Package com.ibm.icu.impl

Class Grego

java.lang.Object

com.ibm.icu.impl.Grego

public class Grego
extends Object

A utility class providing proleptic Gregorian calendar functions used by time zone and calendar code. Do not instantiate. Note: Unlike GregorianCalendar, all computations performed by this class occur in the pure proleptic GregorianCalendar.

Field Summary

Fields

Modifier and Type	Field	Description
private static final int[]	DAYS_BEFORE
private static final int	JULIAN_1_CE
private static final int	JULIAN_1970_CE
static final long	MAX_MILLIS
static final int	MILLIS_PER_DAY
static final int	MILLIS_PER_HOUR
static final int	MILLIS_PER_MINUTE
static final int	MILLIS_PER_SECOND
static final long	MIN_MILLIS
private static final int[]	MONTH_LENGTH

Constructor Summary

Constructors

Constructor	Description
Grego()

Method Summary

Modifier and Type	Method	Description
static int	dayOfWeek(long day)	Return the day of week on the 1970-epoch day
static int[]	dayToFields(long day, int[] fields)
static long	fieldsToDay(int year, int month, int dom)	Convert a year, month, and day-of-month, given in the proleptic Gregorian calendar, to 1970 epoch days.
static long	floorDivide(long numerator, long denominator)
private static long	floorDivide(long numerator, long denominator, long[] remainder)
static int	getDayOfWeekInMonth(int year, int month, int dayOfMonth)
static final boolean	isLeapYear(int year)	Return true if the given year is a leap year.
static final int	monthLength(int year, int month)	Return the number of days in the given month.
static final int	previousMonthLength(int year, int month)	Return the length of a previous month of the Gregorian calendar.
static int[]	timeToFields(long time, int[] fields)
static String	timeToString(long time)	Convenient method for formatting time to ISO 8601 style date string.

Methods inherited from class java.lang.Object

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

Field Details

MIN_MILLIS

public static final long MIN_MILLIS

See Also:

• Constant Field Values

MAX_MILLIS

public static final long MAX_MILLIS

See Also:

• Constant Field Values

MILLIS_PER_SECOND

public static final int MILLIS_PER_SECOND

See Also:

• Constant Field Values

MILLIS_PER_MINUTE

public static final int MILLIS_PER_MINUTE

See Also:

• Constant Field Values

MILLIS_PER_HOUR

public static final int MILLIS_PER_HOUR

See Also:

• Constant Field Values

MILLIS_PER_DAY

public static final int MILLIS_PER_DAY

See Also:

• Constant Field Values

JULIAN_1_CE

private static final int JULIAN_1_CE

See Also:

• Constant Field Values

JULIAN_1970_CE

private static final int JULIAN_1970_CE

See Also:

• Constant Field Values

MONTH_LENGTH

private static final int[] MONTH_LENGTH

DAYS_BEFORE

private static final int[] DAYS_BEFORE

Constructor Details

Grego

public Grego()

Method Details

isLeapYear

public static final boolean isLeapYear(int year)

Return true if the given year is a leap year.

Parameters:

year - Gregorian year, with 0 == 1 BCE, -1 == 2 BCE, etc.

Returns:

true if the year is a leap year

monthLength

public static final int monthLength(int year,
 int month)

Return the number of days in the given month.

Parameters:

year - Gregorian year, with 0 == 1 BCE, -1 == 2 BCE, etc.

month - 0-based month, with 0==Jan

Returns:

the number of days in the given month

previousMonthLength

public static final int previousMonthLength(int year,
 int month)

Return the length of a previous month of the Gregorian calendar.

Parameters:

year - Gregorian year, with 0 == 1 BCE, -1 == 2 BCE, etc.

month - 0-based month, with 0==Jan

Returns:

the number of days in the month previous to the given month

fieldsToDay

public static long fieldsToDay(int year,
 int month,
 int dom)

Convert a year, month, and day-of-month, given in the proleptic Gregorian calendar, to 1970 epoch days.

Parameters:

year - Gregorian year, with 0 == 1 BCE, -1 == 2 BCE, etc.

month - 0-based month, with 0==Jan

dom - 1-based day of month

Returns:

the day number, with day 0 == Jan 1 1970

dayOfWeek

public static int dayOfWeek(long day)

Return the day of week on the 1970-epoch day

Parameters:

day - the 1970-epoch day (integral value)

Returns:

the day of week

dayToFields

public static int[] dayToFields(long day,
 int[] fields)

timeToFields

public static int[] timeToFields(long time,
 int[] fields)

floorDivide

public static long floorDivide(long numerator,
 long denominator)

floorDivide

private static long floorDivide(long numerator,
 long denominator,
 long[] remainder)

getDayOfWeekInMonth

public static int getDayOfWeekInMonth(int year,
 int month,
 int dayOfMonth)

timeToString

public static String timeToString(long time)

Convenient method for formatting time to ISO 8601 style date string.

Parameters:

time - long time

Returns:

ISO-8601 date string