Added in [API level 26](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels) Summary: [Protected Ctors](https://developer.android.com/reference/java/time/chrono/AbstractChronology#proctors) \| [Methods](https://developer.android.com/reference/java/time/chrono/AbstractChronology#pubmethods) \| [Inherited Methods](https://developer.android.com/reference/java/time/chrono/AbstractChronology#inhmethods)

# AbstractChronology


`
public


abstract
class
AbstractChronology
`


`

extends https://developer.android.com/reference/java/lang/Object


`

`


implements

https://developer.android.com/reference/java/time/chrono/Chronology


`

|---|---|
| [java.lang.Object](https://developer.android.com/reference/java/lang/Object) ||
| ↳ | java.time.chrono.AbstractChronology |

Known direct subclasses [HijrahChronology](https://developer.android.com/reference/java/time/chrono/HijrahChronology), [IsoChronology](https://developer.android.com/reference/java/time/chrono/IsoChronology), [JapaneseChronology](https://developer.android.com/reference/java/time/chrono/JapaneseChronology), [MinguoChronology](https://developer.android.com/reference/java/time/chrono/MinguoChronology), [ThaiBuddhistChronology](https://developer.android.com/reference/java/time/chrono/ThaiBuddhistChronology) [HijrahChronology](https://developer.android.com/reference/java/time/chrono/HijrahChronology) The Hijrah calendar is a lunar calendar supporting Islamic calendars. [IsoChronology](https://developer.android.com/reference/java/time/chrono/IsoChronology) The ISO calendar system. [JapaneseChronology](https://developer.android.com/reference/java/time/chrono/JapaneseChronology) The Japanese Imperial calendar system. [MinguoChronology](https://developer.android.com/reference/java/time/chrono/MinguoChronology) The Minguo calendar system. [ThaiBuddhistChronology](https://developer.android.com/reference/java/time/chrono/ThaiBuddhistChronology) The Thai Buddhist calendar system.   

*** ** * ** ***

An abstract implementation of 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.


See `https://developer.android.com/reference/java/time/chrono/Chronology` for more details.

## Summary

| ### Protected constructors ||
|---|---|
| ` https://developer.android.com/reference/java/time/chrono/AbstractChronology#AbstractChronology()() ` Creates an instance. |

| ### Public methods ||
|---|---|
| ` int` | ` https://developer.android.com/reference/java/time/chrono/AbstractChronology#compareTo(java.time.chrono.Chronology)(https://developer.android.com/reference/java/time/chrono/Chronology other) ` Compares this chronology to another chronology. |
| ` boolean` | ` https://developer.android.com/reference/java/time/chrono/AbstractChronology#equals(java.lang.Object)(https://developer.android.com/reference/java/lang/Object obj) ` Checks if this chronology is equal to another chronology. |
| ` int` | ` https://developer.android.com/reference/java/time/chrono/AbstractChronology#hashCode()() ` A hash code for this chronology. |
| ` https://developer.android.com/reference/java/time/chrono/ChronoLocalDate` | ` https://developer.android.com/reference/java/time/chrono/AbstractChronology#resolveDate(java.util.Map<java.time.temporal.TemporalField,java.lang.Long>,%20java.time.format.ResolverStyle)(https://developer.android.com/reference/java/util/Map<https://developer.android.com/reference/java/time/temporal/TemporalField, https://developer.android.com/reference/java/lang/Long> fieldValues, https://developer.android.com/reference/java/time/format/ResolverStyle resolverStyle) ` Resolves parsed `ChronoField` values into a date during parsing. |
| ` https://developer.android.com/reference/java/lang/String` | ` https://developer.android.com/reference/java/time/chrono/AbstractChronology#toString()() ` Outputs this chronology as a `String`, using the chronology ID. |

### Inherited methods

From class `

https://developer.android.com/reference/java/lang/Object

` `


https://developer.android.com/reference/java/lang/Object` `
https://developer.android.com/reference/java/lang/Object#clone()()
`

Creates and returns a copy of this object.


`


boolean` `
https://developer.android.com/reference/java/lang/Object#equals(java.lang.Object)(https://developer.android.com/reference/java/lang/Object obj)
`

Indicates whether some other object is "equal to" this one.


`


void` `
https://developer.android.com/reference/java/lang/Object#finalize()()
`

Called by the garbage collector on an object when garbage collection
determines that there are no more references to the object.


`


final

https://developer.android.com/reference/java/lang/Class<?>` `
https://developer.android.com/reference/java/lang/Object#getClass()()
`

Returns the runtime class of this `Object`.


`


int` `
https://developer.android.com/reference/java/lang/Object#hashCode()()
`

Returns a hash code value for the object.


`


final

void` `
https://developer.android.com/reference/java/lang/Object#notify()()
`

Wakes up a single thread that is waiting on this object's
monitor.


`


final

void` `
https://developer.android.com/reference/java/lang/Object#notifyAll()()
`

Wakes up all threads that are waiting on this object's monitor.


`


https://developer.android.com/reference/java/lang/String` `
https://developer.android.com/reference/java/lang/Object#toString()()
`

Returns a string representation of the object.


`


final

void` `
https://developer.android.com/reference/java/lang/Object#wait(long,%20int)(long timeoutMillis, int nanos)
`

Causes the current thread to wait until it is awakened, typically
by being *notified* or *interrupted*, or until a
certain amount of real time has elapsed.


`


final

void` `
https://developer.android.com/reference/java/lang/Object#wait(long)(long timeoutMillis)
`

Causes the current thread to wait until it is awakened, typically
by being *notified* or *interrupted*, or until a
certain amount of real time has elapsed.


`


final

void` `
https://developer.android.com/reference/java/lang/Object#wait()()
`

Causes the current thread to wait until it is awakened, typically
by being *notified* or *interrupted*.


From interface `

https://developer.android.com/reference/java/time/chrono/Chronology

` `
abstract


int` `
https://developer.android.com/reference/java/time/chrono/Chronology#compareTo(java.time.chrono.Chronology)(https://developer.android.com/reference/java/time/chrono/Chronology other)
`

Compares this chronology to another chronology.


`

default


https://developer.android.com/reference/java/time/chrono/ChronoLocalDate` `
https://developer.android.com/reference/java/time/chrono/Chronology#date(java.time.chrono.Era,%20int,%20int,%20int)(https://developer.android.com/reference/java/time/chrono/Era era, int yearOfEra, int month, int dayOfMonth)
`

Obtains a local date in this chronology from the era, year-of-era,
month-of-year and day-of-month fields.


`
abstract


https://developer.android.com/reference/java/time/chrono/ChronoLocalDate` `
https://developer.android.com/reference/java/time/chrono/Chronology#date(int,%20int,%20int)(int prolepticYear, int month, int dayOfMonth)
`

Obtains a local date in this chronology from the proleptic-year,
month-of-year and day-of-month fields.


`
abstract


https://developer.android.com/reference/java/time/chrono/ChronoLocalDate` `
https://developer.android.com/reference/java/time/chrono/Chronology#date(java.time.temporal.TemporalAccessor)(https://developer.android.com/reference/java/time/temporal/TemporalAccessor temporal)
`

Obtains a local date in this chronology from another temporal object.


`
abstract


https://developer.android.com/reference/java/time/chrono/ChronoLocalDate` `
https://developer.android.com/reference/java/time/chrono/Chronology#dateEpochDay(long)(long epochDay)
`

Obtains a local date in this chronology from the epoch-day.


`

default


https://developer.android.com/reference/java/time/chrono/ChronoLocalDate` `
https://developer.android.com/reference/java/time/chrono/Chronology#dateNow(java.time.Clock)(https://developer.android.com/reference/java/time/Clock clock)
`

Obtains the current local date in this chronology from the specified clock.


`

default


https://developer.android.com/reference/java/time/chrono/ChronoLocalDate` `
https://developer.android.com/reference/java/time/chrono/Chronology#dateNow(java.time.ZoneId)(https://developer.android.com/reference/java/time/ZoneId zone)
`

Obtains the current local date in this chronology from the system clock in the specified time-zone.


`

default


https://developer.android.com/reference/java/time/chrono/ChronoLocalDate` `
https://developer.android.com/reference/java/time/chrono/Chronology#dateNow()()
`

Obtains the current local date in this chronology from the system clock in the default time-zone.


`

default


https://developer.android.com/reference/java/time/chrono/ChronoLocalDate` `
https://developer.android.com/reference/java/time/chrono/Chronology#dateYearDay(java.time.chrono.Era,%20int,%20int)(https://developer.android.com/reference/java/time/chrono/Era era, int yearOfEra, int dayOfYear)
`

Obtains a local date in this chronology from the era, year-of-era and
day-of-year fields.


`
abstract


https://developer.android.com/reference/java/time/chrono/ChronoLocalDate` `
https://developer.android.com/reference/java/time/chrono/Chronology#dateYearDay(int,%20int)(int prolepticYear, int dayOfYear)
`

Obtains a local date in this chronology from the proleptic-year and
day-of-year fields.


`

default


long` `
https://developer.android.com/reference/java/time/chrono/Chronology#epochSecond(int,%20int,%20int,%20int,%20int,%20int,%20java.time.ZoneOffset)(int prolepticYear, int month, int dayOfMonth, int hour, int minute, int second, https://developer.android.com/reference/java/time/ZoneOffset zoneOffset)
`

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


`

default


long` `
https://developer.android.com/reference/java/time/chrono/Chronology#epochSecond(java.time.chrono.Era,%20int,%20int,%20int,%20int,%20int,%20int,%20java.time.ZoneOffset)(https://developer.android.com/reference/java/time/chrono/Era era, int yearOfEra, int month, int dayOfMonth, int hour, int minute, int second, https://developer.android.com/reference/java/time/ZoneOffset zoneOffset)
`

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


`
abstract


boolean` `
https://developer.android.com/reference/java/time/chrono/Chronology#equals(java.lang.Object)(https://developer.android.com/reference/java/lang/Object obj)
`

Checks if this chronology is equal to another chronology.


`
abstract


https://developer.android.com/reference/java/time/chrono/Era` `
https://developer.android.com/reference/java/time/chrono/Chronology#eraOf(int)(int eraValue)
`

Creates the chronology era object from the numeric value.


`
abstract


https://developer.android.com/reference/java/util/List<https://developer.android.com/reference/java/time/chrono/Era>` `
https://developer.android.com/reference/java/time/chrono/Chronology#eras()()
`

Gets the list of eras for the chronology.


`


static


https://developer.android.com/reference/java/time/chrono/Chronology` `
https://developer.android.com/reference/java/time/chrono/Chronology#from(java.time.temporal.TemporalAccessor)(https://developer.android.com/reference/java/time/temporal/TemporalAccessor temporal)
`

Obtains an instance of `Chronology` from a temporal object.


`


static


https://developer.android.com/reference/java/util/Set<https://developer.android.com/reference/java/time/chrono/Chronology>` `
https://developer.android.com/reference/java/time/chrono/Chronology#getAvailableChronologies()()
`

Returns the available chronologies.


`
abstract


https://developer.android.com/reference/java/lang/String` `
https://developer.android.com/reference/java/time/chrono/Chronology#getCalendarType()()
`

Gets the calendar type of the calendar system.


`

default


https://developer.android.com/reference/java/lang/String` `
https://developer.android.com/reference/java/time/chrono/Chronology#getDisplayName(java.time.format.TextStyle,%20java.util.Locale)(https://developer.android.com/reference/java/time/format/TextStyle style, https://developer.android.com/reference/java/util/Locale locale)
`

Gets the textual representation of this chronology.


`
abstract


https://developer.android.com/reference/java/lang/String` `
https://developer.android.com/reference/java/time/chrono/Chronology#getId()()
`

Gets the ID of the chronology.


`
abstract


int` `
https://developer.android.com/reference/java/time/chrono/Chronology#hashCode()()
`

A hash code for this chronology.


`

default


boolean` `
https://developer.android.com/reference/java/time/chrono/Chronology#isIsoBased()()
`

Checks if this chronology is ISO based.


`
abstract


boolean` `
https://developer.android.com/reference/java/time/chrono/Chronology#isLeapYear(long)(long prolepticYear)
`

Checks if the specified year is a leap year.


`

default


https://developer.android.com/reference/java/time/chrono/ChronoLocalDateTime<? extends https://developer.android.com/reference/java/time/chrono/ChronoLocalDate>` `
https://developer.android.com/reference/java/time/chrono/Chronology#localDateTime(java.time.temporal.TemporalAccessor)(https://developer.android.com/reference/java/time/temporal/TemporalAccessor temporal)
`

Obtains a local date-time in this chronology from another temporal object.


`


static


https://developer.android.com/reference/java/time/chrono/Chronology` `
https://developer.android.com/reference/java/time/chrono/Chronology#of(java.lang.String)(https://developer.android.com/reference/java/lang/String id)
`

Obtains an instance of `Chronology` from a chronology ID or
calendar system type.


`


static


https://developer.android.com/reference/java/time/chrono/Chronology` `
https://developer.android.com/reference/java/time/chrono/Chronology#ofLocale(java.util.Locale)(https://developer.android.com/reference/java/util/Locale locale)
`

Obtains an instance of `Chronology` from a locale.


`

default


https://developer.android.com/reference/java/time/chrono/ChronoPeriod` `
https://developer.android.com/reference/java/time/chrono/Chronology#period(int,%20int,%20int)(int years, int months, int days)
`

Obtains a period for this chronology based on years, months and days.


`
abstract


int` `
https://developer.android.com/reference/java/time/chrono/Chronology#prolepticYear(java.time.chrono.Era,%20int)(https://developer.android.com/reference/java/time/chrono/Era era, int yearOfEra)
`

Calculates the proleptic-year given the era and year-of-era.


`
abstract


https://developer.android.com/reference/java/time/temporal/ValueRange` `
https://developer.android.com/reference/java/time/chrono/Chronology#range(java.time.temporal.ChronoField)(https://developer.android.com/reference/java/time/temporal/ChronoField field)
`

Gets the range of valid values for the specified field.


`
abstract


https://developer.android.com/reference/java/time/chrono/ChronoLocalDate` `
https://developer.android.com/reference/java/time/chrono/Chronology#resolveDate(java.util.Map<java.time.temporal.TemporalField,java.lang.Long>,%20java.time.format.ResolverStyle)(https://developer.android.com/reference/java/util/Map<https://developer.android.com/reference/java/time/temporal/TemporalField, https://developer.android.com/reference/java/lang/Long> fieldValues, https://developer.android.com/reference/java/time/format/ResolverStyle resolverStyle)
`

Resolves parsed `ChronoField` values into a date during parsing.


`
abstract


https://developer.android.com/reference/java/lang/String` `
https://developer.android.com/reference/java/time/chrono/Chronology#toString()()
`

Outputs this chronology as a `String`.


`

default


https://developer.android.com/reference/java/time/chrono/ChronoZonedDateTime<? extends https://developer.android.com/reference/java/time/chrono/ChronoLocalDate>` `
https://developer.android.com/reference/java/time/chrono/Chronology#zonedDateTime(java.time.Instant,%20java.time.ZoneId)(https://developer.android.com/reference/java/time/Instant instant, https://developer.android.com/reference/java/time/ZoneId zone)
`

Obtains a `ChronoZonedDateTime` in this chronology from an `Instant`.


`

default


https://developer.android.com/reference/java/time/chrono/ChronoZonedDateTime<? extends https://developer.android.com/reference/java/time/chrono/ChronoLocalDate>` `
https://developer.android.com/reference/java/time/chrono/Chronology#zonedDateTime(java.time.temporal.TemporalAccessor)(https://developer.android.com/reference/java/time/temporal/TemporalAccessor temporal)
`

Obtains a `ChronoZonedDateTime` in this chronology from another temporal object.


From interface `

https://developer.android.com/reference/java/lang/Comparable

` `
abstract


int` `
https://developer.android.com/reference/java/lang/Comparable#compareTo(T)(https://developer.android.com/reference/java/time/chrono/Chronology o)
`

Compares this object with the specified object for order.


## Protected constructors

### AbstractChronology

Added in [API level 26](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels)

```
protected AbstractChronology ()
```

Creates an instance.

<br />

## Public methods

### compareTo

Added in [API level 26](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels)

```
public int compareTo (Chronology other)
```

Compares this chronology to another chronology.


The comparison order first by the chronology ID string, then by any
additional information specific to the subclass.
It is "consistent with equals", as defined by `https://developer.android.com/reference/java/lang/Comparable`.

<br />

##### Implementation Requirements:

- This implementation compares the chronology ID. Subclasses must compare any additional state that they store.

| Parameters ||
|---|---|
| `other` | `Chronology`: the other chronology to compare to, not null <br /> |

| Returns ||
|---|---|
| `int` | the comparator value, that is this ID string compared with the `other`'s ID string <br /> |

### equals

Added in [API level 26](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels)

```
public boolean equals (Object obj)
```

Checks if this chronology is equal to another chronology.


The comparison is based on the entire state of the object.

<br />

##### Implementation Requirements:

- This implementation checks the type and calls `https://developer.android.com/reference/java/time/chrono/AbstractChronology#compareTo(java.time.chrono.Chronology)`.

| Parameters ||
|---|---|
| `obj` | `Object`: the object to check, null returns false <br /> |

| Returns ||
|---|---|
| `boolean` | true if this is equal to the other chronology <br /> |

### hashCode

Added in [API level 26](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels)

```
public int hashCode ()
```

A hash code for this chronology.


The hash code should be based on the entire state of the object.

<br />

##### Implementation Requirements:

- This implementation is based on the chronology ID and class. Subclasses should add any additional state that they store.

| Returns ||
|---|---|
| `int` | a suitable hash code <br /> |

### resolveDate

Added in [API level 26](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels)

```
public ChronoLocalDate resolveDate (Map<TemporalField, Long> fieldValues, 
                ResolverStyle resolverStyle)
```

Resolves parsed `ChronoField` values into a date during parsing.


Most `TemporalField` implementations are resolved using the
resolve method on the field. By contrast, the `ChronoField` class
defines fields that only have meaning relative to the chronology.
As such, `ChronoField` date fields are resolved here in the
context of a specific chronology.


`ChronoField` instances are resolved by this method, which may
be overridden in subclasses.

- `EPOCH_DAY` - If present, this is converted to a date and all other date fields are then cross-checked against the date.
- `PROLEPTIC_MONTH` - If present, then it is split into the `YEAR` and `MONTH_OF_YEAR`. If the mode is strict or smart then the field is validated.
- `YEAR_OF_ERA` and `ERA` - If both are present, then they are combined to form a `YEAR`. In lenient mode, the `YEAR_OF_ERA` range is not validated, in smart and strict mode it is. The `ERA` is validated for range in all three modes. If only the `YEAR_OF_ERA` is present, and the mode is smart or lenient, then the last available era is assumed. In strict mode, no era is assumed and the `YEAR_OF_ERA` is left untouched. If only the `ERA` is present, then it is left untouched.
- `YEAR`, `MONTH_OF_YEAR` and `DAY_OF_MONTH` - If all three are present, then they are combined to form a date. In all three modes, the `YEAR` is validated. If the mode is smart or strict, then the month and day are validated. If the mode is lenient, then the date is combined in a manner equivalent to creating a date on the first day of the first month in the requested year, then adding the difference in months, then the difference in days. If the mode is smart, and the day-of-month is greater than the maximum for the year-month, then the day-of-month is adjusted to the last day-of-month. If the mode is strict, then the three fields must form a valid date.
- `YEAR` and `DAY_OF_YEAR` - If both are present, then they are combined to form a date. In all three modes, the `YEAR` is validated. If the mode is lenient, then the date is combined in a manner equivalent to creating a date on the first day of the requested year, then adding the difference in days. If the mode is smart or strict, then the two fields must form a valid date.
- `YEAR`, `MONTH_OF_YEAR`, `ALIGNED_WEEK_OF_MONTH` and `ALIGNED_DAY_OF_WEEK_IN_MONTH` - If all four are present, then they are combined to form a date. In all three modes, the `YEAR` is validated. If the mode is lenient, then the date is combined in a manner equivalent to creating a date on the first day of the first month in the requested year, then adding the difference in months, then the difference in weeks, then in days. If the mode is smart or strict, then the all four fields are validated to their outer ranges. The date is then combined in a manner equivalent to creating a date on the first day of the requested year and month, then adding the amount in weeks and days to reach their values. If the mode is strict, the date is additionally validated to check that the day and week adjustment did not change the month.
- `YEAR`, `MONTH_OF_YEAR`, `ALIGNED_WEEK_OF_MONTH` and `DAY_OF_WEEK` - If all four are present, then they are combined to form a date. The approach is the same as described above for years, months and weeks in `ALIGNED_DAY_OF_WEEK_IN_MONTH`. The day-of-week is adjusted as the next or same matching day-of-week once the years, months and weeks have been handled.
- `YEAR`, `ALIGNED_WEEK_OF_YEAR` and `ALIGNED_DAY_OF_WEEK_IN_YEAR` - If all three are present, then they are combined to form a date. In all three modes, the `YEAR` is validated. If the mode is lenient, then the date is combined in a manner equivalent to creating a date on the first day of the requested year, then adding the difference in weeks, then in days. If the mode is smart or strict, then the all three fields are validated to their outer ranges. The date is then combined in a manner equivalent to creating a date on the first day of the requested year, then adding the amount in weeks and days to reach their values. If the mode is strict, the date is additionally validated to check that the day and week adjustment did not change the year.
- `YEAR`, `ALIGNED_WEEK_OF_YEAR` and `DAY_OF_WEEK` - If all three are present, then they are combined to form a date. The approach is the same as described above for years and weeks in `ALIGNED_DAY_OF_WEEK_IN_YEAR`. The day-of-week is adjusted as the next or same matching day-of-week once the years and weeks have been handled.


The default implementation is suitable for most calendar systems.
If `https://developer.android.com/reference/java/time/temporal/ChronoField#YEAR_OF_ERA` is found without an `https://developer.android.com/reference/java/time/temporal/ChronoField#ERA`
then the last era in `https://developer.android.com/reference/java/time/chrono/Chronology#eras()` is used.
The implementation assumes a 7 day week, that the first day-of-month
has the value 1, that first day-of-year has the value 1, and that the
first of the month and year always exists.

<br />

| Parameters ||
|---|---|
| `fieldValues` | `Map`: the map of fields to values, which can be updated, not null <br /> |
| `resolverStyle` | `ResolverStyle`: the requested type of resolve, not null <br /> |

| Returns ||
|---|---|
| `https://developer.android.com/reference/java/time/chrono/ChronoLocalDate` | the resolved date, null if insufficient information to create a date <br /> |

| Throws ||
|---|---|
| `https://developer.android.com/reference/java/time/DateTimeException` | if the date cannot be resolved, typically because of a conflict in the input data |

### toString

Added in [API level 26](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels)

```
public String toString ()
```

Outputs this chronology as a `String`, using the chronology ID.

<br />

| Returns ||
|---|---|
| `https://developer.android.com/reference/java/lang/String` | a string representation of this chronology, not null <br /> |