until(Temporal endExclusive,
                  TemporalUnit 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(org.threeten.bp.temporal.Temporal, org.threeten.bp.temporal.Temporal). 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.

Specified by:

until in interface Temporal

Parameters:

endExclusive - the end date, which is converted to an Instant, not null

unit - the unit to measure the period in, not null

Returns:

the amount of the period between this date and the end date

Throws:

DateTimeException - if the period cannot be calculated

ArithmeticException - if numeric overflow occurs

atOffset

public OffsetDateTime atOffset(ZoneOffset offset)

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 OffsetDateTime.ofInstant(this, offset).

Parameters:

offset - the offset to combine with, not null

Returns:

the offset date-time formed from this instant and the specified offset, not null

Throws:

DateTimeException - if the result exceeds the supported range

atZone

public ZonedDateTime atZone(ZoneId zone)

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 ZonedDateTime.ofInstant(this, zone).

Parameters:

zone - the zone to combine with, not null

Returns:

the zoned date-time formed from this instant and the specified zone, not null

Throws:

DateTimeException - if the result exceeds the supported range

toEpochMilli

public long toEpochMilli()

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.

Returns:

the number of milliseconds since the epoch of 1970-01-01T00:00:00Z

Throws:

ArithmeticException - if numeric overflow occurs

compareTo

public int compareTo(Instant otherInstant)

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.

Specified by:

compareTo in interface Comparable<Instant>

Parameters:

otherInstant - the other instant to compare to, not null

Returns:

the comparator value, negative if less, positive if greater

Throws:

NullPointerException - if otherInstant is null

isAfter

public boolean isAfter(Instant otherInstant)

Checks if this instant is after the specified instant.

The comparison is based on the time-line position of the instants.

Parameters:

otherInstant - the other instant to compare to, not null

Returns:

true if this instant is after the specified instant

Throws:

NullPointerException - if otherInstant is null

isBefore

public boolean isBefore(Instant otherInstant)

Checks if this instant is before the specified instant.

The comparison is based on the time-line position of the instants.

Parameters:

otherInstant - the other instant to compare to, not null

Returns:

true if this instant is before the specified instant

Throws:

NullPointerException - if otherInstant is null

equals

public boolean equals(Object otherInstant)

Checks if this instant is equal to the specified instant.

The comparison is based on the time-line position of the instants.

Overrides:

equals in class Object

Parameters:

otherInstant - the other instant, null returns false

Returns:

true if the other instant is equal to this one

hashCode

public int hashCode()

Returns a hash code for this instant.

Overrides:

hashCode in class Object

Returns:

a suitable hash code

toString

public String toString()

A string representation of this instant using ISO-8601 representation.

The format used is the same as DateTimeFormatter.ISO_INSTANT.

Overrides:

toString in class Object

Returns:

an ISO-8601 representation of this instant, not null