IChronology Interface

Definition

[Android.Runtime.Register("java/time/chrono/Chronology", "", "Java.Time.Chrono.IChronologyInvoker", ApiSince=26)]
public interface IChronology : IDisposable, Java.Interop.IJavaPeerable, Java.Lang.IComparable

[<Android.Runtime.Register("java/time/chrono/Chronology", "", "Java.Time.Chrono.IChronologyInvoker", ApiSince=26)>]
type IChronology = interface
    interface IComparable
    interface IJavaObject
    interface IDisposable
    interface IJavaPeerable

Derived

Java.Time.Chrono.AbstractChronology

Attributes

RegisterAttribute

Implements

IJavaObject IJavaPeerable IComparable IDisposable

Remarks

A calendar system, used to organize and identify dates.

The main date and time API is built on the ISO calendar system. The chronology operates behind the scenes to represent the general concept of a calendar system. For example, the Japanese, Taiwan Calendar, Thai Buddhist and others.

Most other calendar systems also operate on the shared concepts of year, month and day, linked to the cycles of the Earth around the Sun, and the Moon around the Earth. These shared concepts are defined by ChronoField and are available for use by any Chronology implementation:

LocalDate isoDate = ...
              ThaiBuddhistDate thaiDate = ...
              int isoYear = isoDate.get(ChronoField.YEAR);
              int thaiYear = thaiDate.get(ChronoField.YEAR);

As shown, although the date objects are in different calendar systems, represented by different Chronology instances, both can be queried using the same constant on ChronoField. For a full discussion of the implications of this, see ChronoLocalDate. In general, the advice is to use the known ISO-based LocalDate, rather than ChronoLocalDate.

While a Chronology object typically uses ChronoField and is based on an era, year-of-era, month-of-year, day-of-month model of a date, this is not required. A Chronology instance may represent a totally different kind of calendar system, such as the Mayan.

In practical terms, the Chronology instance also acts as a factory. The #of(String) method allows an instance to be looked up by identifier, while the #ofLocale(Locale) method allows lookup by locale.

The Chronology instance provides a set of methods to create ChronoLocalDate instances. The date classes are used to manipulate specific dates. <ul> <li> #dateNow() dateNow()<li> #dateNow(Clock) dateNow(clock)<li> #dateNow(ZoneId) dateNow(zone)<li> #date(int, int, int) date(yearProleptic, month, day)<li> #date(Era, int, int, int) date(era, yearOfEra, month, day)<li> #dateYearDay(int, int) dateYearDay(yearProleptic, dayOfYear)<li> #dateYearDay(Era, int, int) dateYearDay(era, yearOfEra, dayOfYear)<li> #date(TemporalAccessor) date(TemporalAccessor)</ul>

<h2 id="addcalendars">Adding New Calendars</h2> The set of available chronologies can be extended by applications. Adding a new calendar system requires the writing of an implementation of Chronology, ChronoLocalDate and Era. The majority of the logic specific to the calendar system will be in the ChronoLocalDate implementation. The Chronology implementation acts as a factory.

To permit the discovery of additional chronologies, the java.util.ServiceLoader ServiceLoader is used. A file must be added to the META-INF/services directory with the name 'java.time.chrono.Chronology' listing the implementation classes. See the ServiceLoader for more details on service loading. For lookup by id or calendarType, the system provided calendars are found first followed by application provided calendars.

Each chronology must define a chronology ID that is unique within the system. If the chronology represents a calendar system defined by the CLDR specification then the calendar type is the concatenation of the CLDR type and, if applicable, the CLDR variant.

Added in 1.8.

Java documentation for java.time.chrono.Chronology.

Portions of this page are modifications based on work created and shared by the Android Open Source Project and used according to terms described in the Creative Commons 2.5 Attribution License.

Properties

Methods

Extension Methods

Applies to