Package net.time4j.base

Class GregorianMath

java.lang.Object
net.time4j.base.GregorianMath
public final class GregorianMath extends Object

Contains some calendrical tools for the rules of gregorian calendar.

Author:
Meno Hochschild

  • Field Summary

    Fields
    Modifier and Type
    Field
    Description
    static int
    MAX_YEAR
    Maximum of supported year range (999999999).
    static int
    MIN_YEAR
    Minimum of supported year range (-999999999).

  • Method Summary

    Modifier and Type
    Method
    Description
    static void
    checkDate​(int year, int month, int dayOfMonth)
    Checks the range limits of date values according to the rules of gregorian calendar.
    static int
    getDayOfWeek​(int year, int month, int dayOfMonth)
    Returns the day of week for given gregorian date.
    static int
    getLengthOfMonth​(int year, int month)
    Determines the maximum length of month in days dependent on given year (leap years!)
    static boolean
    isLeapYear​(int year)
    Queries if given year is a gregorian leap year.
    static boolean
    isValid​(int year, int month, int dayOfMonth)
    Queries if given values form a well defined gregorian date.
    static int
    readDayOfMonth​(long packedDate)
    Returns the day of month from given binary compressed date.
    static int
    readMonth​(long packedDate)
    Returns the month from given binary compressed date.
    static int
    readYear​(long packedDate)
    Returns the year from given binary compressed date.
    static long
    toMJD​(int year, int month, int dayOfMonth)
    Calculates the modified Julian date.
    static long
    toMJD​(GregorianDate date)
    Calculates the modified Julian date.
    static long
    toPackedDate​(long mjd)
    Calculates the gregorian Date based on given modified julian date in binary compressed format.

    Methods inherited from class java.lang.Object

    equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

  • Field Details

    • MIN_YEAR

      public static final int MIN_YEAR
      Minimum of supported year range (-999999999).
      See Also:
      Constant Field Values

    • MAX_YEAR

      public static final int MAX_YEAR
      Maximum of supported year range (999999999).
      See Also:
      Constant Field Values

  • Method Details

    • isLeapYear

      public static boolean isLeapYear​(int year)

      Queries if given year is a gregorian leap year.

      Parameters:
      year - number of proleptic year
      Returns:
      true if it is a leap year else false

    • getLengthOfMonth

      public static int getLengthOfMonth​(int year, int month)

      Determines the maximum length of month in days dependent on given year (leap years!) and month.

      Parameters:
      year - proleptic iso year
      month - gregorian month (1-12)
      Returns:
      length of month in days
      Throws:
      IllegalArgumentException - if month is out of range (1-12)

    • isValid

      public static boolean isValid​(int year, int month, int dayOfMonth)

      Queries if given values form a well defined gregorian date.

      This method only checks the range limits, not if the date is historically correct.

      Parameters:
      year - proleptic iso year [(-999999999) - 999999999]
      month - gregorian month (1-12)
      dayOfMonth - day of month (1-31)
      Returns:
      true if valid else false
      See Also:
      checkDate(int, int, int)

    • checkDate

      public static void checkDate​(int year, int month, int dayOfMonth)

      Checks the range limits of date values according to the rules of gregorian calendar.

      Parameters:
      year - proleptic iso year [(-999999999) - 999999999]
      month - gregorian month (1-12)
      dayOfMonth - day of month (1-31)
      Throws:
      IllegalArgumentException - if any argument is out of range
      See Also:
      isValid(int, int, int)

    • getDayOfWeek

      public static int getDayOfWeek​(int year, int month, int dayOfMonth)

      Returns the day of week for given gregorian date.

      This method is based on ISO-8601 and assumes that Monday is the first day of week.

      Parameters:
      year - proleptic iso year
      month - gregorian month (1-12)
      dayOfMonth - day of month (1-31)
      Returns:
      day of week (monday = 1, ..., sunday = 7)
      Throws:
      IllegalArgumentException - if the month or the day are out of range

    • readYear

      public static int readYear​(long packedDate)

      Returns the year from given binary compressed date.

      Parameters:
      packedDate - packed date in binary format
      Returns:
      proleptic iso year
      See Also:
      toPackedDate(long)

    • readMonth

      public static int readMonth​(long packedDate)

      Returns the month from given binary compressed date.

      Parameters:
      packedDate - packed date in binary format
      Returns:
      gregorian month (1-12)
      See Also:
      toPackedDate(long)

    • readDayOfMonth

      public static int readDayOfMonth​(long packedDate)

      Returns the day of month from given binary compressed date.

      Parameters:
      packedDate - packed date in binary format
      Returns:
      day of month (1-31)
      See Also:
      toPackedDate(long)

    • toPackedDate

      public static long toPackedDate​(long mjd)

      Calculates the gregorian Date based on given modified julian date in binary compressed format.

      Applications can extract the single date components from the result of this method by mean of readYear(), readMonth() and readDayOfMonth().

      Parameters:
      mjd - days since [1858-11-17] (modified Julian date)
      Returns:
      packed date in binary format
      Throws:
      IllegalArgumentException - if the calculated year is not in range [(-999999999)-999999999)]
      See Also:
      readYear(long), readMonth(long), readDayOfMonth(long)

    • toMJD

      public static long toMJD​(GregorianDate date)

      Calculates the modified Julian date.

      Parameters:
      date - gregorian date
      Returns:
      days since [1858-11-17] (modified Julian date)
      Throws:
      IllegalArgumentException - if the argument is out of range
      See Also:
      toMJD(int, int, int)

    • toMJD

      public static long toMJD​(int year, int month, int dayOfMonth)

      Calculates the modified Julian date.

      Parameters:
      year - proleptic iso year [(-999999999) - 999999999]
      month - gregorian month (1-12)
      dayOfMonth - day of month in range (1-31)
      Returns:
      days since [1858-11-17] (modified Julian date)
      Throws:
      IllegalArgumentException - if any argument is out of range