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

Class Symmetry454Date

  • All Implemented Interfaces:
    Serializable, Comparable<ChronoLocalDate>, ChronoLocalDate, Temporal, TemporalAccessor, TemporalAdjuster
    public final class Symmetry454Date
extends Object
implements ChronoLocalDate, Serializable
    A date in the Symmetry454 calendar system.

    This date operates using the Symmetry454 calendar. This calendar system is a proposed reform calendar system, and is not in common use. The Symmetry454 calendar differs from the Gregorian in terms of month length, and the leap year rule. Dates are aligned such that 0001/01/01 (Sym454) is 0001-01-01 (ISO). The alignment of January 1st happens 40 times within a 293 years cycle, skipping 5, 6, 11 or 12 years in between: 1, 7, 18, 24, 29, 35, 46, 52, 57, 63, 74, 80, 85, 91, 103, 114, 120, 125, 131, 142, 148, 153, 159, 170, 176, 181, 187, 198, 210, 216, 221, 227, 238, 244, 249, 255, 266, 272, 277, 283.

    The implementation is a pure Symmetry454 calendar, as proposed by Dr. Irv Bromberg. The year shares the 12 months with the Gregorian calendar. The months February, May, August, November span 35 days, all other months consist of 28 days. In leap years, December is extended with a full week, the so-called "leap week". Since each month is made of full weeks, the calendar is perennial, with every date fixed always on the same weekday. Each month starts on a Monday and ends on a Sunday; so does each year. The 13th day of a month is always a Saturday.

    More information is available on Wikipedia at Symmetry454 or on the calendar's home page.

    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 Symmetry454Date now()
        Obtains the current Symmetry454Date 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 Symmetry454Date now​(ZoneId zone)
        Obtains the current Symmetry454Date 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 Symmetry454Date now​(Clock clock)
        Obtains the current Symmetry454Date 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 Symmetry454Date of​(int prolepticYear,
                                 int month,
                                 int dayOfMonth)
        Obtains a Symmetry454Date representing a date in the Symmetry454 calendar system from the proleptic-year, month-of-year and day-of-month fields.

        This returns a Symmetry454Date with the specified fields. The day must be valid for the year and month, otherwise an exception will be thrown.

        Parameters:
        prolepticYear - the Symmetry454 proleptic-year
        month - the Symmetry454 month-of-year, from 1 to 12
        dayOfMonth - the Symmetry454 day-of-month, from 1 to 28, or 1 to 35 in February, May, August, November and December in a Leap Year
        Returns:
        the date in Symmetry454 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 Symmetry454Date from​(TemporalAccessor temporal)
        Obtains a Symmetry454Date from a temporal object.

        This obtains a date in the Symmetry454 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 Symmetry454Date.

        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, Symmetry454Date::from.

        Parameters:
        temporal - the temporal object to convert, not null
        Returns:
        the date in the Symmetry454 calendar system, not null
        Throws:
        DateTimeException - if unable to convert to a Symmetry454Date

      • isLeapWeek

        public boolean isLeapWeek()
        Checks if the date is within the leap week.
        Returns:
        true if this date is in the leap week

      • getChronology

        public Symmetry454Chronology getChronology()
        Gets the chronology of this date, which is the Symmetry454 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 Symmetry454 chronology, not null

      • getEra

        public IsoEra getEra()
        Gets the era applicable at this date.

        The Symmetry454 calendar system uses IsoEra.

        Specified by:
        getEra in interface ChronoLocalDate
        Returns:
        the era applicable at this date, 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.

        Most months have 28 days, except for February, May, August, November, and December in a leap year, each has 35 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 do NOT match those of the ISO calendar system.

        Specified by:
        lengthOfYear in interface ChronoLocalDate
        Returns:
        the length of the year in days: 364 or 371

      • 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