Added in [API level 26](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels) Summary: [Fields](https://developer.android.com/reference/java/time/chrono/IsoChronology#lfields) \| [Methods](https://developer.android.com/reference/java/time/chrono/IsoChronology#pubmethods) \| [Inherited Methods](https://developer.android.com/reference/java/time/chrono/IsoChronology#inhmethods)
# IsoChronology
`
public
final
class
IsoChronology
`
`
`
`
extends https://developer.android.com/reference/java/time/chrono/AbstractChronology
`
`
implements
https://developer.android.com/reference/java/io/Serializable
`
|---|---|---|
| [java.lang.Object](https://developer.android.com/reference/java/lang/Object) |||
| ↳ | [java.time.chrono.AbstractChronology](https://developer.android.com/reference/java/time/chrono/AbstractChronology) ||
| | ↳ | java.time.chrono.IsoChronology |
*** ** * ** ***
The ISO calendar system.
This chronology defines the rules of the ISO calendar system.
This calendar system is based on the ISO-8601 standard, which is the
*de facto* world calendar.
The fields are defined as follows:
- era - There are two eras, 'Current Era' (CE) and 'Before Current Era' (BCE).
- year-of-era - The year-of-era is the same as the proleptic-year for the current CE era. For the BCE era before the ISO epoch the year increases from 1 upwards as time goes backwards.
- proleptic-year - The proleptic year is the same as the year-of-era for the current era. For the previous era, years have zero, then negative values.
- month-of-year - There are 12 months in an ISO year, numbered from 1 to 12.
- day-of-month - There are between 28 and 31 days in each of the ISO month, numbered from 1 to 31. Months 4, 6, 9 and 11 have 30 days, Months 1, 3, 5, 7, 8, 10 and 12 have 31 days. Month 2 has 28 days, or 29 in a leap year.
- day-of-year - There are 365 days in a standard ISO year and 366 in a leap year. The days are numbered from 1 to 365 or 1 to 366.
- leap-year - Leap years occur every 4 years, except where the year is divisble by 100 and not divisble by 400.
## Summary
| ### Fields ||
|---|---|
| ` public static final https://developer.android.com/reference/java/time/chrono/IsoChronology` | `https://developer.android.com/reference/java/time/chrono/IsoChronology#INSTANCE` Singleton instance of the ISO chronology. |
| ### Public methods ||
|---|---|
| ` https://developer.android.com/reference/java/time/LocalDate` | ` https://developer.android.com/reference/java/time/chrono/IsoChronology#date(int,%20int,%20int)(int prolepticYear, int month, int dayOfMonth) ` Obtains an ISO local date from the proleptic-year, month-of-year and day-of-month fields. |
| ` https://developer.android.com/reference/java/time/LocalDate` | ` https://developer.android.com/reference/java/time/chrono/IsoChronology#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 an ISO local date from the era, year-of-era, month-of-year and day-of-month fields. |
| ` https://developer.android.com/reference/java/time/LocalDate` | ` https://developer.android.com/reference/java/time/chrono/IsoChronology#date(java.time.temporal.TemporalAccessor)(https://developer.android.com/reference/java/time/temporal/TemporalAccessor temporal) ` Obtains an ISO local date from another date-time object. |
| ` https://developer.android.com/reference/java/time/LocalDate` | ` https://developer.android.com/reference/java/time/chrono/IsoChronology#dateEpochDay(long)(long epochDay) ` Obtains an ISO local date from the epoch-day. |
| ` https://developer.android.com/reference/java/time/LocalDate` | ` https://developer.android.com/reference/java/time/chrono/IsoChronology#dateNow(java.time.ZoneId)(https://developer.android.com/reference/java/time/ZoneId zone) ` Obtains the current ISO local date from the system clock in the specified time-zone. |
| ` https://developer.android.com/reference/java/time/LocalDate` | ` https://developer.android.com/reference/java/time/chrono/IsoChronology#dateNow()() ` Obtains the current ISO local date from the system clock in the default time-zone. |
| ` https://developer.android.com/reference/java/time/LocalDate` | ` https://developer.android.com/reference/java/time/chrono/IsoChronology#dateNow(java.time.Clock)(https://developer.android.com/reference/java/time/Clock clock) ` Obtains the current ISO local date from the specified clock. |
| ` https://developer.android.com/reference/java/time/LocalDate` | ` https://developer.android.com/reference/java/time/chrono/IsoChronology#dateYearDay(java.time.chrono.Era,%20int,%20int)(https://developer.android.com/reference/java/time/chrono/Era era, int yearOfEra, int dayOfYear) ` Obtains an ISO local date from the era, year-of-era and day-of-year fields. |
| ` https://developer.android.com/reference/java/time/LocalDate` | ` https://developer.android.com/reference/java/time/chrono/IsoChronology#dateYearDay(int,%20int)(int prolepticYear, int dayOfYear) ` Obtains an ISO local date from the proleptic-year and day-of-year fields. |
| ` long` | ` https://developer.android.com/reference/java/time/chrono/IsoChronology#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. |
| ` https://developer.android.com/reference/java/time/chrono/IsoEra` | ` https://developer.android.com/reference/java/time/chrono/IsoChronology#eraOf(int)(int eraValue) ` |
| ` https://developer.android.com/reference/java/util/List` | ` https://developer.android.com/reference/java/time/chrono/IsoChronology#eras()() ` |
| ` https://developer.android.com/reference/java/lang/String` | ` https://developer.android.com/reference/java/time/chrono/IsoChronology#getCalendarType()() ` Gets the calendar type of the underlying calendar system - 'iso8601'. |
| ` https://developer.android.com/reference/java/lang/String` | ` https://developer.android.com/reference/java/time/chrono/IsoChronology#getId()() ` Gets the ID of the chronology - 'ISO'. |
| ` boolean` | ` https://developer.android.com/reference/java/time/chrono/IsoChronology#isIsoBased()() ` `IsoChronology` is an ISO based chronology, which supports fields in `https://developer.android.com/reference/java/time/temporal/IsoFields`, such as `https://developer.android.com/reference/java/time/temporal/IsoFields#DAY_OF_QUARTER` and `https://developer.android.com/reference/java/time/temporal/IsoFields#QUARTER_OF_YEAR`. |
| ` boolean` | ` https://developer.android.com/reference/java/time/chrono/IsoChronology#isLeapYear(long)(long prolepticYear) ` Checks if the year is a leap year, according to the ISO proleptic calendar system rules. |
| ` https://developer.android.com/reference/java/time/LocalDateTime` | ` https://developer.android.com/reference/java/time/chrono/IsoChronology#localDateTime(java.time.temporal.TemporalAccessor)(https://developer.android.com/reference/java/time/temporal/TemporalAccessor temporal) ` Obtains an ISO local date-time from another date-time object. |
| ` https://developer.android.com/reference/java/time/Period` | ` https://developer.android.com/reference/java/time/chrono/IsoChronology#period(int,%20int,%20int)(int years, int months, int days) ` Obtains a period for this chronology based on years, months and days. |
| ` int` | ` https://developer.android.com/reference/java/time/chrono/IsoChronology#prolepticYear(java.time.chrono.Era,%20int)(https://developer.android.com/reference/java/time/chrono/Era era, int yearOfEra) ` |
| ` https://developer.android.com/reference/java/time/temporal/ValueRange` | ` https://developer.android.com/reference/java/time/chrono/IsoChronology#range(java.time.temporal.ChronoField)(https://developer.android.com/reference/java/time/temporal/ChronoField field) ` |
| ` https://developer.android.com/reference/java/time/LocalDate` | ` https://developer.android.com/reference/java/time/chrono/IsoChronology#resolveDate(java.util.Map,%20java.time.format.ResolverStyle)(https://developer.android.com/reference/java/util/Map 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/time/ZonedDateTime` | ` https://developer.android.com/reference/java/time/chrono/IsoChronology#zonedDateTime(java.time.temporal.TemporalAccessor)(https://developer.android.com/reference/java/time/temporal/TemporalAccessor temporal) ` Obtains an ISO zoned date-time from another date-time object. |
| ` https://developer.android.com/reference/java/time/ZonedDateTime` | ` https://developer.android.com/reference/java/time/chrono/IsoChronology#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 an ISO zoned date-time in this chronology from an `Instant`. |
### Inherited methods
From class `
https://developer.android.com/reference/java/time/chrono/AbstractChronology
` `
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,%20java.time.format.ResolverStyle)(https://developer.android.com/reference/java/util/Map 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.
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/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#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` `
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,%20java.time.format.ResolverStyle)(https://developer.android.com/reference/java/util/Map 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` `
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` `
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.
## Fields
### INSTANCE
Added in [API level 26](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels)
```
public static final IsoChronology INSTANCE
```
Singleton instance of the ISO chronology.
## Public methods
### date
Added in [API level 26](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels)
```
public LocalDate date (int prolepticYear,
int month,
int dayOfMonth)
```
Obtains an ISO local date from the proleptic-year, month-of-year
and day-of-month fields.
This is equivalent to `https://developer.android.com/reference/java/time/LocalDate#of(int,%20int,%20int)`.
| Parameters ||
|---|---|
| `prolepticYear` | `int`: the ISO proleptic-year
|
| `month` | `int`: the ISO month-of-year
|
| `dayOfMonth` | `int`: the ISO day-of-month
|
| Returns ||
|---|---|
| `https://developer.android.com/reference/java/time/LocalDate` | the ISO local date, not null
|
| Throws ||
|---|---|
| `https://developer.android.com/reference/java/time/DateTimeException` | if unable to create the date |
### date
Added in [API level 26](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels)
```
public LocalDate date (Era era,
int yearOfEra,
int month,
int dayOfMonth)
```
Obtains an ISO local date from the era, year-of-era, month-of-year
and day-of-month fields.
| Parameters ||
|---|---|
| `era` | `Era`: the ISO era, not null
|
| `yearOfEra` | `int`: the ISO year-of-era
|
| `month` | `int`: the ISO month-of-year
|
| `dayOfMonth` | `int`: the ISO day-of-month
|
| Returns ||
|---|---|
| `https://developer.android.com/reference/java/time/LocalDate` | the ISO local date, not null
|
| Throws ||
|---|---|
| `https://developer.android.com/reference/java/lang/ClassCastException` | if the type of `era` is not `IsoEra` |
| `https://developer.android.com/reference/java/time/DateTimeException` | if unable to create the date |
### date
Added in [API level 26](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels)
```
public LocalDate date (TemporalAccessor temporal)
```
Obtains an ISO local date from another date-time object.
This is equivalent to `https://developer.android.com/reference/java/time/LocalDate#from(java.time.temporal.TemporalAccessor)`.
| Parameters ||
|---|---|
| `temporal` | `TemporalAccessor`: the date-time object to convert, not null
|
| Returns ||
|---|---|
| `https://developer.android.com/reference/java/time/LocalDate` | the ISO local date, not null
|
| Throws ||
|---|---|
| `https://developer.android.com/reference/java/time/DateTimeException` | if unable to create the date |
### dateEpochDay
Added in [API level 26](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels)
```
public LocalDate dateEpochDay (long epochDay)
```
Obtains an ISO local date from the epoch-day.
This is equivalent to `https://developer.android.com/reference/java/time/LocalDate#ofEpochDay(long)`.
| Parameters ||
|---|---|
| `epochDay` | `long`: the epoch day
|
| Returns ||
|---|---|
| `https://developer.android.com/reference/java/time/LocalDate` | the ISO local date, not null
|
| Throws ||
|---|---|
| `https://developer.android.com/reference/java/time/DateTimeException` | if unable to create the date |
### dateNow
Added in [API level 26](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels)
```
public LocalDate dateNow (ZoneId zone)
```
Obtains the current ISO local date from the system clock in the specified time-zone.
This will query the `https://developer.android.com/reference/java/time/Clock#system(java.time.ZoneId)` to obtain the current date.
Specifying the time-zone avoids dependence on the default time-zone.
Using this method will prevent the ability to use an alternate clock for testing
because the clock is hard-coded.
| Parameters ||
|---|---|
| `zone` | `ZoneId`
|
| Returns ||
|---|---|
| `https://developer.android.com/reference/java/time/LocalDate` | the current ISO local date using the system clock, not null
|
| Throws ||
|---|---|
| `https://developer.android.com/reference/java/time/DateTimeException` | if unable to create the date |
### dateNow
Added in [API level 26](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels)
```
public LocalDate dateNow ()
```
Obtains the current ISO local date from the system clock in the default time-zone.
This will query the `https://developer.android.com/reference/java/time/Clock#systemDefaultZone()` in the default
time-zone to obtain the current date.
Using this method will prevent the ability to use an alternate clock for testing
because the clock is hard-coded.
| Returns ||
|---|---|
| `https://developer.android.com/reference/java/time/LocalDate` | the current ISO local date using the system clock and default time-zone, not null
|
| Throws ||
|---|---|
| `https://developer.android.com/reference/java/time/DateTimeException` | if unable to create the date |
### dateNow
Added in [API level 26](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels)
```
public LocalDate dateNow (Clock clock)
```
Obtains the current ISO local date from the specified clock.
This will query the specified clock to obtain the current date - today.
Using this method allows the use of an alternate clock for testing.
The alternate clock may be introduced using `https://developer.android.com/reference/java/time/Clock`.
| Parameters ||
|---|---|
| `clock` | `Clock`: the clock to use, not null
|
| Returns ||
|---|---|
| `https://developer.android.com/reference/java/time/LocalDate` | the current ISO local date, not null
|
| Throws ||
|---|---|
| `https://developer.android.com/reference/java/time/DateTimeException` | if unable to create the date |
### dateYearDay
Added in [API level 26](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels)
```
public LocalDate dateYearDay (Era era,
int yearOfEra,
int dayOfYear)
```
Obtains an ISO local date from the era, year-of-era and day-of-year fields.
| Parameters ||
|---|---|
| `era` | `Era`: the ISO era, not null
|
| `yearOfEra` | `int`: the ISO year-of-era
|
| `dayOfYear` | `int`: the ISO day-of-year
|
| Returns ||
|---|---|
| `https://developer.android.com/reference/java/time/LocalDate` | the ISO local date, not null
|
| Throws ||
|---|---|
| `https://developer.android.com/reference/java/time/DateTimeException` | if unable to create the date |
### dateYearDay
Added in [API level 26](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels)
```
public LocalDate dateYearDay (int prolepticYear,
int dayOfYear)
```
Obtains an ISO local date from the proleptic-year and day-of-year fields.
This is equivalent to `https://developer.android.com/reference/java/time/LocalDate#ofYearDay(int,%20int)`.
| Parameters ||
|---|---|
| `prolepticYear` | `int`: the ISO proleptic-year
|
| `dayOfYear` | `int`: the ISO day-of-year
|
| Returns ||
|---|---|
| `https://developer.android.com/reference/java/time/LocalDate` | the ISO local date, not null
|
| Throws ||
|---|---|
| `https://developer.android.com/reference/java/time/DateTimeException` | if unable to create the date |
### epochSecond
Added in [API level 34](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels)
```
public long epochSecond (int prolepticYear,
int month,
int dayOfMonth,
int hour,
int minute,
int second,
ZoneOffset zoneOffset)
```
Gets the number of seconds from the epoch of 1970-01-01T00:00:00Z.
The number of seconds is calculated using the year,
month, day-of-month, hour, minute, second, and zoneOffset.
| Parameters ||
|---|---|
| `prolepticYear` | `int`: the year, from MIN_YEAR to MAX_YEAR
|
| `month` | `int`: the month-of-year, from 1 to 12
|
| `dayOfMonth` | `int`: the day-of-month, from 1 to 31
|
| `hour` | `int`: the hour-of-day, from 0 to 23
|
| `minute` | `int`: the minute-of-hour, from 0 to 59
|
| `second` | `int`: the second-of-minute, from 0 to 59
|
| `zoneOffset` | `ZoneOffset`: the zone offset, not null
|
| Returns ||
|---|---|
| `long` | the number of seconds relative to 1970-01-01T00:00:00Z, may be negative
|
| Throws ||
|---|---|
| `https://developer.android.com/reference/java/time/DateTimeException` | if the value of any argument is out of range, or if the day-of-month is invalid for the month-of-year |
### eraOf
Added in [API level 26](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels)
```
public IsoEra eraOf (int eraValue)
```
| Parameters ||
|---|---|
| `eraValue` | `int`
|
| Returns ||
|---|---|
| `https://developer.android.com/reference/java/time/chrono/IsoEra` |
|
### eras
Added in [API level 26](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels)
```
public List eras ()
```
| Returns ||
|---|---|
| `https://developer.android.com/reference/java/util/List` |
|
### getCalendarType
Added in [API level 26](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels)
```
public String getCalendarType ()
```
Gets the calendar type of the underlying calendar system - 'iso8601'.
The calendar type is an identifier defined by the
*Unicode Locale Data Markup Language (LDML)* specification.
It can be used to lookup the `Chronology` using `https://developer.android.com/reference/java/time/chrono/Chronology#of(java.lang.String)`.
It can also be used as part of a locale, accessible via
`https://developer.android.com/reference/java/util/Locale#getUnicodeLocaleType(java.lang.String)` with the key 'ca'.
| Returns ||
|---|---|
| `https://developer.android.com/reference/java/lang/String` | the calendar system type - 'iso8601'
|
**See also:**
- `https://developer.android.com/reference/java/time/chrono/IsoChronology#getId()`
### getId
Added in [API level 26](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels)
```
public String getId ()
```
Gets the ID of the chronology - 'ISO'.
The ID uniquely identifies the `Chronology`.
It can be used to lookup the `Chronology` using `https://developer.android.com/reference/java/time/chrono/Chronology#of(java.lang.String)`.
| Returns ||
|---|---|
| `https://developer.android.com/reference/java/lang/String` | the chronology ID - 'ISO'
|
**See also:**
- `https://developer.android.com/reference/java/time/chrono/IsoChronology#getCalendarType()`
### isIsoBased
Added in [version 37.2](https://developer.android.com/topic/libraries/support-library/revisions)
```
public boolean isIsoBased ()
```
`IsoChronology` is an ISO based chronology, which supports fields
in `https://developer.android.com/reference/java/time/temporal/IsoFields`, such as `https://developer.android.com/reference/java/time/temporal/IsoFields#DAY_OF_QUARTER`
and `https://developer.android.com/reference/java/time/temporal/IsoFields#QUARTER_OF_YEAR`.
| Returns ||
|---|---|
| `boolean` | `true`
|
**See also:**
- `https://developer.android.com/reference/java/time/temporal/IsoFields`
### isLeapYear
Added in [API level 26](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels)
```
public boolean isLeapYear (long prolepticYear)
```
Checks if the year is a leap year, according to the ISO proleptic
calendar system rules.
This method applies the current rules for leap years across the whole time-line.
In general, a year is a leap year if it is divisible by four without
remainder. However, years divisible by 100, are not leap years, with
the exception of years divisible by 400 which are.
For example, 1904 is a leap year it is divisible by 4.
1900 was not a leap year as it is divisible by 100, however 2000 was a
leap year as it is divisible by 400.
The calculation is proleptic - applying the same rules into the far future and far past.
This is historically inaccurate, but is correct for the ISO-8601 standard.
| Parameters ||
|---|---|
| `prolepticYear` | `long`: the ISO proleptic year to check
|
| Returns ||
|---|---|
| `boolean` | true if the year is leap, false otherwise
|
### localDateTime
Added in [API level 26](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels)
```
public LocalDateTime localDateTime (TemporalAccessor temporal)
```
Obtains an ISO local date-time from another date-time object.
This is equivalent to `https://developer.android.com/reference/java/time/LocalDateTime#from(java.time.temporal.TemporalAccessor)`.
| Parameters ||
|---|---|
| `temporal` | `TemporalAccessor`: the date-time object to convert, not null
|
| Returns ||
|---|---|
| `https://developer.android.com/reference/java/time/LocalDateTime` | the ISO local date-time, not null
|
| Throws ||
|---|---|
| `https://developer.android.com/reference/java/time/DateTimeException` | if unable to create the date-time |
### period
Added in [API level 26](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels)
```
public Period period (int years,
int months,
int days)
```
Obtains a period for this chronology based on years, months and days.
This returns a period tied to the ISO chronology using the specified
years, months and days. See `https://developer.android.com/reference/java/time/Period` for further details.
| Parameters ||
|---|---|
| `years` | `int`: the number of years, may be negative
|
| `months` | `int`: the number of years, may be negative
|
| `days` | `int`: the number of years, may be negative
|
| Returns ||
|---|---|
| `https://developer.android.com/reference/java/time/Period` | the ISO period, not null
|
### prolepticYear
Added in [API level 26](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels)
```
public int prolepticYear (Era era,
int yearOfEra)
```
| Parameters ||
|---|---|
| `era` | `Era`
|
| `yearOfEra` | `int`
|
| Returns ||
|---|---|
| `int` |
|
### range
Added in [API level 26](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels)
```
public ValueRange range (ChronoField field)
```
| Parameters ||
|---|---|
| `field` | `ChronoField`
|
| Returns ||
|---|---|
| `https://developer.android.com/reference/java/time/temporal/ValueRange` |
|
### resolveDate
Added in [API level 26](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels)
```
public LocalDate resolveDate (Map 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 on the ISO calendar system are resolved
as follows.
- `EPOCH_DAY` - If present, this is converted to a `LocalDate` 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 current era (CE/AD) 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 `LocalDate`. In all three modes, the `YEAR` is validated. If the mode is smart or strict, then the month and day are validated, with the day validated from 1 to 31. If the mode is lenient, then the date is combined in a manner equivalent to creating a date on the first of January 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 `LocalDate`. 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 of January in 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 `LocalDate`. 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 of January 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 `LocalDate`. 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 `LocalDate`. 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 of January in 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 `LocalDate`. 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.
| Parameters ||
|---|---|
| `fieldValues` | `Map`: the map of fields to values, which can be updated, not null
|
| `resolverStyle` | `ResolverStyle`: the requested type of resolve, not null
|
| Returns ||
|---|---|
| `https://developer.android.com/reference/java/time/LocalDate` | the resolved date, null if insufficient information to create a date
|
| Throws ||
|---|---|
| `https://developer.android.com/reference/java/time/DateTimeException` | if the date cannot be resolved, typically because of a conflict in the input data |
### zonedDateTime
Added in [API level 26](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels)
```
public ZonedDateTime zonedDateTime (TemporalAccessor temporal)
```
Obtains an ISO zoned date-time from another date-time object.
This is equivalent to `https://developer.android.com/reference/java/time/ZonedDateTime#from(java.time.temporal.TemporalAccessor)`.
| Parameters ||
|---|---|
| `temporal` | `TemporalAccessor`: the date-time object to convert, not null
|
| Returns ||
|---|---|
| `https://developer.android.com/reference/java/time/ZonedDateTime` | the ISO zoned date-time, not null
|
| Throws ||
|---|---|
| `https://developer.android.com/reference/java/time/DateTimeException` | if unable to create the date-time |
### zonedDateTime
Added in [API level 26](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels)
```
public ZonedDateTime zonedDateTime (Instant instant,
ZoneId zone)
```
Obtains an ISO zoned date-time in this chronology from an `Instant`.
This is equivalent to `https://developer.android.com/reference/java/time/ZonedDateTime#ofInstant(java.time.Instant,%20java.time.ZoneId)`.
| Parameters ||
|---|---|
| `instant` | `Instant`: the instant to create the date-time from, not null
|
| `zone` | `ZoneId`: the time-zone, not null
|
| Returns ||
|---|---|
| `https://developer.android.com/reference/java/time/ZonedDateTime` | the zoned date-time, not null
|
| Throws ||
|---|---|
| `https://developer.android.com/reference/java/time/DateTimeException` | if the result exceeds the supported range |