Packages

Definition Classes: root

Definition Classes: root

Definition Classes: org

package bp

The main API for dates, times, instants, and durations.

The classes defined here represent the principal date-time concepts, including instants, durations, dates, times, time-zones and periods. They are based on the ISO calendar system, which is the de facto world calendar following the proleptic Gregorian rules. All the classes are immutable and thread-safe.

Each date time instance is composed of fields that are conveniently made available by the APIs. For lower level access to the fields refer to the org.threeten.bp.temporal package. Each class includes support for printing and parsing all manner of dates and times. Refer to the org.threeten.bp.format package for customization options.

The org.threeten.bp.chrono package contains the calendar neutral API. This is intended for use by applications that need to use localized calendars. It is recommended that applications use the ISO-8601 dates and time classes from this package across system boundaries, such as to the database or across the network. The calendar neutral API should be reserved for interactions with users.

Dates and Times

org.threeten.bp.Instant is essentially a numeric timestamp. The current Instant can be retrieved from a org.threeten.bp.Clock. This is useful for logging and persistence of a point in time and has in the past been associated with storing the result from java.lang.System#currentTimeMillis().

org.threeten.bp.LocalDate stores a date without a time. This stores a date like '2010-12-03' and could be used to store a birthday.

org.threeten.bp.LocalTime stores a time without a date. This stores a time like '11:30' and could be used to store an opening or closing time.

org.threeten.bp.LocalDateTime stores a date and time. This stores a date-time like '2010-12-03T11:30'.

org.threeten.bp.OffsetTime stores a time and offset from UTC without a date. This stores a date like '11:30+01:00'. The ZoneOffset is of the form '+01:00'.

org.threeten.bp.OffsetDateTime stores a date and time and offset from UTC. This stores a date-time like '2010-12-03T11:30+01:00'. This is sometimes found in XML messages and other forms of persistence, but contains less information than a full time-zone.

org.threeten.bp.ZonedDateTime stores a date and time with a time-zone. This is useful if you want to perform accurate calculations of dates and times taking into account the org.threeten.bp.ZoneId, such as 'Europe/Paris'. Where possible, it is recommended to use a simpler class. The widespread use of time-zones tends to add considerable complexity to an application.

Duration and Period

Beyond dates and times, the API also allows the storage of period and durations of time. A org.threeten.bp.Duration is a simple measure of time along the time-line in nanoseconds. A org.threeten.bp.Period expresses an amount of time in units meaningful to humans, such as years or hours.

Additional value types

org.threeten.bp.Year stores a year on its own. This stores a single year in isolation, such as '2010'.

org.threeten.bp.YearMonth stores a year and month without a day or time. This stores a year and month, such as '2010-12' and could be used for a credit card expiry.

org.threeten.bp.MonthDay stores a month and day without a year or time. This stores a month and day-of-month, such as '--12-03' and could be used to store an annual event like a birthday without storing the year.

org.threeten.bp.Month stores a month on its own. This stores a single month-of-year in isolation, such as 'DECEMBER'.

org.threeten.bp.DayOfWeek stores a day-of-week on its own. This stores a single day-of-week in isolation, such as 'TUESDAY'.

Definition Classes: threeten

package chrono

Support for calendar systems other than the default ISO.

The main API is based around the calendar system defined in ISO-8601. This package provides support for alternate systems.

The supported calendar systems includes:

-Hijrah calendar -Japanese calendar -Minguo calendar -Thai Buddhist calendar

It is intended that applications use the main API whenever possible, including code to read and write from a persistent data store, such as a database, and to send dates and times across a network. This package is then used at the user interface level to deal with localized input/output. See ChronoLocalDate for a full discussion of the issues.

Example

This example creates and uses a date in a non-ISO calendar system.

        // Print the Thai Buddhist date
        ChronoLocalDate now1 = ThaiBuddhistChronology.INSTANCE.now();
        int day = now1.get(ChronoField.DAY_OF_MONTH);
        int dow = now1.get(ChronoField.DAY_OF_WEEK);
        int month = now1.get(ChronoField.MONTH_OF_YEAR);
        int year = now1.get(ChronoField.YEAR);
        System.out.printf("  Today is %s %s %d-%s-%d%n", now1.getChronology().getId(),
                dow, day, month, year);

        // Enumerate the list of available calendars and print today for each
        Set<String> names = Chronology.getAvailableIds();
        for (String name : names) {
            Chronology<?> chrono = Chronology.of(name);
            ChronoLocalDate<?> date = chrono.now();
            System.out.printf("   %20s: %s%n", chrono.getId(), date.toString());
        }

        // Print today's date and the last day of the year for the Thai Buddhist Calendar.
        ChronoLocalDate first = now1
                .with(ChronoField.DAY_OF_MONTH, 1)
                .with(ChronoField.MONTH_OF_YEAR, 1);
        ChronoLocalDate last = first
                .plus(1, ChronoUnit.YEARS)
                .minus(1, ChronoUnit.DAYS);
        System.out.printf("  %s: 1st of year: %s; end of year: %s%n", last.getChronology().getId(),
                first, last);

Definition Classes: bp

package format

Provides classes to print and parse dates and times.

Printing and parsing is based around the DateTimeFormatter class. That class contains common formatters and factory methods. The DateTimeFormatterBuilder class is available for advanced and complex use cases.

Localization occurs by calling withLocale(Locale) on the formatter. Further customization is possible using DecimalStyle.

Definition Classes: bp

package temporal

Access to date and time using fields and units.

This package expands on the base package to provide additional functionality for more powerful use cases. Support is included for:

Units of date-time, such as years, months, days and hours
Fields of date-time, such as month-of-year, day-of-week or hour-of-day
Date-time adjustment functions
Different definitions of weeks

Fields and Units

Dates and times are expressed in terms of fields and units. A unit is used to measure an amount of time, such as years, days or minutes. All units implement org.threeten.bp.temporal.TemporalUnit. The set of well known units is defined in org.threeten.bp.temporal.ChronoUnit, for example, org.threeten.bp.temporal.ChronoUnit#DAYS. The unit interface is designed to allow applications to add their own units.

A field is used to express part of a larger date-time, such as year, month-of-year or second-of-minute. All fields implement org.threeten.bp.temporal.TemporalField. The set of well known fields are defined in org.threeten.bp.temporal.ChronoField, for example, org.threeten.bp.temporal.ChronoField#HOUR_OF_DAY. An additional fields are defined by org.threeten.bp.temporal.JulianFields. The field interface is designed to allow applications to add their own fields.

This package provides tools that allow the units and fields of date and time to be accessed in a general way most suited for frameworks. org.threeten.bp.temporal.Temporal provides the abstraction for date time types that support fields. Its methods support getting the value of a field, creating a new date time with the value of a field modified, and extracting another date time type, typically used to extract the offset or time-zone.

One use of fields in application code is to retrieve fields for which there is no convenience method. For example, getting the day-of-month is common enough that there is a method on LocalDate called getDayOfMonth(). However for more unusual fields it is necessary to use the field. For example, date.get(ChronoField.ALIGNED_WEEK_OF_MONTH). The fields also provide access to the range of valid values.

Adjustment

A key part of the date-time problem space is adjusting a date to a new, related value, such as the "last day of the month", or "next Wednesday". These are modeled as functions that adjust a base date-time. The functions implement org.threeten.bp.temporal.TemporalAdjuster and operate on org.threeten.bp.temporal.Temporal. A set of common functions are provided in org.threeten.bp.temporal.TemporalAdjusters. For example, to find the first occurrence of a day-of-week after a given date, use org.threeten.bp.temporal.TemporalAdjusters#next(DayOfWeek), such as date.with(next(MONDAY)).

Weeks

Different locales have different definitions of the week. For example, in Europe the week typically starts on a Monday, while in the US it starts on a Sunday. The org.threeten.bp.temporal.WeekFields class models this distinction.

The ISO calendar system defines an additional week-based division of years. This defines a year based on whole Monday to Monday weeks. This is modeled in org.threeten.bp.temporal.IsoFields.

Definition Classes: bp

package zone

Support for time-zones and their rules.

Daylight Saving Time and Time-Zones are concepts used by Governments to alter local time. This package provides support for time-zones, their rules and the resulting gaps and overlaps in the local time-line typically caused by Daylight Saving Time.

Definition Classes: bp

ZoneId

Companion object ZoneId

abstract class ZoneId extends Serializable

A time-zone ID, such as Europe/Paris.

A ZoneId is used to identify the rules used to convert between an Instant and a LocalDateTime. There are two distinct types of ID:

Fixed offsets - a fully resolved offset from UTC/Greenwich, that uses the same offset for all local date-times
Geographical regions - an area where a specific set of rules for finding the offset from UTC/Greenwich apply

Most fixed offsets are represented by ZoneOffset. Calling #normalized() on any ZoneId will ensure that a fixed offset ID will be represented as a ZoneOffset.

The actual rules, describing when and how the offset changes, are defined by ZoneRules. This class is simply an ID used to obtain the underlying rules. This approach is taken because rules are defined by governments and change frequently, whereas the ID is stable.

The distinction has other effects. Serializing the ZoneId will only send the ID, whereas serializing the rules sends the entire data set. Similarly, a comparison of two IDs only examines the ID, whereas a comparison of two rules examines the entire data set.

Time-zone IDs

The ID is unique within the system. There are three types of ID.

The simplest type of ID is that from ZoneOffset. This consists of 'Z' and IDs starting with '+' or '-'.

The next type of ID are offset-style IDs with some form of prefix, such as 'GMT+2' or 'UTC+01:00'. The recognised prefixes are 'UTC', 'GMT' and 'UT'. The offset is the suffix and will be normalized during creation. These IDs can be normalized to a ZoneOffset using normalized().

The third type of ID are region-based IDs. A region-based ID must be of two or more characters, and not start with 'UTC', 'GMT', 'UT' '+' or '-'. Region-based IDs are defined by configuration, see ZoneRulesProvider. The configuration focuses on providing the lookup from the ID to the underlying ZoneRules.

Time-zone rules are defined by governments and change frequently. There are a number of organizations, known here as groups, that monitor time-zone changes and collate them. The default group is the IANA Time Zone Database (TZDB). Other organizations include IATA (the airline industry body) and Microsoft.

Each group defines its own format for the region ID it provides. The TZDB group defines IDs such as 'Europe/London' or 'America/New_York'. TZDB IDs take precedence over other groups.

It is strongly recommended that the group name is included in all IDs supplied by groups other than TZDB to avoid conflicts. For example, IATA airline time-zone region IDs are typically the same as the three letter airport code. However, the airport of Utrecht has the code 'UTC', which is obviously a conflict. The recommended format for region IDs from groups other than TZDB is 'group~region'. Thus if IATA data were defined, Utrecht airport would be 'IATA~UTC'.

Serialization

This class can be serialized and stores the string zone ID in the external form. The ZoneOffset subclass uses a dedicated format that only stores the offset from UTC/Greenwich.

A ZoneId can be deserialized in a Java Runtime where the ID is unknown. For example, if a server-side Java Runtime has been updated with a new zone ID, but the client-side Java Runtime has not been updated. In this case, the ZoneId object will exist, and can be queried using getId, equals, hashCode, toString, getDisplayName and normalized. However, any call to getRules will fail with ZoneRulesException. This approach is designed to allow a ZonedDateTime to be loaded and queried, but not modified, on a Java Runtime with incomplete time-zone information.

Specification for implementors

This abstract class has two implementations, both of which are immutable and thread-safe. One implementation models region-based IDs, the other is ZoneOffset modelling offset-based IDs. This difference is visible in serialization.

Annotations: @SerialVersionUID()

Linear Supertypes

Serializable, AnyRef, Any

Known Subclasses

ZoneOffset, ZoneRegion

Ordering

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Inherited

ZoneId
Serializable
AnyRef
Any

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Visibility

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Protected

Abstract Value Members

abstract def getId: String
Gets the unique time-zone ID.
Gets the unique time-zone ID.
This ID uniquely defines this object. The format of an offset based ID is defined by ZoneOffset#getId().
returns
the time-zone unique ID, not null
abstract def getRules: ZoneRules
Gets the time-zone rules for this ID allowing calculations to be performed.
Gets the time-zone rules for this ID allowing calculations to be performed.
The rules provide the functionality associated with a time-zone, such as finding the offset for a given instant or local date-time.
A time-zone can be invalid if it is deserialized in a Java Runtime which does not have the same rules loaded as the Java Runtime that stored it. In this case, calling this method will throw a ZoneRulesException.
The rules are supplied by ZoneRulesProvider. An advanced provider may support dynamic updates to the rules without restarting the Java Runtime. If so, then the result of this method may change over time. Each individual call will be still remain thread-safe.
ZoneOffset will always return a set of rules where the offset never changes.
returns
the rules, not null
Exceptions thrown
ZoneRulesException if no rules are available for this ID

Concrete Value Members

final def !=(arg0: Any): Boolean
Definition Classes
AnyRef → Any
final def ##: Int
Definition Classes
AnyRef → Any
final def ==(arg0: Any): Boolean
Definition Classes
AnyRef → Any
final def asInstanceOf[T0]: T0
Definition Classes
Any
def clone(): AnyRef
Attributes
protected[lang]
Definition Classes
AnyRef
Annotations
@throws(classOf[java.lang.CloneNotSupportedException]) @native()
final def eq(arg0: AnyRef): Boolean
Definition Classes
AnyRef
def equals(obj: Any): Boolean
Checks if this time-zone ID is equal to another time-zone ID.
Checks if this time-zone ID is equal to another time-zone ID.
The comparison is based on the ID.
obj
the object to check, null returns false
returns
true if this is equal to the other time-zone ID
Definition Classes
ZoneId → AnyRef → Any
def finalize(): Unit
Attributes
protected[lang]
Definition Classes
AnyRef
Annotations
@throws(classOf[java.lang.Throwable])
final def getClass(): Class[_ <: AnyRef]
Definition Classes
AnyRef → Any
Annotations
@native()
def getDisplayName(style: TextStyle, locale: Locale): String
Gets the textual representation of the zone, such as 'British Time' or '+02:00'.
Gets the textual representation of the zone, such as 'British Time' or '+02:00'.
This returns the textual name used to identify the time-zone ID, suitable for presentation to the user. The parameters control the style of the returned text and the locale.
If no textual mapping is found then the full ID is returned.
style
the length of the text required, not null
locale
the locale to use, not null
returns
the text value of the zone, not null
def hashCode(): Int
A hash code for this time-zone ID.
A hash code for this time-zone ID.
returns
a suitable hash code
Definition Classes
ZoneId → AnyRef → Any
final def isInstanceOf[T0]: Boolean
Definition Classes
Any
final def ne(arg0: AnyRef): Boolean
Definition Classes
AnyRef
def normalized: ZoneId
Normalizes the time-zone ID, returning a ZoneOffset where possible.
Normalizes the time-zone ID, returning a ZoneOffset where possible.
The returns a normalized ZoneId that can be used in place of this ID. The result will have ZoneRules equivalent to those returned by this object, however the ID returned by getId() may be different.
The normalization checks if the rules of this ZoneId have a fixed offset. If they do, then the ZoneOffset equal to that offset is returned. Otherwise this is returned.
returns
the time-zone unique ID, not null
final def notify(): Unit
Definition Classes
AnyRef
Annotations
@native()
final def notifyAll(): Unit
Definition Classes
AnyRef
Annotations
@native()
final def synchronized[T0](arg0: => T0): T0
Definition Classes
AnyRef
def toString(): String
Outputs this zone as a String, using the ID.
Outputs this zone as a String, using the ID.
returns
a string representation of this time-zone ID, not null
Definition Classes
ZoneId → AnyRef → Any
final def wait(): Unit
Definition Classes
AnyRef
Annotations
@throws(classOf[java.lang.InterruptedException])
final def wait(arg0: Long, arg1: Int): Unit
Definition Classes
AnyRef
Annotations
@throws(classOf[java.lang.InterruptedException])
final def wait(arg0: Long): Unit
Definition Classes
AnyRef
Annotations
@throws(classOf[java.lang.InterruptedException]) @native()

Packages

Dates and Times

Duration and Period

Additional value types

Example

Fields and Units

Adjustment

Weeks

ZoneId

Companion object ZoneId

abstract class ZoneId extends Serializable

Time-zone IDs

Serialization

Specification for implementors

Abstract Value Members

Concrete Value Members

Inherited from Serializable

Inherited from AnyRef

Inherited from Any

Ungrouped

Packages

Dates and Times

Duration and Period

Additional value types

Example

Fields and Units

Adjustment

Weeks

ZoneId

Companion object ZoneId

abstract class ZoneId extends Serializable

Time-zone IDs

Serialization

Specification for implementors

Abstract Value Members

Concrete Value Members

Inherited from Serializable

Inherited from AnyRef

Inherited from Any

Ungrouped

ZoneId