Module org.threeten.extra
Package org.threeten.extra.chrono

Class InternationalFixedDate

  • All Implemented Interfaces:
    Serializable, Comparable<ChronoLocalDate>, ChronoLocalDate, Temporal, TemporalAccessor, TemporalAdjuster
    public final class InternationalFixedDate
extends Object
implements ChronoLocalDate, Serializable
    A date in the International fixed calendar system.

    Implements a pure International Fixed calendar (also known as the Cotsworth plan, the Eastman plan, the 13 Month calendar or the Equal Month calendar) a solar calendar proposal for calendar reform designed by Moses B. Cotsworth, who presented it in 1902.

    It provides for a year of 13 months of 28 days each. Month 6 has 29 days in a leap year, but the additional day is not part of any week. Month 12 always has 29 days, but the additional day is not part of any week. It is therefore a perennial calendar, with every date fixed always on the same weekday. Though it was never officially adopted in any country, it was the official calendar of the Eastman Kodak Company from 1928 to 1989.

    This date operates using the International fixed calendar. This calendar system is a proposed reform calendar system, and is not in common use. The International fixed differs from the Gregorian in terms of month count and length, and the leap year rule. Dates are aligned such that 0001/01/01 (International fixed) is 0001-01-01 (ISO).

    More information is available in the International Fixed Calendar Wikipedia article.

    Implementation Requirements

    This class is immutable and thread-safe.

    This class must be treated as a value type. Do not synchronize, rely on the identity hash code or use the distinction between equals() and ==.

    See Also:
    Serialized Form

    • Method Detail

      • now

        public static InternationalFixedDate now()
        Obtains the current InternationalFixedDate 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.

        Returns:
        the current date using the system clock and default time-zone, not null

      • now

        public static InternationalFixedDate now​(ZoneId zone)
        Obtains the current InternationalFixedDate 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.

        Parameters:
        zone - the zone ID to use, not null
        Returns:
        the current date using the system clock, not null

      • now

        public static InternationalFixedDate now​(Clock clock)
        Obtains the current InternationalFixedDate 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.

        Parameters:
        clock - the clock to use, not null
        Returns:
        the current date, not null
        Throws:
        DateTimeException - if the current date cannot be obtained

      • of

        public static InternationalFixedDate of​(int prolepticYear,
                                        int month,
                                        int dayOfMonth)
        Obtains a InternationalFixedDate representing a date in the International fixed calendar system from the proleptic-year, month-of-year and day-of-month fields.

        This returns a InternationalFixedDate with the specified fields. The day must be valid for the year and month, otherwise an exception will be thrown.

        Parameters:
        prolepticYear - the International fixed proleptic-year
        month - the International fixed month-of-year, from 1 to 13
        dayOfMonth - the International fixed day-of-month, from 1 to 28 (29 for Leap Day or Year Day)
        Returns:
        the date in International fixed calendar system, not null
        Throws:
        DateTimeException - if the value of any field is out of range, or if the day-of-month is invalid for the month-year

      • from

        public static InternationalFixedDate from​(TemporalAccessor temporal)
        Obtains a InternationalFixedDate from a temporal object.

        This obtains a date in the International fixed calendar system based on the specified temporal. A TemporalAccessor represents an arbitrary set of date and time information, which this factory converts to an instance of InternationalFixedDate.

        The conversion typically uses the EPOCH_DAY field, which is standardized across calendar systems.

        This method matches the signature of the functional interface TemporalQuery allowing it to be used as a query via method reference, InternationalFixedDate::from.

        Parameters:
        temporal - the temporal object to convert, not null
        Returns:
        the date in the International fixed calendar system, not null
        Throws:
        DateTimeException - if unable to convert to a InternationalFixedDate

      • getChronology

        public InternationalFixedChronology getChronology()
        Gets the chronology of this date, which is the International fixed calendar system.

        The Chronology represents the calendar system in use. The era and other fields in ChronoField are defined by the chronology.

        Specified by:
        getChronology in interface ChronoLocalDate
        Returns:
        the International fixed chronology, not null

      • lengthOfMonth

        public int lengthOfMonth()
        Returns the length of the month represented by this date.

        This returns the length of the month in days. Month lengths do not match those of the ISO calendar system.

        Months have 28 days, except June which has 29 in leap years and December (month 13) which always has 29 days.

        Specified by:
        lengthOfMonth in interface ChronoLocalDate
        Returns:
        the length of the month in days

      • lengthOfYear

        public int lengthOfYear()
        Returns the length of the year represented by this date.

        This returns the length of the year in days. Year lengths match those of the ISO calendar system.

        Specified by:
        lengthOfYear in interface ChronoLocalDate
        Returns:
        the length of the year in days: 365 or 366

      • toString

        public String toString()
        Display the date in human-readable format.
        Specified by:
        toString in interface ChronoLocalDate
        Returns:
        the string representation

      • equals

        public boolean equals​(Object obj)
        Compares this date to another date, including the chronology.

        Compares this date with another ensuring that the date is the same.

        Only objects of this concrete type are compared, other types return false. To compare the dates of two TemporalAccessor instances, including dates in two different chronologies, use ChronoField.EPOCH_DAY as a comparator.

        Specified by:
        equals in interface ChronoLocalDate
        Overrides:
        equals in class Object
        Parameters:
        obj - the object to check, null returns false
        Returns:
        true if this is equal to the other date

      • hashCode

        public int hashCode()
        A hash code for this date.
        Specified by:
        hashCode in interface ChronoLocalDate
        Overrides:
        hashCode in class Object
        Returns:
        a suitable hash code based only on the Chronology and the date