Package org.threeten.extra.chrono

Class HybridChronology

java.lang.Object
java.time.chrono.AbstractChronology
org.threeten.extra.chrono.HybridChronology
All Implemented Interfaces:
Serializable, Comparable<Chronology>, Chronology
public final class HybridChronology extends AbstractChronology implements Serializable
The Julian-Gregorian hybrid calendar system.

The British calendar system follows the rules of the Julian calendar until 1752 and the rules of the Gregorian (ISO) calendar since then. The Julian differs from the Gregorian only in terms of the leap year rule.

The Julian and Gregorian calendar systems are linked to Rome and the Vatican with the Julian preceding the Gregorian. The Gregorian was introduced to handle the drift of the seasons through the year due to the inaccurate Julian leap year rules. When first introduced by the Vatican in 1582, the cutover resulted in a "gap" of 10 days.

While the calendar was introduced in 1582, it was not adopted everywhere. Britain did not adopt it until the 1752, when Wednesday 2nd September 1752 was followed by Thursday 14th September 1752.

This chronology implements the proleptic Julian calendar system followed by the proleptic Gregorian calendar system (identical to the ISO calendar system). Dates are aligned such that 0001-01-01 (British) is 0000-12-30 (ISO).

This class implements a calendar where January 1st is the start of the year. The history of the start of the year is complex and using the current standard is the most consistent.

The eras of this calendar system are defined by JulianEra to avoid unnecessary duplication.

The fields are defined as follows:

  • era - There are two eras, the current 'Anno Domini' (AD) and the previous era 'Before Christ' (BC).
  • year-of-era - The year-of-era for the current era increases uniformly from the epoch at year one. For the previous era the year increases from one 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 a year, numbered from 1 to 12.
  • day-of-month - There are between 28 and 31 days in each 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. The cutover month, September 1752, has a value range from 1 to 30, but a length of 19.
  • day-of-year - There are 365 days in a standard year and 366 in a leap year. The days are numbered from 1 to 365 or 1 to 366. The cutover year 1752 has values from 1 to 355 and a length of 355 days.

Implementation Requirements

This class is immutable and thread-safe.
See Also:

  • Field Details

    • INSTANCE

      public static final HybridChronology INSTANCE
      Singleton instance for the Coptic chronology.

    • CUTOVER

      public static final LocalDate CUTOVER
      The cutover date, October 15, 1582.

  • Constructor Details

    • HybridChronology

      @Deprecated public HybridChronology()
      Deprecated.
      Use the singleton INSTANCE instead.
      Private constructor, that is public to satisfy the ServiceLoader.

  • Method Details

    • getCutover

      public LocalDate getCutover()
      Gets the cutover date between the Julian and Gregorian calendar.

      The date returned is the first date that the Gregorian (ISO) calendar applies, which is Thursday 14th September 1752.

      Returns:
      the first date after the cutover, not null

    • getId

      public String getId()
      Gets the ID of the chronology - 'Hybrid'.

      The ID uniquely identifies the Chronology. It can be used to lookup the Chronology using Chronology.of(String).

      Specified by:
      getId in interface Chronology
      Returns:
      the chronology ID - 'Hybrid'
      See Also:

    • getCalendarType

      public String getCalendarType()
      Gets the calendar type of the underlying calendar system, which returns null.

      The Unicode Locale Data Markup Language (LDML) specification does not define an identifier for this calendar system, thus null is returned.

      Specified by:
      getCalendarType in interface Chronology
      Returns:
      the calendar system type, null
      See Also:

    • date

      public HybridDate date(Era era, int yearOfEra, int month, int dayOfMonth)
      Obtains a local date in British Cutover calendar system from the era, year-of-era, month-of-year and day-of-month fields.

      Dates in the middle of the cutover gap, such as the 10th September 1752, will not throw an exception. Instead, the date will be treated as a Julian date and converted to an ISO date, with the day of month shifted by 11 days.

      Specified by:
      date in interface Chronology
      Parameters:
      era - the British Cutover era, not null
      yearOfEra - the year-of-era
      month - the month-of-year
      dayOfMonth - the day-of-month
      Returns:
      the British Cutover local date, not null
      Throws:
      DateTimeException - if unable to create the date
      ClassCastException - if the era is not a JulianEra

    • date

      public HybridDate date(int prolepticYear, int month, int dayOfMonth)
      Obtains a local date in British Cutover calendar system from the proleptic-year, month-of-year and day-of-month fields.

      Dates in the middle of the cutover gap, such as the 10th September 1752, will not throw an exception. Instead, the date will be treated as a Julian date and converted to an ISO date, with the day of month shifted by 11 days.

      Specified by:
      date in interface Chronology
      Parameters:
      prolepticYear - the proleptic-year
      month - the month-of-year
      dayOfMonth - the day-of-month
      Returns:
      the British Cutover local date, not null
      Throws:
      DateTimeException - if unable to create the date

    • dateYearDay

      public HybridDate dateYearDay(Era era, int yearOfEra, int dayOfYear)
      Obtains a local date in British Cutover calendar system from the era, year-of-era and day-of-year fields.

      The day-of-year takes into account the cutover, thus there are only 355 days in 1752.

      Specified by:
      dateYearDay in interface Chronology
      Parameters:
      era - the British Cutover era, not null
      yearOfEra - the year-of-era
      dayOfYear - the day-of-year
      Returns:
      the British Cutover local date, not null
      Throws:
      DateTimeException - if unable to create the date
      ClassCastException - if the era is not a JulianEra

    • dateYearDay

      public HybridDate dateYearDay(int prolepticYear, int dayOfYear)
      Obtains a local date in British Cutover calendar system from the proleptic-year and day-of-year fields.

      The day-of-year takes into account the cutover, thus there are only 355 days in 1752.

      Specified by:
      dateYearDay in interface Chronology
      Parameters:
      prolepticYear - the proleptic-year
      dayOfYear - the day-of-year
      Returns:
      the British Cutover local date, not null
      Throws:
      DateTimeException - if unable to create the date

    • dateEpochDay

      public HybridDate dateEpochDay(long epochDay)
      Obtains a local date in the British Cutover calendar system from the epoch-day.
      Specified by:
      dateEpochDay in interface Chronology
      Parameters:
      epochDay - the epoch day
      Returns:
      the British Cutover local date, not null
      Throws:
      DateTimeException - if unable to create the date

    • dateNow

      public HybridDate dateNow()
      Obtains the current British Cutover local date from the system clock in the default time-zone.

      This will query the system clock 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.

      Specified by:
      dateNow in interface Chronology
      Returns:
      the current British Cutover local date using the system clock and default time-zone, not null
      Throws:
      DateTimeException - if unable to create the date

    • dateNow

      public HybridDate dateNow(ZoneId zone)
      Obtains the current British Cutover local date from the system clock in the specified time-zone.

      This will query the system clock 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.

      Specified by:
      dateNow in interface Chronology
      Parameters:
      zone - the zone ID to use, not null
      Returns:
      the current British Cutover local date using the system clock, not null
      Throws:
      DateTimeException - if unable to create the date

    • dateNow

      public HybridDate dateNow(Clock clock)
      Obtains the current British Cutover 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:
      dateNow in interface Chronology
      Parameters:
      clock - the clock to use, not null
      Returns:
      the current British Cutover local date, not null
      Throws:
      DateTimeException - if unable to create the date

    • date

      public HybridDate date(TemporalAccessor temporal)
      Obtains a British Cutover local date from another date-time object.
      Specified by:
      date in interface Chronology
      Parameters:
      temporal - the date-time object to convert, not null
      Returns:
      the British Cutover local date, not null
      Throws:
      DateTimeException - if unable to create the date

    • localDateTime

      public ChronoLocalDateTime<HybridDate> localDateTime(TemporalAccessor temporal)
      Obtains a British Cutover local date-time from another date-time object.
      Specified by:
      localDateTime in interface Chronology
      Parameters:
      temporal - the date-time object to convert, not null
      Returns:
      the British Cutover local date-time, not null
      Throws:
      DateTimeException - if unable to create the date-time

    • zonedDateTime

      public ChronoZonedDateTime<HybridDate> zonedDateTime(TemporalAccessor temporal)
      Obtains a British Cutover zoned date-time from another date-time object.
      Specified by:
      zonedDateTime in interface Chronology
      Parameters:
      temporal - the date-time object to convert, not null
      Returns:
      the British Cutover zoned date-time, not null
      Throws:
      DateTimeException - if unable to create the date-time

    • zonedDateTime

      public ChronoZonedDateTime<HybridDate> zonedDateTime(Instant instant, ZoneId zone)
      Obtains a British Cutover zoned date-time in this chronology from an Instant.
      Specified by:
      zonedDateTime in interface Chronology
      Parameters:
      instant - the instant to create the date-time from, not null
      zone - the time-zone, not null
      Returns:
      the British Cutover zoned date-time, not null
      Throws:
      DateTimeException - if the result exceeds the supported range

    • isLeapYear

      public boolean isLeapYear(long prolepticYear)
      Checks if the specified year is a leap year.

      The result will return the same as JulianChronology.isLeapYear(long) for year 1752 and earlier, and IsoChronology.isLeapYear(long) otherwise. This method does not validate the year passed in, and only has a well-defined result for years in the supported range.

      Specified by:
      isLeapYear in interface Chronology
      Parameters:
      prolepticYear - the proleptic-year to check, not validated for range
      Returns:
      true if the year is a leap year

    • prolepticYear

      public int prolepticYear(Era era, int yearOfEra)
      Specified by:
      prolepticYear in interface Chronology

    • eraOf

      public JulianEra eraOf(int eraValue)
      Specified by:
      eraOf in interface Chronology

    • eras

      public List<Era> eras()
      Specified by:
      eras in interface Chronology

    • range

      public ValueRange range(ChronoField field)
      Specified by:
      range in interface Chronology

    • resolveDate

      public HybridDate resolveDate(Map<TemporalField,Long> fieldValues, ResolverStyle resolverStyle)
      Specified by:
      resolveDate in interface Chronology
      Overrides:
      resolveDate in class AbstractChronology