Class GJChronology

  • All Implemented Interfaces:
    java.io.Serializable

    public final class GJChronology
    extends AssembledChronology
    Implements the Gregorian/Julian calendar system which is the calendar system used in most of the world. Wherever possible, it is recommended to use the ISOChronology instead.

    The Gregorian calendar replaced the Julian calendar, and the point in time when this chronology switches can be controlled using the second parameter of the getInstance method. By default this cutover is set to the date the Gregorian calendar was first instituted, October 15, 1582.

    Before this date, this chronology uses the proleptic Julian calendar (proleptic means extending indefinitely). The Julian calendar has leap years every four years, whereas the Gregorian has special rules for 100 and 400 years. A meaningful result will thus be obtained for all input values. However before 8 CE, Julian leap years were irregular, and before 45 BCE there was no Julian calendar.

    This chronology differs from GregorianCalendar in that years in BCE are returned correctly. Thus year 1 BCE is returned as -1 instead of 1. The yearOfEra field produces results compatible with GregorianCalendar.

    The Julian calendar does not have a year zero, and so year -1 is followed by year 1. If the Gregorian cutover date is specified at or before year -1 (Julian), year zero is defined. In other words, the proleptic Gregorian chronology used by this class has a year zero.

    To create a pure proleptic Julian chronology, use JulianChronology, and to create a pure proleptic Gregorian chronology, use GregorianChronology.

    GJChronology is thread-safe and immutable.

    Since:
    1.0
    See Also:
    Serialized Form
    • Method Detail

      • getInstanceUTC

        public static GJChronology getInstanceUTC()
        Factory method returns instances of the default GJ cutover chronology. This uses a cutover date of October 15, 1582 (Gregorian) 00:00:00 UTC. For this value, October 4, 1582 (Julian) is followed by October 15, 1582 (Gregorian).

        The first day of the week is designated to be Monday, and the minimum days in the first week of the year is 4.

        The time zone of the returned instance is UTC.

      • getInstance

        public static GJChronology getInstance()
        Factory method returns instances of the default GJ cutover chronology. This uses a cutover date of October 15, 1582 (Gregorian) 00:00:00 UTC. For this value, October 4, 1582 (Julian) is followed by October 15, 1582 (Gregorian).

        The first day of the week is designated to be Monday, and the minimum days in the first week of the year is 4.

        The returned chronology is in the default time zone.

      • getInstance

        public static GJChronology getInstance​(DateTimeZone zone)
        Factory method returns instances of the GJ cutover chronology. This uses a cutover date of October 15, 1582 (Gregorian) 00:00:00 UTC. For this value, October 4, 1582 (Julian) is followed by October 15, 1582 (Gregorian).

        The first day of the week is designated to be Monday, and the minimum days in the first week of the year is 4.

        Parameters:
        zone - the time zone to use, null is default
      • getInstance

        public static GJChronology getInstance​(DateTimeZone zone,
                                               ReadableInstant gregorianCutover)
        Factory method returns instances of the GJ cutover chronology. Any cutover date may be specified.

        The first day of the week is designated to be Monday, and the minimum days in the first week of the year is 4.

        Parameters:
        zone - the time zone to use, null is default
        gregorianCutover - the cutover to use, null means default
      • getInstance

        public static GJChronology getInstance​(DateTimeZone zone,
                                               ReadableInstant gregorianCutover,
                                               int minDaysInFirstWeek)
        Factory method returns instances of the GJ cutover chronology. Any cutover date may be specified.
        Parameters:
        zone - the time zone to use, null is default
        gregorianCutover - the cutover to use, null means default
        minDaysInFirstWeek - minimum number of days in first week of the year; default is 4
      • getInstance

        public static GJChronology getInstance​(DateTimeZone zone,
                                               long gregorianCutover,
                                               int minDaysInFirstWeek)
        Factory method returns instances of the GJ cutover chronology. Any cutover date may be specified.
        Parameters:
        zone - the time zone to use, null is default
        gregorianCutover - the cutover to use
        minDaysInFirstWeek - minimum number of days in first week of the year; default is 4
      • getZone

        public DateTimeZone getZone()
        Description copied from class: BaseChronology
        Returns the DateTimeZone that this Chronology operates in, or null if unspecified.
        Overrides:
        getZone in class AssembledChronology
        Returns:
        DateTimeZone null if unspecified
      • withUTC

        public Chronology withUTC()
        Gets the Chronology in the UTC time zone.
        Specified by:
        withUTC in class BaseChronology
        Returns:
        the chronology in UTC
      • getDateTimeMillis

        public long getDateTimeMillis​(int year,
                                      int monthOfYear,
                                      int dayOfMonth,
                                      int millisOfDay)
                               throws java.lang.IllegalArgumentException
        Description copied from class: BaseChronology
        Returns a datetime millisecond instant, formed from the given year, month, day, and millisecond values. The set of given values must refer to a valid datetime, or else an IllegalArgumentException is thrown.

        The default implementation calls upon separate DateTimeFields to determine the result. Subclasses are encouraged to provide a more efficient implementation.

        Overrides:
        getDateTimeMillis in class AssembledChronology
        Parameters:
        year - year to use
        monthOfYear - month to use
        dayOfMonth - day of month to use
        millisOfDay - millisecond to use
        Returns:
        millisecond instant from 1970-01-01T00:00:00Z
        Throws:
        java.lang.IllegalArgumentException - if the values are invalid
      • getDateTimeMillis

        public long getDateTimeMillis​(int year,
                                      int monthOfYear,
                                      int dayOfMonth,
                                      int hourOfDay,
                                      int minuteOfHour,
                                      int secondOfMinute,
                                      int millisOfSecond)
                               throws java.lang.IllegalArgumentException
        Description copied from class: BaseChronology
        Returns a datetime millisecond instant, formed from the given year, month, day, hour, minute, second, and millisecond values. The set of given values must refer to a valid datetime, or else an IllegalArgumentException is thrown.

        The default implementation calls upon separate DateTimeFields to determine the result. Subclasses are encouraged to provide a more efficient implementation.

        Overrides:
        getDateTimeMillis in class AssembledChronology
        Parameters:
        year - year to use
        monthOfYear - month to use
        dayOfMonth - day of month to use
        hourOfDay - hour to use
        minuteOfHour - minute to use
        secondOfMinute - second to use
        millisOfSecond - millisecond to use
        Returns:
        millisecond instant from 1970-01-01T00:00:00Z
        Throws:
        java.lang.IllegalArgumentException - if the values are invalid
      • getGregorianCutover

        public Instant getGregorianCutover()
        Gets the cutover instant between Gregorian and Julian chronologies.
        Returns:
        the cutover instant
      • getMinimumDaysInFirstWeek

        public int getMinimumDaysInFirstWeek()
        Gets the minimum days needed for a week to be the first week in a year.
        Returns:
        the minimum days
      • equals

        public boolean equals​(java.lang.Object obj)
        Checks if this chronology instance equals another.
        Overrides:
        equals in class java.lang.Object
        Parameters:
        obj - the object to compare to
        Returns:
        true if equal
        Since:
        1.6
      • hashCode

        public int hashCode()
        A suitable hash code for the chronology.
        Overrides:
        hashCode in class java.lang.Object
        Returns:
        the hash code
        Since:
        1.6
      • toString

        public java.lang.String toString()
        Gets a debugging toString.
        Specified by:
        toString in class BaseChronology
        Returns:
        a debugging string