- java.lang.Object
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- java.time.chrono.AbstractChronology
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- java.time.chrono.IsoChronology
 
 
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- All Implemented Interfaces:
- Serializable,- Comparable<Chronology>,- Chronology
 
 public final class IsoChronology extends AbstractChronology implements Serializable 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.
 - Implementation Requirements:
- This class is immutable and thread-safe.
- Since:
- 1.8
- See Also:
- Serialized Form
 
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Field SummaryFields Modifier and Type Field Description static IsoChronologyINSTANCESingleton instance of the ISO chronology.
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Method SummaryAll Methods Instance Methods Concrete Methods Modifier and Type Method Description LocalDatedate(int prolepticYear, int month, int dayOfMonth)Obtains an ISO local date from the proleptic-year, month-of-year and day-of-month fields.LocalDatedate(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.LocalDatedate(TemporalAccessor temporal)Obtains an ISO local date from another date-time object.LocalDatedateEpochDay(long epochDay)Obtains an ISO local date from the epoch-day.LocalDatedateNow()Obtains the current ISO local date from the system clock in the default time-zone.LocalDatedateNow(Clock clock)Obtains the current ISO local date from the specified clock.LocalDatedateNow(ZoneId zone)Obtains the current ISO local date from the system clock in the specified time-zone.LocalDatedateYearDay(int prolepticYear, int dayOfYear)Obtains an ISO local date from the proleptic-year and day-of-year fields.LocalDatedateYearDay(Era era, int yearOfEra, int dayOfYear)Obtains an ISO local date from the era, year-of-era and day-of-year fields.longepochSecond(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.StringgetCalendarType()Gets the calendar type of the underlying calendar system - 'iso8601'.StringgetId()Gets the ID of the chronology - 'ISO'.booleanisLeapYear(long prolepticYear)Checks if the year is a leap year, according to the ISO proleptic calendar system rules.LocalDateTimelocalDateTime(TemporalAccessor temporal)Obtains an ISO local date-time from another date-time object.Periodperiod(int years, int months, int days)Obtains a period for this chronology based on years, months and days.LocalDateresolveDate(Map<TemporalField,Long> fieldValues, ResolverStyle resolverStyle)Resolves parsedChronoFieldvalues into a date during parsing.ZonedDateTimezonedDateTime(Instant instant, ZoneId zone)Obtains an ISO zoned date-time in this chronology from anInstant.ZonedDateTimezonedDateTime(TemporalAccessor temporal)Obtains an ISO zoned date-time from another date-time object.- 
Methods declared in class java.time.chrono.AbstractChronologycompareTo, equals, hashCode, toString
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Methods declared in class java.lang.Objectclone, finalize, getClass, notify, notifyAll, wait, wait, wait
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Methods declared in interface java.time.chrono.ChronologyepochSecond, eraOf, eras, getDisplayName, prolepticYear, range
 
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Field Detail- 
INSTANCEpublic static final IsoChronology INSTANCE Singleton instance of the ISO chronology.
 
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Method Detail- 
getIdpublic String getId() Gets the ID of the chronology - 'ISO'.The ID uniquely identifies the Chronology. It can be used to lookup theChronologyusingChronology.of(String).- Specified by:
- getIdin interface- Chronology
- Returns:
- the chronology ID - 'ISO'
- See Also:
- getCalendarType()
 
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getCalendarTypepublic 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 ChronologyusingChronology.of(String). It can also be used as part of a locale, accessible viaLocale.getUnicodeLocaleType(String)with the key 'ca'.- Specified by:
- getCalendarTypein interface- Chronology
- Returns:
- the calendar system type - 'iso8601'
- See Also:
- getId()
 
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datepublic 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.- Specified by:
- datein interface- Chronology
- Parameters:
- era- the ISO era, not null
- yearOfEra- the ISO year-of-era
- month- the ISO month-of-year
- dayOfMonth- the ISO day-of-month
- Returns:
- the ISO local date, not null
- Throws:
- DateTimeException- if unable to create the date
- ClassCastException- if the type of- erais not- IsoEra
 
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datepublic 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 LocalDate.of(int, int, int).- Specified by:
- datein interface- Chronology
- Parameters:
- prolepticYear- the ISO proleptic-year
- month- the ISO month-of-year
- dayOfMonth- the ISO day-of-month
- Returns:
- the ISO local date, not null
- Throws:
- DateTimeException- if unable to create the date
 
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dateYearDaypublic LocalDate dateYearDay(Era era, int yearOfEra, int dayOfYear) Obtains an ISO local date from the era, year-of-era and day-of-year fields.- Specified by:
- dateYearDayin interface- Chronology
- Parameters:
- era- the ISO era, not null
- yearOfEra- the ISO year-of-era
- dayOfYear- the ISO day-of-year
- Returns:
- the ISO local date, not null
- Throws:
- DateTimeException- if unable to create the date
 
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dateYearDaypublic LocalDate dateYearDay(int prolepticYear, int dayOfYear) Obtains an ISO local date from the proleptic-year and day-of-year fields.This is equivalent to LocalDate.ofYearDay(int, int).- Specified by:
- dateYearDayin interface- Chronology
- Parameters:
- prolepticYear- the ISO proleptic-year
- dayOfYear- the ISO day-of-year
- Returns:
- the ISO local date, not null
- Throws:
- DateTimeException- if unable to create the date
 
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dateEpochDaypublic LocalDate dateEpochDay(long epochDay) Obtains an ISO local date from the epoch-day.This is equivalent to LocalDate.ofEpochDay(long).- Specified by:
- dateEpochDayin interface- Chronology
- Parameters:
- epochDay- the epoch day
- Returns:
- the ISO local date, not null
- Throws:
- DateTimeException- if unable to create the date
 
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datepublic LocalDate date(TemporalAccessor temporal) Obtains an ISO local date from another date-time object.This is equivalent to LocalDate.from(TemporalAccessor).- Specified by:
- datein interface- Chronology
- Parameters:
- temporal- the date-time object to convert, not null
- Returns:
- the ISO local date, not null
- Throws:
- DateTimeException- if unable to create the date
- See Also:
- ChronoLocalDate.from(TemporalAccessor)
 
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epochSecondpublic 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. - Specified by:
- epochSecondin interface- Chronology
- Parameters:
- prolepticYear- the year, from MIN_YEAR to MAX_YEAR
- month- the month-of-year, from 1 to 12
- dayOfMonth- the day-of-month, from 1 to 31
- hour- the hour-of-day, from 0 to 23
- minute- the minute-of-hour, from 0 to 59
- second- the second-of-minute, from 0 to 59
- zoneOffset- the zone offset, not null
- Returns:
- the number of seconds relative to 1970-01-01T00:00:00Z, may be negative
- Throws:
- DateTimeException- if the value of any argument is out of range, or if the day-of-month is invalid for the month-of-year
- Since:
- 9
 
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localDateTimepublic LocalDateTime localDateTime(TemporalAccessor temporal) Obtains an ISO local date-time from another date-time object.This is equivalent to LocalDateTime.from(TemporalAccessor).- Specified by:
- localDateTimein interface- Chronology
- Parameters:
- temporal- the date-time object to convert, not null
- Returns:
- the ISO local date-time, not null
- Throws:
- DateTimeException- if unable to create the date-time
- See Also:
- ChronoLocalDateTime.from(TemporalAccessor)
 
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zonedDateTimepublic ZonedDateTime zonedDateTime(TemporalAccessor temporal) Obtains an ISO zoned date-time from another date-time object.This is equivalent to ZonedDateTime.from(TemporalAccessor).- Specified by:
- zonedDateTimein interface- Chronology
- Parameters:
- temporal- the date-time object to convert, not null
- Returns:
- the ISO zoned date-time, not null
- Throws:
- DateTimeException- if unable to create the date-time
- See Also:
- ChronoZonedDateTime.from(TemporalAccessor)
 
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zonedDateTimepublic ZonedDateTime zonedDateTime(Instant instant, ZoneId zone) Obtains an ISO zoned date-time in this chronology from anInstant.This is equivalent to ZonedDateTime.ofInstant(Instant, ZoneId).- Specified by:
- zonedDateTimein interface- Chronology
- Parameters:
- instant- the instant to create the date-time from, not null
- zone- the time-zone, not null
- Returns:
- the zoned date-time, not null
- Throws:
- DateTimeException- if the result exceeds the supported range
 
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dateNowpublic LocalDate dateNow() Obtains the current ISO local date from the system clock in the default time-zone.This will query the system clockin 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. - Specified by:
- dateNowin interface- Chronology
- Returns:
- the current ISO local date using the system clock and default time-zone, not null
- Throws:
- DateTimeException- if unable to create the date
 
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dateNowpublic LocalDate dateNow(ZoneId zone) Obtains the current ISO local date from the system clock in the specified time-zone.This will query the system clockto 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. - Specified by:
- dateNowin interface- Chronology
- Parameters:
- zone- the zone ID to use, not null
- Returns:
- the current ISO local date using the system clock, not null
- Throws:
- DateTimeException- if unable to create the date
 
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dateNowpublic 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 dependency injection.- Specified by:
- dateNowin interface- Chronology
- Parameters:
- clock- the clock to use, not null
- Returns:
- the current ISO local date, not null
- Throws:
- DateTimeException- if unable to create the date
 
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isLeapYearpublic 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. - Specified by:
- isLeapYearin interface- Chronology
- Parameters:
- prolepticYear- the ISO proleptic year to check
- Returns:
- true if the year is leap, false otherwise
 
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resolveDatepublic LocalDate resolveDate(Map<TemporalField,Long> fieldValues, ResolverStyle resolverStyle) Resolves parsedChronoFieldvalues into a date during parsing.Most TemporalFieldimplementations are resolved using the resolve method on the field. By contrast, theChronoFieldclass defines fields that only have meaning relative to the chronology. As such,ChronoFielddate fields are resolved here in the context of a specific chronology.ChronoFieldinstances on the ISO calendar system are resolved as follows.- EPOCH_DAY- If present, this is converted to a- LocalDateand all other date fields are then cross-checked against the date.
- PROLEPTIC_MONTH- If present, then it is split into the- YEARand- MONTH_OF_YEAR. If the mode is strict or smart then the field is validated.
- YEAR_OF_ERAand- ERA- If both are present, then they are combined to form a- YEAR. In lenient mode, the- YEAR_OF_ERArange is not validated, in smart and strict mode it is. The- ERAis validated for range in all three modes. If only the- YEAR_OF_ERAis 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_ERAis left untouched. If only the- ERAis present, then it is left untouched.
- YEAR,- MONTH_OF_YEARand- DAY_OF_MONTH- If all three are present, then they are combined to form a- LocalDate. In all three modes, the- YEARis 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.
- YEARand- DAY_OF_YEAR- If both are present, then they are combined to form a- LocalDate. In all three modes, the- YEARis 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_MONTHand- ALIGNED_DAY_OF_WEEK_IN_MONTH- If all four are present, then they are combined to form a- LocalDate. In all three modes, the- YEARis 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_MONTHand- 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_YEARand- ALIGNED_DAY_OF_WEEK_IN_YEAR- If all three are present, then they are combined to form a- LocalDate. In all three modes, the- YEARis 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_YEARand- 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.
 - Specified by:
- resolveDatein interface- Chronology
- Overrides:
- resolveDatein class- AbstractChronology
- Parameters:
- fieldValues- the map of fields to values, which can be updated, not null
- resolverStyle- the requested type of resolve, not null
- Returns:
- the resolved date, null if insufficient information to create a date
- Throws:
- DateTimeException- if the date cannot be resolved, typically because of a conflict in the input data
 
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periodpublic 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 Periodfor further details.- Specified by:
- periodin interface- Chronology
- Parameters:
- years- the number of years, may be negative
- months- the number of years, may be negative
- days- the number of years, may be negative
- Returns:
- the period in terms of this chronology, not null
 
 
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