com.ibm.icu.util

Class Calendar

public abstract class Calendar extends Object implements Serializable, Cloneable, Comparable

Calendar is an abstract base class for converting between a Date object and a set of integer fields such as YEAR, MONTH, DAY, HOUR, and so on. (A Date object represents a specific instant in time with millisecond precision. See {@link Date} for information about the Date class.)

Note: This class is similar, but not identical, to the class java.util.Calendar. Changes are detailed below.

Subclasses of Calendar interpret a Date according to the rules of a specific calendar system. ICU4J contains several subclasses implementing different international calendar systems.

Like other locale-sensitive classes, Calendar provides a class method, getInstance, for getting a generally useful object of this type. Calendar's getInstance method returns a calendar of a type appropriate to the locale, whose time fields have been initialized with the current date and time:

Calendar rightNow = Calendar.getInstance()

When a ULocale is used by getInstance, its 'calendar' tag and value are retrieved if present. If a recognized value is supplied, a calendar is provided and configured as appropriate. Currently recognized tags are "buddhist", "chinese", "coptic", "ethiopic", "gregorian", "hebrew", "islamic", "islamic-civil", and "japanese". For example:

Calendar cal = Calendar.getInstance(new ULocale("en_US@calendar=japanese"));
will return an instance of JapaneseCalendar (using en_US conventions for minimum days in first week, start day of week, et cetera).

A Calendar object can produce all the time field values needed to implement the date-time formatting for a particular language and calendar style (for example, Japanese-Gregorian, Japanese-Traditional). Calendar defines the range of values returned by certain fields, as well as their meaning. For example, the first month of the year has value MONTH == JANUARY for all calendars. Other values are defined by the concrete subclass, such as ERA and YEAR. See individual field documentation and subclass documentation for details.

When a Calendar is lenient, it accepts a wider range of field values than it produces. For example, a lenient GregorianCalendar interprets MONTH == JANUARY, DAY_OF_MONTH == 32 as February 1. A non-lenient GregorianCalendar throws an exception when given out-of-range field settings. When calendars recompute field values for return by get(), they normalize them. For example, a GregorianCalendar always produces DAY_OF_MONTH values between 1 and the length of the month.

Calendar defines a locale-specific seven day week using two parameters: the first day of the week and the minimal days in first week (from 1 to 7). These numbers are taken from the locale resource data when a Calendar is constructed. They may also be specified explicitly through the API.

When setting or getting the WEEK_OF_MONTH or WEEK_OF_YEAR fields, Calendar must determine the first week of the month or year as a reference point. The first week of a month or year is defined as the earliest seven day period beginning on getFirstDayOfWeek() and containing at least getMinimalDaysInFirstWeek() days of that month or year. Weeks numbered ..., -1, 0 precede the first week; weeks numbered 2, 3,... follow it. Note that the normalized numbering returned by get() may be different. For example, a specific Calendar subclass may designate the week before week 1 of a year as week n of the previous year.

When computing a Date from time fields, two special circumstances may arise: there may be insufficient information to compute the Date (such as only year and month but no day in the month), or there may be inconsistent information (such as "Tuesday, July 15, 1996" -- July 15, 1996 is actually a Monday).

Insufficient information. The calendar will use default information to specify the missing fields. This may vary by calendar; for the Gregorian calendar, the default for a field is the same as that of the start of the epoch: i.e., YEAR = 1970, MONTH = JANUARY, DATE = 1, etc.

Inconsistent information. If fields conflict, the calendar will give preference to fields set more recently. For example, when determining the day, the calendar will look for one of the following combinations of fields. The most recent combination, as determined by the most recently set single field, will be used.

 MONTH + DAY_OF_MONTH
 MONTH + WEEK_OF_MONTH + DAY_OF_WEEK
 MONTH + DAY_OF_WEEK_IN_MONTH + DAY_OF_WEEK
 DAY_OF_YEAR
 DAY_OF_WEEK + WEEK_OF_YEAR
For the time of day:
 HOUR_OF_DAY
 AM_PM + HOUR

Note: for some non-Gregorian calendars, different fields may be necessary for complete disambiguation. For example, a full specification of the historial Arabic astronomical calendar requires year, month, day-of-month and day-of-week in some cases.

Note: There are certain possible ambiguities in interpretation of certain singular times, which are resolved in the following ways:

  1. 24:00:00 "belongs" to the following day. That is, 23:59 on Dec 31, 1969 < 24:00 on Jan 1, 1970 < 24:01:00 on Jan 1, 1970
  2. Although historically not precise, midnight also belongs to "am", and noon belongs to "pm", so on the same day, 12:00 am (midnight) < 12:01 am, and 12:00 pm (noon) < 12:01 pm

The date or time format strings are not part of the definition of a calendar, as those must be modifiable or overridable by the user at runtime. Use {@link DateFormat} to format dates.

Field manipulation methods

Calendar fields can be changed using three methods: set(), add(), and roll().

set(f, value) changes field f to value. In addition, it sets an internal member variable to indicate that field f has been changed. Although field f is changed immediately, the calendar's milliseconds is not recomputed until the next call to get(), getTime(), or getTimeInMillis() is made. Thus, multiple calls to set() do not trigger multiple, unnecessary computations. As a result of changing a field using set(), other fields may also change, depending on the field, the field value, and the calendar system. In addition, get(f) will not necessarily return value after the fields have been recomputed. The specifics are determined by the concrete calendar class.

Example: Consider a GregorianCalendar originally set to August 31, 1999. Calling set(Calendar.MONTH, Calendar.SEPTEMBER) sets the calendar to September 31, 1999. This is a temporary internal representation that resolves to October 1, 1999 if getTime()is then called. However, a call to set(Calendar.DAY_OF_MONTH, 30) before the call to getTime() sets the calendar to September 30, 1999, since no recomputation occurs after set() itself.

add(f, delta) adds delta to field f. This is equivalent to calling set(f, get(f) + delta) with two adjustments:

Add rule 1. The value of field f after the call minus the value of field f before the call is delta, modulo any overflow that has occurred in field f. Overflow occurs when a field value exceeds its range and, as a result, the next larger field is incremented or decremented and the field value is adjusted back into its range.

Add rule 2. If a smaller field is expected to be invariant, but   it is impossible for it to be equal to its prior value because of changes in its minimum or maximum after field f is changed, then its value is adjusted to be as close as possible to its expected value. A smaller field represents a smaller unit of time. HOUR is a smaller field than DAY_OF_MONTH. No adjustment is made to smaller fields that are not expected to be invariant. The calendar system determines what fields are expected to be invariant.

In addition, unlike set(), add() forces an immediate recomputation of the calendar's milliseconds and all fields.

Example: Consider a GregorianCalendar originally set to August 31, 1999. Calling add(Calendar.MONTH, 13) sets the calendar to September 30, 2000. Add rule 1 sets the MONTH field to September, since adding 13 months to August gives September of the next year. Since DAY_OF_MONTH cannot be 31 in September in a GregorianCalendar, add rule 2 sets the DAY_OF_MONTH to 30, the closest possible value. Although it is a smaller field, DAY_OF_WEEK is not adjusted by rule 2, since it is expected to change when the month changes in a GregorianCalendar.

roll(f, delta) adds delta to field f without changing larger fields. This is equivalent to calling add(f, delta) with the following adjustment:

Roll rule. Larger fields are unchanged after the call. A larger field represents a larger unit of time. DAY_OF_MONTH is a larger field than HOUR.

Example: Consider a GregorianCalendar originally set to August 31, 1999. Calling roll(Calendar.MONTH, 8) sets the calendar to April 30, 1999. Add rule 1 sets the MONTH field to April. Using a GregorianCalendar, the DAY_OF_MONTH cannot be 31 in the month April. Add rule 2 sets it to the closest possible value, 30. Finally, the roll rule maintains the YEAR field value of 1999.

Example: Consider a GregorianCalendar originally set to Sunday June 6, 1999. Calling roll(Calendar.WEEK_OF_MONTH, -1) sets the calendar to Tuesday June 1, 1999, whereas calling add(Calendar.WEEK_OF_MONTH, -1) sets the calendar to Sunday May 30, 1999. This is because the roll rule imposes an additional constraint: The MONTH must not change when the WEEK_OF_MONTH is rolled. Taken together with add rule 1, the resultant date must be between Tuesday June 1 and Saturday June 5. According to add rule 2, the DAY_OF_WEEK, an invariant when changing the WEEK_OF_MONTH, is set to Tuesday, the closest possible value to Sunday (where Sunday is the first day of the week).

Usage model. To motivate the behavior of add() and roll(), consider a user interface component with increment and decrement buttons for the month, day, and year, and an underlying GregorianCalendar. If the interface reads January 31, 1999 and the user presses the month increment button, what should it read? If the underlying implementation uses set(), it might read March 3, 1999. A better result would be February 28, 1999. Furthermore, if the user presses the month increment button again, it should read March 31, 1999, not March 28, 1999. By saving the original date and using either add() or roll(), depending on whether larger fields should be affected, the user interface can behave as most users will intuitively expect.

Note: You should always use {@link #roll roll} and {@link #add add} rather than attempting to perform arithmetic operations directly on the fields of a Calendar. It is quite possible for Calendar subclasses to have fields with non-linear behavior, for example missing months or days during non-leap years. The subclasses' add and roll methods will take this into account, while simple arithmetic manipulations may give invalid results.

Calendar Architecture in ICU4J

Recently the implementation of Calendar has changed significantly in order to better support subclassing. The original Calendar class was designed to support subclassing, but it had only one implemented subclass, GregorianCalendar. With the implementation of several new calendar subclasses, including the BuddhistCalendar, ChineseCalendar, HebrewCalendar, IslamicCalendar, and JapaneseCalendar, the subclassing API has been reworked thoroughly. This section details the new subclassing API and other ways in which com.ibm.icu.util.Calendar differs from java.util.Calendar.

Changes

Overview of changes between the classic Calendar architecture and the new architecture.

Subclass API

The original Calendar API was based on the experience of implementing a only a single subclass, GregorianCalendar. As a result, all of the subclassing kinks had not been worked out. The new subclassing API has been refined based on several implemented subclasses. This includes methods that must be overridden and methods for subclasses to call. Subclasses no longer have direct access to fields and stamp. Instead, they have new API to access these. Subclasses are able to allocate the fields array through a protected framework method; this allows subclasses to specify additional fields.

More functionality has been moved into the base class. The base class now contains much of the computational machinery to support the Gregorian calendar. This is based on two things: (1) Many calendars are based on the Gregorian calendar (such as the Buddhist and Japanese imperial calendars). (2) All calendars require basic Gregorian support in order to handle timezone computations.

Common computations have been moved into Calendar. Subclasses no longer compute the week related fields and the time related fields. These are commonly handled for all calendars by the base class.

Subclass computation of time => fields

The {@link #ERA}, {@link #YEAR}, {@link #EXTENDED_YEAR}, {@link #MONTH}, {@link #DAY_OF_MONTH}, and {@link #DAY_OF_YEAR} fields are computed by the subclass, based on the Julian day. All other fields are computed by Calendar.

Subclass computation of fields => time

The interpretation of most field values is handled entirely by Calendar. Calendar determines which fields are set, which are not, which are set more recently, and so on. In addition, Calendar handles the computation of the time from the time fields and handles the week-related fields. The only thing the subclass must do is determine the extended year, based on the year fields, and then, given an extended year and a month, it must return a Julian day number.

Other methods

Normalized behavior

The behavior of certain fields has been made consistent across all calendar systems and implemented in Calendar.

Supported range

The allowable range of Calendar has been narrowed. GregorianCalendar used to attempt to support the range of dates with millisecond values from Long.MIN_VALUE to Long.MAX_VALUE. This introduced awkward constructions (hacks) which slowed down performance. It also introduced non-uniform behavior at the boundaries. The new Calendar protocol specifies the maximum range of supportable dates as those having Julian day numbers of -0x7F000000 to +0x7F000000. This corresponds to years from ~5,000,000 BCE to ~5,000,000 CE. Programmers should use the constants {@link #MIN_DATE} (or {@link #MIN_MILLIS} or {@link #MIN_JULIAN}) and {@link #MAX_DATE} (or {@link #MAX_MILLIS} or {@link #MAX_JULIAN}) in Calendar to specify an extremely early or extremely late date.

General notes

Author: Mark Davis, David Goldsmith, Chen-Lieh Huang, Alan Liu, Laura Werner

See Also: Date GregorianCalendar TimeZone DateFormat

UNKNOWN: ICU 2.0

Field Summary
static intAM
Value of the AM_PM field indicating the period of the day from midnight to just before noon.
static intAM_PM
Field number for get and set indicating whether the HOUR is before or after noon.
static intAPRIL
Value of the MONTH field indicating the fourth month of the year.
static intAUGUST
Value of the MONTH field indicating the eighth month of the year.
protected static intBASE_FIELD_COUNT
The number of fields defined by this class.
static intDATE
Field number for get and set indicating the day of the month.
static intDAY_OF_MONTH
Field number for get and set indicating the day of the month.
static intDAY_OF_WEEK
Field number for get and set indicating the day of the week.
static intDAY_OF_WEEK_IN_MONTH
Field number for get and set indicating the ordinal number of the day of the week within the current month.
static intDAY_OF_YEAR
Field number for get and set indicating the day number within the current year.
static intDECEMBER
Value of the MONTH field indicating the twelfth month of the year.
static intDOW_LOCAL
Field number for get() and set() indicating the localized day of week.
static intDST_OFFSET
Field number for get and set indicating the daylight savings offset in milliseconds.
protected static intEPOCH_JULIAN_DAY
The Julian day of the epoch, that is, January 1, 1970 on the Gregorian calendar.
static intERA
Field number for get and set indicating the era, e.g., AD or BC in the Julian calendar.
static intEXTENDED_YEAR
Field number for get() and set() indicating the extended year.
static intFEBRUARY
Value of the MONTH field indicating the second month of the year.
static intFRIDAY
Value of the DAY_OF_WEEK field indicating Friday.
protected static intGREATEST_MINIMUM
Limit type for getLimit() and handleGetLimit() indicating the greatest minimum value that a field can take.
static intHOUR
Field number for get and set indicating the hour of the morning or afternoon.
static intHOUR_OF_DAY
Field number for get and set indicating the hour of the day.
protected static intINTERNALLY_SET
Value of the time stamp stamp[] indicating that a field has been set via computations from the time or from other fields.
static intJANUARY
Value of the MONTH field indicating the first month of the year.
protected static intJAN_1_1_JULIAN_DAY
The Julian day of the Gregorian epoch, that is, January 1, 1 on the Gregorian calendar.
static intJULIAN_DAY
Field number for get() and set() indicating the modified Julian day number.
static intJULY
Value of the MONTH field indicating the seventh month of the year.
static intJUNE
Value of the MONTH field indicating the sixth month of the year.
protected static intLEAST_MAXIMUM
Limit type for getLimit() and handleGetLimit() indicating the least maximum value that a field can take.
static intMARCH
Value of the MONTH field indicating the third month of the year.
protected static intMAXIMUM
Limit type for getLimit() and handleGetLimit() indicating the maximum value that a field can take (greatest maximum).
protected static DateMAX_DATE
The maximum supported Date.
protected static intMAX_FIELD_COUNT
The maximum number of fields possible.
protected static intMAX_JULIAN
The maximum supported Julian day.
protected static longMAX_MILLIS
The maximum supported epoch milliseconds.
static intMAY
Value of the MONTH field indicating the fifth month of the year.
static intMILLISECOND
Field number for get and set indicating the millisecond within the second.
static intMILLISECONDS_IN_DAY
Field number for get() and set() indicating the milliseconds in the day.
protected static intMINIMUM
Limit type for getLimit() and handleGetLimit() indicating the minimum value that a field can take (least minimum).
protected static intMINIMUM_USER_STAMP
If the time stamp stamp[] has a value greater than or equal to MINIMUM_USER_SET then it has been set by the user via a call to set().
static intMINUTE
Field number for get and set indicating the minute within the hour.
protected static DateMIN_DATE
The minimum supported Date.
protected static intMIN_JULIAN
The minimum supported Julian day.
protected static longMIN_MILLIS
The minimum supported epoch milliseconds.
static intMONDAY
Value of the DAY_OF_WEEK field indicating Monday.
static intMONTH
Field number for get and set indicating the month.
static intNOVEMBER
Value of the MONTH field indicating the eleventh month of the year.
static intOCTOBER
Value of the MONTH field indicating the tenth month of the year.
protected static longONE_DAY
The number of milliseconds in one day.
protected static intONE_HOUR
The number of milliseconds in one hour.
protected static intONE_MINUTE
The number of milliseconds in one minute.
protected static intONE_SECOND
The number of milliseconds in one second.
protected static longONE_WEEK
The number of milliseconds in one week.
static intPM
Value of the AM_PM field indicating the period of the day from noon to just before midnight.
protected static intRESOLVE_REMAP
Value to OR against resolve table field values for remapping.
static intSATURDAY
Value of the DAY_OF_WEEK field indicating Saturday.
static intSECOND
Field number for get and set indicating the second within the minute.
static intSEPTEMBER
Value of the MONTH field indicating the ninth month of the year.
static intSUNDAY
Value of the DAY_OF_WEEK field indicating Sunday.
static intTHURSDAY
Value of the DAY_OF_WEEK field indicating Thursday.
static intTUESDAY
Value of the DAY_OF_WEEK field indicating Tuesday.
static intUNDECIMBER
Value of the MONTH field indicating the thirteenth month of the year.
protected static intUNSET
Value of the time stamp stamp[] indicating that a field has not been set since the last call to clear().
static intWEDNESDAY
Value of the DAY_OF_WEEK field indicating Wednesday.
static intWEEKDAY
Value returned by getDayOfWeekType(int dayOfWeek) to indicate a weekday.
static intWEEKEND
Value returned by getDayOfWeekType(int dayOfWeek) to indicate a weekend day.
static intWEEKEND_CEASE
Value returned by getDayOfWeekType(int dayOfWeek) to indicate a day that starts as the weekend and transitions to a weekday.
static intWEEKEND_ONSET
Value returned by getDayOfWeekType(int dayOfWeek) to indicate a day that starts as a weekday and transitions to the weekend.
static intWEEK_OF_MONTH
Field number for get and set indicating the week number within the current month.
static intWEEK_OF_YEAR
Field number for get and set indicating the week number within the current year.
static intYEAR
Field number for get and set indicating the year.
static intYEAR_WOY
Field number for get() and set() indicating the extended year corresponding to the WEEK_OF_YEAR field.
static intZONE_OFFSET
Field number for get and set indicating the raw offset from GMT in milliseconds.
Constructor Summary
protected Calendar()
Constructs a Calendar with the default time zone and locale.
protected Calendar(TimeZone zone, Locale aLocale)
Constructs a calendar with the specified time zone and locale.
protected Calendar(TimeZone zone, ULocale locale)
Constructs a calendar with the specified time zone and locale.
Method Summary
voidadd(int field, int amount)
Add a signed amount to a specified field, using this calendar's rules.
booleanafter(Object when)
Compares the time field records.
booleanbefore(Object when)
Compares the time field records.
voidclear()
Clears the values of all the time fields.
voidclear(int field)
Clears the value in the given time field.
Objectclone()
Overrides Cloneable
intcompareTo(Calendar that)
Compares the times (in millis) represented by two Calendar objects.
intcompareTo(Object that)
Implement comparable API as a convenience override of {@link #compareTo(Calendar)}.
protected voidcomplete()
Fills in any unset fields in the time field list.
protected voidcomputeFields()
Converts the current millisecond time value time to field values in fields[].
protected voidcomputeGregorianFields(int julianDay)
Compute the Gregorian calendar year, month, and day of month from the Julian day.
protected intcomputeGregorianMonthStart(int year, int month)
Compute the Julian day of a month of the Gregorian calendar.
protected intcomputeJulianDay()
Compute the Julian day number as specified by this calendar's fields.
protected intcomputeMillisInDay()
Compute the milliseconds in the day from the fields.
protected voidcomputeTime()
Converts the current field values in fields[] to the millisecond time value time.
protected intcomputeZoneOffset(long millis, int millisInDay)
This method can assume EXTENDED_YEAR has been set.
booleanequals(Object obj)
Compares this calendar to the specified object.
intfieldDifference(Date when, int field)
[NEW] Return the difference between the given time and the time this calendar object is set to.
protected StringfieldName(int field)
Return a string name for a field, for debugging and exceptions.
protected static longfloorDivide(long numerator, long denominator)
Divide two long integers, returning the floor of the quotient.
protected static intfloorDivide(int numerator, int denominator)
Divide two integers, returning the floor of the quotient.
protected static intfloorDivide(int numerator, int denominator, int[] remainder)
Divide two integers, returning the floor of the quotient, and the modulus remainder.
protected static intfloorDivide(long numerator, int denominator, int[] remainder)
Divide two integers, returning the floor of the quotient, and the modulus remainder.
intget(int field)
Gets the value for a given time field.
intgetActualMaximum(int field)
Return the maximum value that this field could have, given the current date.
intgetActualMinimum(int field)
Return the minimum value that this field could have, given the current date.
static Locale[]getAvailableLocales()
Gets the list of locales for which Calendars are installed.
static ULocale[]getAvailableULocales()
Gets the list of locales for which Calendars are installed.
DateFormatgetDateTimeFormat(int dateStyle, int timeStyle, Locale loc)
Return a DateFormat appropriate to this calendar.
DateFormatgetDateTimeFormat(int dateStyle, int timeStyle, ULocale loc)
Return a DateFormat appropriate to this calendar.
intgetDayOfWeekType(int dayOfWeek)
Return whether the given day of the week is a weekday, a weekend day, or a day that transitions from one to the other, in this calendar system.
StringgetDisplayName(Locale loc)
Return the name of this calendar in the language of the given locale.
StringgetDisplayName(ULocale loc)
Return the name of this calendar in the language of the given locale.
intgetFieldCount()
Return the number of fields defined by this calendar.
protected int[][][]getFieldResolutionTable()
Return the field resolution array for this calendar.
intgetFirstDayOfWeek()
Gets what the first day of the week is; e.g., Sunday in US, Monday in France.
intgetGreatestMinimum(int field)
Gets the highest minimum value for the given field if varies.
protected intgetGregorianDayOfMonth()
Return the day of month (1-based) on the Gregorian calendar as computed by computeGregorianFields().
protected intgetGregorianDayOfYear()
Return the day of year (1-based) on the Gregorian calendar as computed by computeGregorianFields().
protected intgetGregorianMonth()
Return the month (0-based) on the Gregorian calendar as computed by computeGregorianFields().
protected intgetGregorianYear()
Return the extended year on the Gregorian calendar as computed by computeGregorianFields().
static CalendargetInstance()
Gets a calendar using the default time zone and locale.
static CalendargetInstance(TimeZone zone)
Gets a calendar using the specified time zone and default locale.
static CalendargetInstance(Locale aLocale)
Gets a calendar using the default time zone and specified locale.
static CalendargetInstance(ULocale locale)
Gets a calendar using the default time zone and specified locale.
static CalendargetInstance(TimeZone zone, Locale aLocale)
Gets a calendar with the specified time zone and locale.
static CalendargetInstance(TimeZone zone, ULocale locale)
Gets a calendar with the specified time zone and locale.
intgetLeastMaximum(int field)
Gets the lowest maximum value for the given field if varies.
protected intgetLimit(int field, int limitType)
Return a limit for a field.
ULocalegetLocale(ULocale.Type type)
Return the locale that was used to create this object, or null.
intgetMaximum(int field)
Gets the maximum value for the given time field. e.g. for Gregorian DAY_OF_MONTH, 31.
intgetMinimalDaysInFirstWeek()
Gets what the minimal days required in the first week of the year are; e.g., if the first week is defined as one that contains the first day of the first month of a year, getMinimalDaysInFirstWeek returns 1.
intgetMinimum(int field)
Gets the minimum value for the given time field. e.g., for Gregorian DAY_OF_MONTH, 1.
protected intgetStamp(int field)
Return the timestamp of a field.
DategetTime()
Gets this Calendar's current time.
longgetTimeInMillis()
Gets this Calendar's current time as a long.
TimeZonegetTimeZone()
Gets the time zone.
StringgetType()
Return the current Calendar type.
intgetWeekendTransition(int dayOfWeek)
Return the time during the day at which the weekend begins or end in this calendar system.
protected static intgregorianMonthLength(int y, int m)
Return the length of a month of the Gregorian calendar.
protected static intgregorianPreviousMonthLength(int y, int m)
Return the length of a previous month of the Gregorian calendar.
protected voidhandleComputeFields(int julianDay)
Subclasses may override this method to compute several fields specific to each calendar system.
protected inthandleComputeJulianDay(int bestField)
Subclasses may override this.
protected abstract inthandleComputeMonthStart(int eyear, int month, boolean useMonth)
Return the Julian day number of day before the first day of the given month in the given extended year.
protected int[]handleCreateFields()
Subclasses that use additional fields beyond those defined in Calendar should override this method to return an int[] array of the appropriate length.
protected DateFormathandleGetDateFormat(String pattern, Locale locale)
Create a DateFormat appropriate to this calendar.
protected DateFormathandleGetDateFormat(String pattern, ULocale locale)
Create a DateFormat appropriate to this calendar.
protected abstract inthandleGetExtendedYear()
Return the extended year defined by the current fields.
protected abstract inthandleGetLimit(int field, int limitType)
Subclass API for defining limits of different types.
protected inthandleGetMonthLength(int extendedYear, int month)
Return the number of days in the given month of the given extended year of this calendar system.
protected inthandleGetYearLength(int eyear)
Return the number of days in the given extended year of this calendar system.
inthashCode()
Returns a hash code for this calendar.
protected intinternalGet(int field)
Gets the value for a given time field.
protected intinternalGet(int field, int defaultValue)
Get the value for a given time field, or return the given default value if the field is not set.
protected longinternalGetTimeInMillis()
Return the current milliseconds without recomputing.
protected voidinternalSet(int field, int value)
Set a field to a value.
booleanisEquivalentTo(Calendar other)
Returns true if the given Calendar object is equivalent to this one.
protected static booleanisGregorianLeapYear(int year)
Determines if the given year is a leap year.
booleanisLenient()
Tell whether date/time interpretation is to be lenient.
booleanisSet(int field)
Determines if the given time field has a value set.
booleanisWeekend(Date date)
Return true if the given date and time is in the weekend in this calendar system.
booleanisWeekend()
Return true if this Calendar's current date and time is in the weekend in this calendar system.
protected static intjulianDayToDayOfWeek(int julian)
Return the day of week, from SUNDAY to SATURDAY, given a Julian day.
protected static longjulianDayToMillis(int julian)
Converts Julian day to time as milliseconds.
protected static intmillisToJulianDay(long millis)
Converts time as milliseconds to Julian day.
protected intnewerField(int defaultField, int alternateField)
Return the field that is newer, either defaultField, or alternateField.
protected intnewestStamp(int first, int last, int bestStampSoFar)
Return the newest stamp of a given range of fields.
protected voidpinField(int field)
Adjust the specified field so that it is within the allowable range for the date to which this calendar is set.
protected voidprepareGetActual(int field, boolean isMinimum)
Prepare this calendar for computing the actual minimum or maximum.
protected intresolveFields(int[][][] precedenceTable)
Given a precedence table, return the newest field combination in the table, or -1 if none is found.
voidroll(int field, boolean up)
Rolls (up/down) a single unit of time on the given field.
voidroll(int field, int amount)
Rolls (up/down) a specified amount time on the given field.
voidset(int field, int value)
Sets the time field with the given value.
voidset(int year, int month, int date)
Sets the values for the fields year, month, and date.
voidset(int year, int month, int date, int hour, int minute)
Sets the values for the fields year, month, date, hour, and minute.
voidset(int year, int month, int date, int hour, int minute, int second)
Sets the values for the fields year, month, date, hour, minute, and second.
voidsetFirstDayOfWeek(int value)
Sets what the first day of the week is; e.g., Sunday in US, Monday in France.
voidsetLenient(boolean lenient)
Specify whether or not date/time interpretation is to be lenient.
voidsetMinimalDaysInFirstWeek(int value)
Sets what the minimal days required in the first week of the year are.
voidsetTime(Date date)
Sets this Calendar's current time with the given Date.
voidsetTimeInMillis(long millis)
Sets this Calendar's current time from the given long value.
voidsetTimeZone(TimeZone value)
Sets the time zone with the given time zone value.
StringtoString()
Return a string representation of this calendar.
protected voidvalidateField(int field)
Validate a single field of this calendar.
protected voidvalidateField(int field, int min, int max)
Validate a single field of this calendar given its minimum and maximum allowed value.
protected voidvalidateFields()
Ensure that each field is within its valid range by calling {@link #validateField(int)} on each field that has been set.
protected intweekNumber(int desiredDay, int dayOfPeriod, int dayOfWeek)
Return the week number of a day, within a period.
protected intweekNumber(int dayOfPeriod, int dayOfWeek)
Return the week number of a day, within a period.

Field Detail

AM

public static final int AM
Value of the AM_PM field indicating the period of the day from midnight to just before noon.

UNKNOWN: ICU 2.0

AM_PM

public static final int AM_PM
Field number for get and set indicating whether the HOUR is before or after noon. E.g., at 10:04:15.250 PM the AM_PM is PM.

See Also: AM PM HOUR

UNKNOWN: ICU 2.0

APRIL

public static final int APRIL
Value of the MONTH field indicating the fourth month of the year.

UNKNOWN: ICU 2.0

AUGUST

public static final int AUGUST
Value of the MONTH field indicating the eighth month of the year.

UNKNOWN: ICU 2.0

BASE_FIELD_COUNT

protected static final int BASE_FIELD_COUNT
The number of fields defined by this class. Subclasses may define addition fields starting with this number.

UNKNOWN: ICU 2.0

DATE

public static final int DATE
Field number for get and set indicating the day of the month. This is a synonym for DAY_OF_MONTH. The first day of the month has value 1.

See Also: DAY_OF_MONTH

UNKNOWN: ICU 2.0

DAY_OF_MONTH

public static final int DAY_OF_MONTH
Field number for get and set indicating the day of the month. This is a synonym for DATE. The first day of the month has value 1.

See Also: DATE

UNKNOWN: ICU 2.0

DAY_OF_WEEK

public static final int DAY_OF_WEEK
Field number for get and set indicating the day of the week. This field takes values SUNDAY, MONDAY, TUESDAY, WEDNESDAY, THURSDAY, FRIDAY, and SATURDAY.

See Also: SUNDAY MONDAY TUESDAY WEDNESDAY THURSDAY FRIDAY SATURDAY

UNKNOWN: ICU 2.0

DAY_OF_WEEK_IN_MONTH

public static final int DAY_OF_WEEK_IN_MONTH
Field number for get and set indicating the ordinal number of the day of the week within the current month. Together with the DAY_OF_WEEK field, this uniquely specifies a day within a month. Unlike WEEK_OF_MONTH and WEEK_OF_YEAR, this field's value does not depend on getFirstDayOfWeek() or getMinimalDaysInFirstWeek(). DAY_OF_MONTH 1 through 7 always correspond to DAY_OF_WEEK_IN_MONTH 1; 8 through 15 correspond to DAY_OF_WEEK_IN_MONTH 2, and so on. DAY_OF_WEEK_IN_MONTH 0 indicates the week before DAY_OF_WEEK_IN_MONTH 1. Negative values count back from the end of the month, so the last Sunday of a month is specified as DAY_OF_WEEK = SUNDAY, DAY_OF_WEEK_IN_MONTH = -1. Because negative values count backward they will usually be aligned differently within the month than positive values. For example, if a month has 31 days, DAY_OF_WEEK_IN_MONTH -1 will overlap DAY_OF_WEEK_IN_MONTH 5 and the end of 4.

See Also: DAY_OF_WEEK WEEK_OF_MONTH

UNKNOWN: ICU 2.0

DAY_OF_YEAR

public static final int DAY_OF_YEAR
Field number for get and set indicating the day number within the current year. The first day of the year has value 1.

UNKNOWN: ICU 2.0

DECEMBER

public static final int DECEMBER
Value of the MONTH field indicating the twelfth month of the year.

UNKNOWN: ICU 2.0

DOW_LOCAL

public static final int DOW_LOCAL
Field number for get() and set() indicating the localized day of week. This will be a value from 1 to 7 inclusive, with 1 being the localized first day of the week.

UNKNOWN: ICU 2.0

DST_OFFSET

public static final int DST_OFFSET
Field number for get and set indicating the daylight savings offset in milliseconds.

UNKNOWN: ICU 2.0

EPOCH_JULIAN_DAY

protected static final int EPOCH_JULIAN_DAY
The Julian day of the epoch, that is, January 1, 1970 on the Gregorian calendar.

UNKNOWN: ICU 2.0

ERA

public static final int ERA
Field number for get and set indicating the era, e.g., AD or BC in the Julian calendar. This is a calendar-specific value; see subclass documentation.

See Also: AD BC

UNKNOWN: ICU 2.0

EXTENDED_YEAR

public static final int EXTENDED_YEAR
Field number for get() and set() indicating the extended year. This is a single number designating the year of this calendar system, encompassing all supra-year fields. For example, for the Julian calendar system, year numbers are positive, with an era of BCE or CE. An extended year value for the Julian calendar system assigns positive values to CE years and negative values to BCE years, with 1 BCE being year 0.

UNKNOWN: ICU 2.0

FEBRUARY

public static final int FEBRUARY
Value of the MONTH field indicating the second month of the year.

UNKNOWN: ICU 2.0

FRIDAY

public static final int FRIDAY
Value of the DAY_OF_WEEK field indicating Friday.

UNKNOWN: ICU 2.0

GREATEST_MINIMUM

protected static final int GREATEST_MINIMUM
Limit type for getLimit() and handleGetLimit() indicating the greatest minimum value that a field can take.

See Also: Calendar Calendar

UNKNOWN: ICU 2.0

HOUR

public static final int HOUR
Field number for get and set indicating the hour of the morning or afternoon. HOUR is used for the 12-hour clock. E.g., at 10:04:15.250 PM the HOUR is 10.

See Also: AM_PM HOUR_OF_DAY

UNKNOWN: ICU 2.0

HOUR_OF_DAY

public static final int HOUR_OF_DAY
Field number for get and set indicating the hour of the day. HOUR_OF_DAY is used for the 24-hour clock. E.g., at 10:04:15.250 PM the HOUR_OF_DAY is 22.

See Also: HOUR

UNKNOWN: ICU 2.0

INTERNALLY_SET

protected static final int INTERNALLY_SET
Value of the time stamp stamp[] indicating that a field has been set via computations from the time or from other fields.

See Also: UNSET MINIMUM_USER_STAMP

UNKNOWN: ICU 2.0

JANUARY

public static final int JANUARY
Value of the MONTH field indicating the first month of the year.

UNKNOWN: ICU 2.0

JAN_1_1_JULIAN_DAY

protected static final int JAN_1_1_JULIAN_DAY
The Julian day of the Gregorian epoch, that is, January 1, 1 on the Gregorian calendar.

UNKNOWN: ICU 2.0

JULIAN_DAY

public static final int JULIAN_DAY
Field number for get() and set() indicating the modified Julian day number. This is different from the conventional Julian day number in two regards. First, it demarcates days at local zone midnight, rather than noon GMT. Second, it is a local number; that is, it depends on the local time zone. It can be thought of as a single number that encompasses all the date-related fields.

UNKNOWN: ICU 2.0

JULY

public static final int JULY
Value of the MONTH field indicating the seventh month of the year.

UNKNOWN: ICU 2.0

JUNE

public static final int JUNE
Value of the MONTH field indicating the sixth month of the year.

UNKNOWN: ICU 2.0

LEAST_MAXIMUM

protected static final int LEAST_MAXIMUM
Limit type for getLimit() and handleGetLimit() indicating the least maximum value that a field can take.

See Also: Calendar Calendar

UNKNOWN: ICU 2.0

MARCH

public static final int MARCH
Value of the MONTH field indicating the third month of the year.

UNKNOWN: ICU 2.0

MAXIMUM

protected static final int MAXIMUM
Limit type for getLimit() and handleGetLimit() indicating the maximum value that a field can take (greatest maximum).

See Also: Calendar Calendar

UNKNOWN: ICU 2.0

MAX_DATE

protected static final Date MAX_DATE
The maximum supported Date. This value is equivalent to MAX_JULIAN and MAX_MILLIS.

UNKNOWN: ICU 2.0

MAX_FIELD_COUNT

protected static final int MAX_FIELD_COUNT
The maximum number of fields possible. Subclasses must not define more total fields than this number.

UNKNOWN: ICU 2.0

MAX_JULIAN

protected static final int MAX_JULIAN
The maximum supported Julian day. This value is equivalent to MAX_MILLIS and MAX_DATE.

See Also: JULIAN_DAY

UNKNOWN: ICU 2.0

MAX_MILLIS

protected static final long MAX_MILLIS
The maximum supported epoch milliseconds. This value is equivalent to MAX_JULIAN and MAX_DATE.

UNKNOWN: ICU 2.0

MAY

public static final int MAY
Value of the MONTH field indicating the fifth month of the year.

UNKNOWN: ICU 2.0

MILLISECOND

public static final int MILLISECOND
Field number for get and set indicating the millisecond within the second. E.g., at 10:04:15.250 PM the MILLISECOND is 250.

UNKNOWN: ICU 2.0

MILLISECONDS_IN_DAY

public static final int MILLISECONDS_IN_DAY
Field number for get() and set() indicating the milliseconds in the day. This ranges from 0 to 23:59:59.999 (regardless of DST). This field behaves exactly like a composite of all time-related fields, not including the zone fields. As such, it also reflects discontinuities of those fields on DST transition days. On a day of DST onset, it will jump forward. On a day of DST cessation, it will jump backward. This reflects the fact that is must be combined with the DST_OFFSET field to obtain a unique local time value.

UNKNOWN: ICU 2.0

MINIMUM

protected static final int MINIMUM
Limit type for getLimit() and handleGetLimit() indicating the minimum value that a field can take (least minimum).

See Also: Calendar Calendar

UNKNOWN: ICU 2.0

MINIMUM_USER_STAMP

protected static final int MINIMUM_USER_STAMP
If the time stamp stamp[] has a value greater than or equal to MINIMUM_USER_SET then it has been set by the user via a call to set().

See Also: UNSET INTERNALLY_SET

UNKNOWN: ICU 2.0

MINUTE

public static final int MINUTE
Field number for get and set indicating the minute within the hour. E.g., at 10:04:15.250 PM the MINUTE is 4.

UNKNOWN: ICU 2.0

MIN_DATE

protected static final Date MIN_DATE
The minimum supported Date. This value is equivalent to MIN_JULIAN and MIN_MILLIS.

UNKNOWN: ICU 2.0

MIN_JULIAN

protected static final int MIN_JULIAN
The minimum supported Julian day. This value is equivalent to MIN_MILLIS and MIN_DATE.

See Also: JULIAN_DAY

UNKNOWN: ICU 2.0

MIN_MILLIS

protected static final long MIN_MILLIS
The minimum supported epoch milliseconds. This value is equivalent to MIN_JULIAN and MIN_DATE.

UNKNOWN: ICU 2.0

MONDAY

public static final int MONDAY
Value of the DAY_OF_WEEK field indicating Monday.

UNKNOWN: ICU 2.0

MONTH

public static final int MONTH
Field number for get and set indicating the month. This is a calendar-specific value. The first month of the year is JANUARY; the last depends on the number of months in a year.

See Also: JANUARY FEBRUARY MARCH APRIL MAY JUNE JULY AUGUST SEPTEMBER OCTOBER NOVEMBER DECEMBER UNDECIMBER

UNKNOWN: ICU 2.0

NOVEMBER

public static final int NOVEMBER
Value of the MONTH field indicating the eleventh month of the year.

UNKNOWN: ICU 2.0

OCTOBER

public static final int OCTOBER
Value of the MONTH field indicating the tenth month of the year.

UNKNOWN: ICU 2.0

ONE_DAY

protected static final long ONE_DAY
The number of milliseconds in one day. Although ONE_DAY and ONE_WEEK can fit into ints, they must be longs in order to prevent arithmetic overflow when performing (bug 4173516).

UNKNOWN: ICU 2.0

ONE_HOUR

protected static final int ONE_HOUR
The number of milliseconds in one hour.

UNKNOWN: ICU 2.0

ONE_MINUTE

protected static final int ONE_MINUTE
The number of milliseconds in one minute.

UNKNOWN: ICU 2.0

ONE_SECOND

protected static final int ONE_SECOND
The number of milliseconds in one second.

UNKNOWN: ICU 2.0

ONE_WEEK

protected static final long ONE_WEEK
The number of milliseconds in one week. Although ONE_DAY and ONE_WEEK can fit into ints, they must be longs in order to prevent arithmetic overflow when performing (bug 4173516).

UNKNOWN: ICU 2.0

PM

public static final int PM
Value of the AM_PM field indicating the period of the day from noon to just before midnight.

UNKNOWN: ICU 2.0

RESOLVE_REMAP

protected static final int RESOLVE_REMAP
Value to OR against resolve table field values for remapping.

See Also: Calendar

UNKNOWN: ICU 2.0

SATURDAY

public static final int SATURDAY
Value of the DAY_OF_WEEK field indicating Saturday.

UNKNOWN: ICU 2.0

SECOND

public static final int SECOND
Field number for get and set indicating the second within the minute. E.g., at 10:04:15.250 PM the SECOND is 15.

UNKNOWN: ICU 2.0

SEPTEMBER

public static final int SEPTEMBER
Value of the MONTH field indicating the ninth month of the year.

UNKNOWN: ICU 2.0

SUNDAY

public static final int SUNDAY
Value of the DAY_OF_WEEK field indicating Sunday.

UNKNOWN: ICU 2.0

THURSDAY

public static final int THURSDAY
Value of the DAY_OF_WEEK field indicating Thursday.

UNKNOWN: ICU 2.0

TUESDAY

public static final int TUESDAY
Value of the DAY_OF_WEEK field indicating Tuesday.

UNKNOWN: ICU 2.0

UNDECIMBER

public static final int UNDECIMBER
Value of the MONTH field indicating the thirteenth month of the year. Although GregorianCalendar does not use this value, lunar calendars do.

UNKNOWN: ICU 2.0

UNSET

protected static final int UNSET
Value of the time stamp stamp[] indicating that a field has not been set since the last call to clear().

See Also: INTERNALLY_SET MINIMUM_USER_STAMP

UNKNOWN: ICU 2.0

WEDNESDAY

public static final int WEDNESDAY
Value of the DAY_OF_WEEK field indicating Wednesday.

UNKNOWN: ICU 2.0

WEEKDAY

public static final int WEEKDAY
Value returned by getDayOfWeekType(int dayOfWeek) to indicate a weekday.

See Also: WEEKEND WEEKEND_ONSET WEEKEND_CEASE Calendar

UNKNOWN: ICU 2.0

WEEKEND

public static final int WEEKEND
Value returned by getDayOfWeekType(int dayOfWeek) to indicate a weekend day.

See Also: WEEKDAY WEEKEND_ONSET WEEKEND_CEASE Calendar

UNKNOWN: ICU 2.0

WEEKEND_CEASE

public static final int WEEKEND_CEASE
Value returned by getDayOfWeekType(int dayOfWeek) to indicate a day that starts as the weekend and transitions to a weekday. Call getWeekendTransition() to get the point of transition.

See Also: WEEKDAY WEEKEND WEEKEND_ONSET Calendar

UNKNOWN: ICU 2.0

WEEKEND_ONSET

public static final int WEEKEND_ONSET
Value returned by getDayOfWeekType(int dayOfWeek) to indicate a day that starts as a weekday and transitions to the weekend. Call getWeekendTransition() to get the point of transition.

See Also: WEEKDAY WEEKEND WEEKEND_CEASE Calendar

UNKNOWN: ICU 2.0

WEEK_OF_MONTH

public static final int WEEK_OF_MONTH
Field number for get and set indicating the week number within the current month. The first week of the month, as defined by getFirstDayOfWeek() and getMinimalDaysInFirstWeek(), has value 1. Subclasses define the value of WEEK_OF_MONTH for days before the first week of the month.

See Also: Calendar Calendar

UNKNOWN: ICU 2.0

WEEK_OF_YEAR

public static final int WEEK_OF_YEAR
Field number for get and set indicating the week number within the current year. The first week of the year, as defined by getFirstDayOfWeek() and getMinimalDaysInFirstWeek(), has value 1. Subclasses define the value of WEEK_OF_YEAR for days before the first week of the year.

See Also: Calendar Calendar

UNKNOWN: ICU 2.0

YEAR

public static final int YEAR
Field number for get and set indicating the year. This is a calendar-specific value; see subclass documentation.

UNKNOWN: ICU 2.0

YEAR_WOY

public static final int YEAR_WOY
Field number for get() and set() indicating the extended year corresponding to the WEEK_OF_YEAR field. This may be one greater or less than the value of EXTENDED_YEAR.

UNKNOWN: ICU 2.0

ZONE_OFFSET

public static final int ZONE_OFFSET
Field number for get and set indicating the raw offset from GMT in milliseconds.

UNKNOWN: ICU 2.0

Constructor Detail

Calendar

protected Calendar()
Constructs a Calendar with the default time zone and locale.

See Also: TimeZone

UNKNOWN: ICU 2.0

Calendar

protected Calendar(TimeZone zone, Locale aLocale)
Constructs a calendar with the specified time zone and locale.

Parameters: zone the time zone to use aLocale the locale for the week data

UNKNOWN: ICU 2.0

Calendar

protected Calendar(TimeZone zone, ULocale locale)
Constructs a calendar with the specified time zone and locale.

Parameters: zone the time zone to use locale the ulocale for the week data

UNKNOWN: ICU 3.2 This API might change or be removed in a future release.

Method Detail

add

public void add(int field, int amount)
Add a signed amount to a specified field, using this calendar's rules. For example, to add three days to the current date, you can call add(Calendar.DATE, 3).

When adding to certain fields, the values of other fields may conflict and need to be changed. For example, when adding one to the {@link #MONTH MONTH} field for the Gregorian date 1/31/96, the {@link #DAY_OF_MONTH DAY_OF_MONTH} field must be adjusted so that the result is 2/29/96 rather than the invalid 2/31/96.

The com.ibm.icu.util.Calendar implementation of this method is able to add to all fields except for {@link #ERA ERA}, {@link #DST_OFFSET DST_OFFSET}, and {@link #ZONE_OFFSET ZONE_OFFSET}. Subclasses may, of course, add support for additional fields in their overrides of add.

Note: You should always use roll and add rather than attempting to perform arithmetic operations directly on the fields of a Calendar. It is quite possible for Calendar subclasses to have fields with non-linear behavior, for example missing months or days during non-leap years. The subclasses' add and roll methods will take this into account, while simple arithmetic manipulations may give invalid results.

Subclassing:
This implementation of add assumes that the behavior of the field is continuous between its minimum and maximum, which are found by calling {@link #getActualMinimum getActualMinimum} and {@link #getActualMaximum getActualMaximum}. For such fields, simple arithmetic operations are sufficient to perform the add.

Subclasses that have fields for which this assumption of continuity breaks down must overide add to handle those fields specially. For example, in the Hebrew calendar the month "Adar I" only occurs in leap years; in other years the calendar jumps from Shevat (month #4) to Adar (month #6). The {@link HebrewCalendar#add HebrewCalendar.add} method takes this into account, so that adding one month to a date in Shevat gives the proper result (Adar) in a non-leap year.

Parameters: field the time field. amount the amount to add to the field.

Throws: IllegalArgumentException if the field is invalid or refers to a field that cannot be handled by this method.

See Also: Calendar

UNKNOWN: ICU 2.0

after

public boolean after(Object when)
Compares the time field records. Equivalent to comparing result of conversion to UTC.

Parameters: when the Calendar to be compared with this Calendar.

Returns: true if the current time of this Calendar is after the time of Calendar when; false otherwise.

UNKNOWN: ICU 2.0

before

public boolean before(Object when)
Compares the time field records. Equivalent to comparing result of conversion to UTC.

Parameters: when the Calendar to be compared with this Calendar.

Returns: true if the current time of this Calendar is before the time of Calendar when; false otherwise.

UNKNOWN: ICU 2.0

clear

public final void clear()
Clears the values of all the time fields.

UNKNOWN: ICU 2.0

clear

public final void clear(int field)
Clears the value in the given time field.

Parameters: field the time field to be cleared.

UNKNOWN: ICU 2.0

clone

public Object clone()
Overrides Cloneable

UNKNOWN: ICU 2.0

compareTo

public int compareTo(Calendar that)
Compares the times (in millis) represented by two Calendar objects.

Parameters: that the Calendar to compare to this.

Returns: 0 if the time represented by this Calendar is equal to the time represented by that Calendar, a value less than 0 if the time represented by this is before the time represented by that, and a value greater than 0 if the time represented by this is after the time represented by that.

Throws: NullPointerException if that Calendar is null. IllegalArgumentException if the time of that Calendar can't be obtained because of invalid calendar values.

UNKNOWN: ICU 3.4 This API might change or be removed in a future release.

compareTo

public int compareTo(Object that)
Implement comparable API as a convenience override of {@link #compareTo(Calendar)}.

UNKNOWN: ICU 3.4 This API might change or be removed in a future release.

complete

protected void complete()
Fills in any unset fields in the time field list.

UNKNOWN: ICU 2.0

computeFields

protected void computeFields()
Converts the current millisecond time value time to field values in fields[]. This synchronizes the time field values with a new time that is set for the calendar. The time is not recomputed first; to recompute the time, then the fields, call the complete method.

See Also: Calendar

UNKNOWN: ICU 2.0

computeGregorianFields

protected final void computeGregorianFields(int julianDay)
Compute the Gregorian calendar year, month, and day of month from the Julian day. These values are not stored in fields, but in member variables gregorianXxx. They are used for time zone computations and by subclasses that are Gregorian derivatives. Subclasses may call this method to perform a Gregorian calendar millis->fields computation. To perform a Gregorian calendar fields->millis computation, call computeGregorianMonthStart().

See Also: Calendar

UNKNOWN: ICU 2.0

computeGregorianMonthStart

protected int computeGregorianMonthStart(int year, int month)
Compute the Julian day of a month of the Gregorian calendar. Subclasses may call this method to perform a Gregorian calendar fields->millis computation. To perform a Gregorian calendar millis->fields computation, call computeGregorianFields().

Parameters: year extended Gregorian year month zero-based Gregorian month

Returns: the Julian day number of the day before the first day of the given month in the given extended year

See Also: Calendar

UNKNOWN: ICU 2.0

computeJulianDay

protected int computeJulianDay()
Compute the Julian day number as specified by this calendar's fields.

UNKNOWN: ICU 2.0

computeMillisInDay

protected int computeMillisInDay()
Compute the milliseconds in the day from the fields. This is a value from 0 to 23:59:59.999 inclusive, unless fields are out of range, in which case it can be an arbitrary value. This value reflects local zone wall time.

UNKNOWN: ICU 2.0

computeTime

protected void computeTime()
Converts the current field values in fields[] to the millisecond time value time.

UNKNOWN: ICU 2.0

computeZoneOffset

protected int computeZoneOffset(long millis, int millisInDay)
This method can assume EXTENDED_YEAR has been set.

Parameters: millis milliseconds of the date fields (local midnight millis) millisInDay milliseconds of the time fields; may be out or range.

Returns: total zone offset (raw + DST) for the given moment

UNKNOWN: ICU 2.0

equals

public boolean equals(Object obj)
Compares this calendar to the specified object. The result is true if and only if the argument is not null and is a Calendar object that represents the same calendar as this object.

Parameters: obj the object to compare with.

Returns: true if the objects are the same; false otherwise.

UNKNOWN: ICU 2.0

fieldDifference

public int fieldDifference(Date when, int field)
[NEW] Return the difference between the given time and the time this calendar object is set to. If this calendar is set before the given time, the returned value will be positive. If this calendar is set after the given time, the returned value will be negative. The field parameter specifies the units of the return value. For example, if fieldDifference(when, Calendar.MONTH) returns 3, then this calendar is set to 3 months before when, and possibly some additional time less than one month.

As a side effect of this call, this calendar is advanced toward when by the given amount. That is, calling this method has the side effect of calling add(field, n), where n is the return value.

Usage: To use this method, call it first with the largest field of interest, then with progressively smaller fields. For example:

 int y = cal.fieldDifference(when, Calendar.YEAR);
 int m = cal.fieldDifference(when, Calendar.MONTH);
 int d = cal.fieldDifference(when, Calendar.DATE);
computes the difference between cal and when in years, months, and days.

Note: fieldDifference() is asymmetrical. That is, in the following code:

 cal.setTime(date1);
 int m1 = cal.fieldDifference(date2, Calendar.MONTH);
 int d1 = cal.fieldDifference(date2, Calendar.DATE);
 cal.setTime(date2);
 int m2 = cal.fieldDifference(date1, Calendar.MONTH);
 int d2 = cal.fieldDifference(date1, Calendar.DATE);
one might expect that m1 == -m2 && d1 == -d2. However, this is not generally the case, because of irregularities in the underlying calendar system (e.g., the Gregorian calendar has a varying number of days per month).

Parameters: when the date to compare this calendar's time to field the field in which to compute the result

Returns: the difference, either positive or negative, between this calendar's time and when, in terms of field.

UNKNOWN: ICU 2.0

fieldName

protected String fieldName(int field)
Return a string name for a field, for debugging and exceptions.

UNKNOWN: ICU 2.0

floorDivide

protected static final long floorDivide(long numerator, long denominator)
Divide two long integers, returning the floor of the quotient.

Unlike the built-in division, this is mathematically well-behaved. E.g., -1/4 => 0 but floorDivide(-1,4) => -1.

Parameters: numerator the numerator denominator a divisor which must be > 0

Returns: the floor of the quotient.

UNKNOWN: ICU 2.0

floorDivide

protected static final int floorDivide(int numerator, int denominator)
Divide two integers, returning the floor of the quotient.

Unlike the built-in division, this is mathematically well-behaved. E.g., -1/4 => 0 but floorDivide(-1,4) => -1.

Parameters: numerator the numerator denominator a divisor which must be > 0

Returns: the floor of the quotient.

UNKNOWN: ICU 2.0

floorDivide

protected static final int floorDivide(int numerator, int denominator, int[] remainder)
Divide two integers, returning the floor of the quotient, and the modulus remainder.

Unlike the built-in division, this is mathematically well-behaved. E.g., -1/4 => 0 and -1%4 => -1, but floorDivide(-1,4) => -1 with remainder[0] => 3.

Parameters: numerator the numerator denominator a divisor which must be > 0 remainder an array of at least one element in which the value numerator mod denominator is returned. Unlike numerator % denominator, this will always be non-negative.

Returns: the floor of the quotient.

UNKNOWN: ICU 2.0

floorDivide

protected static final int floorDivide(long numerator, int denominator, int[] remainder)
Divide two integers, returning the floor of the quotient, and the modulus remainder.

Unlike the built-in division, this is mathematically well-behaved. E.g., -1/4 => 0 and -1%4 => -1, but floorDivide(-1,4) => -1 with remainder[0] => 3.

Parameters: numerator the numerator denominator a divisor which must be > 0 remainder an array of at least one element in which the value numerator mod denominator is returned. Unlike numerator % denominator, this will always be non-negative.

Returns: the floor of the quotient.

UNKNOWN: ICU 2.0

get

public final int get(int field)
Gets the value for a given time field.

Parameters: field the given time field.

Returns: the value for the given time field.

UNKNOWN: ICU 2.0

getActualMaximum

public int getActualMaximum(int field)
Return the maximum value that this field could have, given the current date. For example, with the Gregorian date February 3, 1997 and the {@link #DAY_OF_MONTH DAY_OF_MONTH} field, the actual maximum is 28; for February 3, 1996 it is 29.

The actual maximum computation ignores smaller fields and the current value of like-sized fields. For example, the actual maximum of the DAY_OF_YEAR or MONTH depends only on the year and supra-year fields. The actual maximum of the DAY_OF_MONTH depends, in addition, on the MONTH field and any other fields at that granularity (such as ChineseCalendar.IS_LEAP_MONTH). The DAY_OF_WEEK_IN_MONTH field does not depend on the current DAY_OF_WEEK; it returns the maximum for any day of week in the current month. Likewise for the WEEK_OF_MONTH and WEEK_OF_YEAR fields.

Parameters: field the field whose maximum is desired

Returns: the maximum of the given field for the current date of this calendar

See Also: Calendar Calendar

UNKNOWN: ICU 2.0

getActualMinimum

public int getActualMinimum(int field)
Return the minimum value that this field could have, given the current date. For most fields, this is the same as {@link #getMinimum getMinimum} and {@link #getGreatestMinimum getGreatestMinimum}. However, some fields, especially those related to week number, are more complicated.

For example, assume {@link #getMinimalDaysInFirstWeek getMinimalDaysInFirstWeek} returns 4 and {@link #getFirstDayOfWeek getFirstDayOfWeek} returns SUNDAY. If the first day of the month is Sunday, Monday, Tuesday, or Wednesday there will be four or more days in the first week, so it will be week number 1, and getActualMinimum(WEEK_OF_MONTH) will return 1. However, if the first of the month is a Thursday, Friday, or Saturday, there are not four days in that week, so it is week number 0, and getActualMinimum(WEEK_OF_MONTH) will return 0.

Parameters: field the field whose actual minimum value is desired.

Returns: the minimum of the given field for the current date of this calendar

See Also: Calendar Calendar

UNKNOWN: ICU 2.0

getAvailableLocales

public static Locale[] getAvailableLocales()
Gets the list of locales for which Calendars are installed.

Returns: the list of locales for which Calendars are installed.

UNKNOWN: ICU 2.0

getAvailableULocales

public static ULocale[] getAvailableULocales()
Gets the list of locales for which Calendars are installed.

Returns: the list of locales for which Calendars are installed.

UNKNOWN: ICU 3.2 This API might change or be removed in a future release.

getDateTimeFormat

public DateFormat getDateTimeFormat(int dateStyle, int timeStyle, Locale loc)
Return a DateFormat appropriate to this calendar. Subclasses wishing to specialize this behavior should override handleGetDateFormat()

See Also: Calendar

UNKNOWN: ICU 2.0

getDateTimeFormat

public DateFormat getDateTimeFormat(int dateStyle, int timeStyle, ULocale loc)
Return a DateFormat appropriate to this calendar. Subclasses wishing to specialize this behavior should override handleGetDateFormat()

See Also: Calendar

UNKNOWN: ICU 3.2 This API might change or be removed in a future release.

getDayOfWeekType

public int getDayOfWeekType(int dayOfWeek)
Return whether the given day of the week is a weekday, a weekend day, or a day that transitions from one to the other, in this calendar system. If a transition occurs at midnight, then the days before and after the transition will have the type WEEKDAY or WEEKEND. If a transition occurs at a time other than midnight, then the day of the transition will have the type WEEKEND_ONSET or WEEKEND_CEASE. In this case, the method getWeekendTransition() will return the point of transition.

Parameters: dayOfWeek either SUNDAY, MONDAY, TUESDAY, WEDNESDAY, THURSDAY, FRIDAY, or SATURDAY

Returns: either WEEKDAY, WEEKEND, WEEKEND_ONSET, or WEEKEND_CEASE

Throws: IllegalArgumentException if dayOfWeek is not between SUNDAY and SATURDAY, inclusive

See Also: WEEKDAY WEEKEND WEEKEND_ONSET WEEKEND_CEASE Calendar isWeekend isWeekend

UNKNOWN: ICU 2.0

getDisplayName

public String getDisplayName(Locale loc)
Return the name of this calendar in the language of the given locale.

UNKNOWN: ICU 2.0

getDisplayName

public String getDisplayName(ULocale loc)
Return the name of this calendar in the language of the given locale.

UNKNOWN: ICU 3.2 This API might change or be removed in a future release.

getFieldCount

public final int getFieldCount()
Return the number of fields defined by this calendar. Valid field arguments to set() and get() are 0..getFieldCount()-1.

UNKNOWN: ICU 2.0

getFieldResolutionTable

protected int[][][] getFieldResolutionTable()
Return the field resolution array for this calendar. Calendars that define additional fields or change the semantics of existing fields should override this method to adjust the field resolution semantics accordingly. Other subclasses should not override this method.

See Also: Calendar

UNKNOWN: ICU 2.0

getFirstDayOfWeek

public int getFirstDayOfWeek()
Gets what the first day of the week is; e.g., Sunday in US, Monday in France.

Returns: the first day of the week.

UNKNOWN: ICU 2.0

getGreatestMinimum

public final int getGreatestMinimum(int field)
Gets the highest minimum value for the given field if varies. Otherwise same as getMinimum(). For Gregorian, no difference.

Parameters: field the given time field.

Returns: the highest minimum value for the given time field.

UNKNOWN: ICU 2.0

getGregorianDayOfMonth

protected final int getGregorianDayOfMonth()
Return the day of month (1-based) on the Gregorian calendar as computed by computeGregorianFields().

See Also: Calendar

UNKNOWN: ICU 2.0

getGregorianDayOfYear

protected final int getGregorianDayOfYear()
Return the day of year (1-based) on the Gregorian calendar as computed by computeGregorianFields().

See Also: Calendar

UNKNOWN: ICU 2.0

getGregorianMonth

protected final int getGregorianMonth()
Return the month (0-based) on the Gregorian calendar as computed by computeGregorianFields().

See Also: Calendar

UNKNOWN: ICU 2.0

getGregorianYear

protected final int getGregorianYear()
Return the extended year on the Gregorian calendar as computed by computeGregorianFields().

See Also: Calendar

UNKNOWN: ICU 2.0

getInstance

public static Calendar getInstance()
Gets a calendar using the default time zone and locale.

Returns: a Calendar.

UNKNOWN: ICU 2.0

getInstance

public static Calendar getInstance(TimeZone zone)
Gets a calendar using the specified time zone and default locale.

Parameters: zone the time zone to use

Returns: a Calendar.

UNKNOWN: ICU 2.0

getInstance

public static Calendar getInstance(Locale aLocale)
Gets a calendar using the default time zone and specified locale.

Parameters: aLocale the locale for the week data

Returns: a Calendar.

UNKNOWN: ICU 2.0

getInstance

public static Calendar getInstance(ULocale locale)
Gets a calendar using the default time zone and specified locale.

Parameters: locale the ulocale for the week data

Returns: a Calendar.

UNKNOWN: ICU 3.2 This API might change or be removed in a future release.

getInstance

public static Calendar getInstance(TimeZone zone, Locale aLocale)
Gets a calendar with the specified time zone and locale.

Parameters: zone the time zone to use aLocale the locale for the week data

Returns: a Calendar.

UNKNOWN: ICU 2.0

getInstance

public static Calendar getInstance(TimeZone zone, ULocale locale)
Gets a calendar with the specified time zone and locale.

Parameters: zone the time zone to use locale the ulocale for the week data

Returns: a Calendar.

UNKNOWN: ICU 3.2 This API might change or be removed in a future release.

getLeastMaximum

public final int getLeastMaximum(int field)
Gets the lowest maximum value for the given field if varies. Otherwise same as getMaximum(). e.g., for Gregorian DAY_OF_MONTH, 28.

Parameters: field the given time field.

Returns: the lowest maximum value for the given time field.

UNKNOWN: ICU 2.0

getLimit

protected int getLimit(int field, int limitType)
Return a limit for a field.

Parameters: field the field, from 0..getFieldCount()-1 limitType the type specifier for the limit

See Also: MINIMUM GREATEST_MINIMUM LEAST_MAXIMUM MAXIMUM

UNKNOWN: ICU 2.0

getLocale

public final ULocale getLocale(ULocale.Type type)
Return the locale that was used to create this object, or null. This may may differ from the locale requested at the time of this object's creation. For example, if an object is created for locale en_US_CALIFORNIA, the actual data may be drawn from en (the actual locale), and en_US may be the most specific locale that exists (the valid locale).

Note: This method will be implemented in ICU 3.0; ICU 2.8 contains a partial preview implementation. The * actual locale is returned correctly, but the valid locale is not, in most cases.

Parameters: type type of information requested, either {@link com.ibm.icu.util.ULocale#VALID_LOCALE} or {@link com.ibm.icu.util.ULocale#ACTUAL_LOCALE}.

Returns: the information specified by type, or null if this object was not constructed from locale data.

See Also: ULocale VALID_LOCALE ACTUAL_LOCALE

UNKNOWN: ICU 2.8 (retain) This API might change or be removed in a future release.

getMaximum

public final int getMaximum(int field)
Gets the maximum value for the given time field. e.g. for Gregorian DAY_OF_MONTH, 31.

Parameters: field the given time field.

Returns: the maximum value for the given time field.

UNKNOWN: ICU 2.0

getMinimalDaysInFirstWeek

public int getMinimalDaysInFirstWeek()
Gets what the minimal days required in the first week of the year are; e.g., if the first week is defined as one that contains the first day of the first month of a year, getMinimalDaysInFirstWeek returns 1. If the minimal days required must be a full week, getMinimalDaysInFirstWeek returns 7.

Returns: the minimal days required in the first week of the year.

UNKNOWN: ICU 2.0

getMinimum

public final int getMinimum(int field)
Gets the minimum value for the given time field. e.g., for Gregorian DAY_OF_MONTH, 1.

Parameters: field the given time field.

Returns: the minimum value for the given time field.

UNKNOWN: ICU 2.0

getStamp

protected final int getStamp(int field)
Return the timestamp of a field.

UNKNOWN: ICU 2.0

getTime

public final Date getTime()
Gets this Calendar's current time.

Returns: the current time.

UNKNOWN: ICU 2.0

getTimeInMillis

public long getTimeInMillis()
Gets this Calendar's current time as a long.

Returns: the current time as UTC milliseconds from the epoch.

UNKNOWN: ICU 2.0

getTimeZone

public TimeZone getTimeZone()
Gets the time zone.

Returns: the time zone object associated with this calendar.

UNKNOWN: ICU 2.0

getType

public String getType()
Return the current Calendar type. Note, in 3.0 this function will return 'gregorian' in Calendar to emulate legacy behavior

Returns: type of calendar (gregorian, etc)

UNKNOWN: ICU 3.0

getWeekendTransition

public int getWeekendTransition(int dayOfWeek)
Return the time during the day at which the weekend begins or end in this calendar system. If getDayOfWeekType(dayOfWeek) == WEEKEND_ONSET return the time at which the weekend begins. If getDayOfWeekType(dayOfWeek) == WEEKEND_CEASE return the time at which the weekend ends. If getDayOfWeekType(dayOfWeek) has some other value, then throw an exception.

Parameters: dayOfWeek either SUNDAY, MONDAY, TUESDAY, WEDNESDAY, THURSDAY, FRIDAY, or SATURDAY

Returns: the milliseconds after midnight at which the weekend begins or ends

Throws: IllegalArgumentException if dayOfWeek is not WEEKEND_ONSET or WEEKEND_CEASE

See Also: Calendar isWeekend isWeekend

UNKNOWN: ICU 2.0

gregorianMonthLength

protected static final int gregorianMonthLength(int y, int m)
Return the length of a month of the Gregorian calendar.

Parameters: y the extended year m the 0-based month number

Returns: the number of days in the given month

UNKNOWN: ICU 2.0

gregorianPreviousMonthLength

protected static final int gregorianPreviousMonthLength(int y, int m)
Return the length of a previous month of the Gregorian calendar.

Parameters: y the extended year m the 0-based month number

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

UNKNOWN: ICU 2.0

handleComputeFields

protected void handleComputeFields(int julianDay)
Subclasses may override this method to compute several fields specific to each calendar system. These are: Subclasses can refer to the DAY_OF_WEEK and DOW_LOCAL fields, which will be set when this method is called. Subclasses can also call the getGregorianXxx() methods to obtain Gregorian calendar equivalents for the given Julian day.

In addition, subclasses should compute any subclass-specific fields, that is, fields from BASE_FIELD_COUNT to getFieldCount() - 1.

The default implementation in Calendar implements a pure proleptic Gregorian calendar.

UNKNOWN: ICU 2.0

handleComputeJulianDay

protected int handleComputeJulianDay(int bestField)
Subclasses may override this. This method calls handleGetMonthLength() to obtain the calendar-specific month length.

UNKNOWN: ICU 2.0

handleComputeMonthStart

protected abstract int handleComputeMonthStart(int eyear, int month, boolean useMonth)
Return the Julian day number of day before the first day of the given month in the given extended year. Subclasses should override this method to implement their calendar system.

Parameters: eyear the extended year month the zero-based month, or 0 if useMonth is false useMonth if false, compute the day before the first day of the given year, otherwise, compute the day before the first day of the given month

Returns: the Julian day number of the day before the first day of the given month and year

UNKNOWN: ICU 2.0

handleCreateFields

protected int[] handleCreateFields()
Subclasses that use additional fields beyond those defined in Calendar should override this method to return an int[] array of the appropriate length. The length must be at least BASE_FIELD_COUNT and no more than MAX_FIELD_COUNT.

UNKNOWN: ICU 2.0

handleGetDateFormat

protected DateFormat handleGetDateFormat(String pattern, Locale locale)
Create a DateFormat appropriate to this calendar. This is a framework method for subclasses to override. This method is responsible for creating the calendar-specific DateFormat and DateFormatSymbols objects as needed.

Parameters: pattern the pattern, specific to the DateFormat subclass locale the locale for which the symbols should be drawn

Returns: a DateFormat appropriate to this calendar

UNKNOWN: ICU 2.0

handleGetDateFormat

protected DateFormat handleGetDateFormat(String pattern, ULocale locale)
Create a DateFormat appropriate to this calendar. This is a framework method for subclasses to override. This method is responsible for creating the calendar-specific DateFormat and DateFormatSymbols objects as needed.

Parameters: pattern the pattern, specific to the DateFormat subclass locale the locale for which the symbols should be drawn

Returns: a DateFormat appropriate to this calendar

UNKNOWN: ICU 3.2 This API might change or be removed in a future release.

handleGetExtendedYear

protected abstract int handleGetExtendedYear()
Return the extended year defined by the current fields. This will use the EXTENDED_YEAR field or the YEAR and supra-year fields (such as ERA) specific to the calendar system, depending on which set of fields is newer.

Returns: the extended year

UNKNOWN: ICU 2.0

handleGetLimit

protected abstract int handleGetLimit(int field, int limitType)
Subclass API for defining limits of different types. Subclasses must implement this method to return limits for the following fields:
ERA
 YEAR
 MONTH
 WEEK_OF_YEAR
 WEEK_OF_MONTH
 DAY_OF_MONTH
 DAY_OF_YEAR
 DAY_OF_WEEK_IN_MONTH
 YEAR_WOY
 EXTENDED_YEAR

Parameters: field one of the above field numbers limitType one of MINIMUM, GREATEST_MINIMUM, LEAST_MAXIMUM, or MAXIMUM

UNKNOWN: ICU 2.0

handleGetMonthLength

protected int handleGetMonthLength(int extendedYear, int month)
Return the number of days in the given month of the given extended year of this calendar system. Subclasses should override this method if they can provide a more correct or more efficient implementation than the default implementation in Calendar.

UNKNOWN: ICU 2.0

handleGetYearLength

protected int handleGetYearLength(int eyear)
Return the number of days in the given extended year of this calendar system. Subclasses should override this method if they can provide a more correct or more efficient implementation than the default implementation in Calendar.

UNKNOWN: ICU 2.0

hashCode

public int hashCode()
Returns a hash code for this calendar.

Returns: a hash code value for this object.

UNKNOWN: ICU 2.0

internalGet

protected final int internalGet(int field)
Gets the value for a given time field. This is an internal method for subclasses that does not trigger any calculations.

Parameters: field the given time field.

Returns: the value for the given time field.

UNKNOWN: ICU 2.0

internalGet

protected final int internalGet(int field, int defaultValue)
Get the value for a given time field, or return the given default value if the field is not set. This is an internal method for subclasses that does not trigger any calculations.

Parameters: field the given time field. defaultValue value to return if field is not set

Returns: the value for the given time field of defaultValue if the field is unset

UNKNOWN: ICU 2.0

internalGetTimeInMillis

protected final long internalGetTimeInMillis()
Return the current milliseconds without recomputing.

UNKNOWN: ICU 2.0

internalSet

protected final void internalSet(int field, int value)
Set a field to a value. Subclasses should use this method when computing fields. It sets the time stamp in the stamp[] array to INTERNALLY_SET. If a field that may not be set by subclasses is passed in, an IllegalArgumentException is thrown. This prevents subclasses from modifying fields that are intended to be calendar-system invariant.

UNKNOWN: ICU 2.0

isEquivalentTo

public boolean isEquivalentTo(Calendar other)
Returns true if the given Calendar object is equivalent to this one. An equivalent Calendar will behave exactly as this one does, but it may be set to a different time. By contrast, for the equals() method to return true, the other Calendar must be set to the same time.

Parameters: other the Calendar to be compared with this Calendar

UNKNOWN: ICU 2.4

isGregorianLeapYear

protected static final boolean isGregorianLeapYear(int year)
Determines if the given year is a leap year. Returns true if the given year is a leap year.

Parameters: year the given year.

Returns: true if the given year is a leap year; false otherwise.

UNKNOWN: ICU 2.0

isLenient

public boolean isLenient()
Tell whether date/time interpretation is to be lenient.

UNKNOWN: ICU 2.0

isSet

public final boolean isSet(int field)
Determines if the given time field has a value set.

Returns: true if the given time field has a value set; false otherwise.

UNKNOWN: ICU 2.0

isWeekend

public boolean isWeekend(Date date)
Return true if the given date and time is in the weekend in this calendar system. Equivalent to calling setTime() followed by isWeekend(). Note: This method changes the time this calendar is set to.

Parameters: date the date and time

Returns: true if the given date and time is part of the weekend

See Also: Calendar Calendar isWeekend

UNKNOWN: ICU 2.0

isWeekend

public boolean isWeekend()
Return true if this Calendar's current date and time is in the weekend in this calendar system.

Returns: true if the given date and time is part of the weekend

See Also: Calendar Calendar isWeekend

UNKNOWN: ICU 2.0

julianDayToDayOfWeek

protected static final int julianDayToDayOfWeek(int julian)
Return the day of week, from SUNDAY to SATURDAY, given a Julian day.

UNKNOWN: ICU 2.0

julianDayToMillis

protected static final long julianDayToMillis(int julian)
Converts Julian day to time as milliseconds.

Parameters: julian the given Julian day number.

Returns: time as milliseconds.

UNKNOWN: ICU 2.0

millisToJulianDay

protected static final int millisToJulianDay(long millis)
Converts time as milliseconds to Julian day.

Parameters: millis the given milliseconds.

Returns: the Julian day number.

UNKNOWN: ICU 2.0

newerField

protected int newerField(int defaultField, int alternateField)
Return the field that is newer, either defaultField, or alternateField. If neither is newer or neither is set, return defaultField.

UNKNOWN: ICU 2.0

newestStamp

protected int newestStamp(int first, int last, int bestStampSoFar)
Return the newest stamp of a given range of fields.

UNKNOWN: ICU 2.0

pinField

protected void pinField(int field)
Adjust the specified field so that it is within the allowable range for the date to which this calendar is set. For example, in a Gregorian calendar pinning the {@link #DAY_OF_MONTH DAY_OF_MONTH} field for a calendar set to April 31 would cause it to be set to April 30.

Subclassing:
This utility method is intended for use by subclasses that need to implement their own overrides of {@link #roll roll} and {@link #add add}.

Note: pinField is implemented in terms of {@link #getActualMinimum getActualMinimum} and {@link #getActualMaximum getActualMaximum}. If either of those methods uses a slow, iterative algorithm for a particular field, it would be unwise to attempt to call pinField for that field. If you really do need to do so, you should override this method to do something more efficient for that field.

Parameters: field The calendar field whose value should be pinned.

See Also: Calendar Calendar

UNKNOWN: ICU 2.0

prepareGetActual

protected void prepareGetActual(int field, boolean isMinimum)
Prepare this calendar for computing the actual minimum or maximum. This method modifies this calendar's fields; it is called on a temporary calendar.

Rationale: The semantics of getActualXxx() is to return the maximum or minimum value that the given field can take, taking into account other relevant fields. In general these other fields are larger fields. For example, when computing the actual maximum DAY_OF_MONTH, the current value of DAY_OF_MONTH itself is ignored, as is the value of any field smaller.

The time fields all have fixed minima and maxima, so we don't need to worry about them. This also lets us set the MILLISECONDS_IN_DAY to zero to erase any effects the time fields might have when computing date fields.

DAY_OF_WEEK is adjusted specially for the WEEK_OF_MONTH and WEEK_OF_YEAR fields to ensure that they are computed correctly.

UNKNOWN: ICU 2.0

resolveFields

protected int resolveFields(int[][][] precedenceTable)
Given a precedence table, return the newest field combination in the table, or -1 if none is found.

The precedence table is a 3-dimensional array of integers. It may be thought of as an array of groups. Each group is an array of lines. Each line is an array of field numbers. Within a line, if all fields are set, then the time stamp of the line is taken to be the stamp of the most recently set field. If any field of a line is unset, then the line fails to match. Within a group, the line with the newest time stamp is selected. The first field of the line is returned to indicate which line matched.

In some cases, it may be desirable to map a line to field that whose stamp is NOT examined. For example, if the best field is DAY_OF_WEEK then the DAY_OF_WEEK_IN_MONTH algorithm may be used. In order to do this, insert the value REMAP_RESOLVE | F at the start of the line, where F is the desired return field value. This field will NOT be examined; it only determines the return value if the other fields in the line are the newest.

If all lines of a group contain at least one unset field, then no line will match, and the group as a whole will fail to match. In that case, the next group will be processed. If all groups fail to match, then -1 is returned.

UNKNOWN: ICU 2.0

roll

public final void roll(int field, boolean up)
Rolls (up/down) a single unit of time on the given field. If the field is rolled past its maximum allowable value, it will "wrap" back to its minimum and continue rolling. For example, to roll the current date up by one day, you can call:

roll({@link #DATE}, true)

When rolling on the {@link #YEAR} field, it will roll the year value in the range between 1 and the value returned by calling {@link #getMaximum getMaximum}({@link #YEAR}).

When rolling on certain fields, the values of other fields may conflict and need to be changed. For example, when rolling the MONTH field for the Gregorian date 1/31/96 upward, the DAY_OF_MONTH field must be adjusted so that the result is 2/29/96 rather than the invalid 2/31/96.

Note: Calling roll(field, true) N times is not necessarily equivalent to calling roll(field, N). For example, imagine that you start with the date Gregorian date January 31, 1995. If you call roll(Calendar.MONTH, 2), the result will be March 31, 1995. But if you call roll(Calendar.MONTH, true), the result will be February 28, 1995. Calling it one more time will give March 28, 1995, which is usually not the desired result.

Note: You should always use roll and add rather than attempting to perform arithmetic operations directly on the fields of a Calendar. It is quite possible for Calendar subclasses to have fields with non-linear behavior, for example missing months or days during non-leap years. The subclasses' add and roll methods will take this into account, while simple arithmetic manipulations may give invalid results.

Parameters: field the calendar field to roll. up indicates if the value of the specified time field is to be rolled up or rolled down. Use true if rolling up, false otherwise.

Throws: IllegalArgumentException if the field is invalid or refers to a field that cannot be handled by this method.

See Also: Calendar Calendar

UNKNOWN: ICU 2.0

roll

public void roll(int field, int amount)
Rolls (up/down) a specified amount time on the given field. For example, to roll the current date up by three days, you can call roll(Calendar.DATE, 3). If the field is rolled past its maximum allowable value, it will "wrap" back to its minimum and continue rolling. For example, calling roll(Calendar.DATE, 10) on a Gregorian calendar set to 4/25/96 will result in the date 4/5/96.

When rolling on certain fields, the values of other fields may conflict and need to be changed. For example, when rolling the {@link #MONTH MONTH} field for the Gregorian date 1/31/96 by +1, the {@link #DAY_OF_MONTH DAY_OF_MONTH} field must be adjusted so that the result is 2/29/96 rather than the invalid 2/31/96.

The com.ibm.icu.util.Calendar implementation of this method is able to roll all fields except for {@link #ERA ERA}, {@link #DST_OFFSET DST_OFFSET}, and {@link #ZONE_OFFSET ZONE_OFFSET}. Subclasses may, of course, add support for additional fields in their overrides of roll.

Note: You should always use roll and add rather than attempting to perform arithmetic operations directly on the fields of a Calendar. It is quite possible for Calendar subclasses to have fields with non-linear behavior, for example missing months or days during non-leap years. The subclasses' add and roll methods will take this into account, while simple arithmetic manipulations may give invalid results.

Subclassing:
This implementation of roll assumes that the behavior of the field is continuous between its minimum and maximum, which are found by calling {@link #getActualMinimum getActualMinimum} and {@link #getActualMaximum getActualMaximum}. For most such fields, simple addition, subtraction, and modulus operations are sufficient to perform the roll. For week-related fields, the results of {@link #getFirstDayOfWeek getFirstDayOfWeek} and {@link #getMinimalDaysInFirstWeek getMinimalDaysInFirstWeek} are also necessary. Subclasses can override these two methods if their values differ from the defaults.

Subclasses that have fields for which the assumption of continuity breaks down must overide roll to handle those fields specially. For example, in the Hebrew calendar the month "Adar I" only occurs in leap years; in other years the calendar jumps from Shevat (month #4) to Adar (month #6). The {@link HebrewCalendar#roll HebrewCalendar.roll} method takes this into account, so that rolling the month of Shevat by one gives the proper result (Adar) in a non-leap year.

Parameters: field the calendar field to roll. amount the amount by which the field should be rolled.

Throws: IllegalArgumentException if the field is invalid or refers to a field that cannot be handled by this method.

See Also: Calendar Calendar

UNKNOWN: ICU 2.0

set

public final void set(int field, int value)
Sets the time field with the given value.

Parameters: field the given time field. value the value to be set for the given time field.

UNKNOWN: ICU 2.0

set

public final void set(int year, int month, int date)
Sets the values for the fields year, month, and date. Previous values of other fields are retained. If this is not desired, call clear first.

Parameters: year the value used to set the YEAR time field. month the value used to set the MONTH time field. Month value is 0-based. e.g., 0 for January. date the value used to set the DATE time field.

UNKNOWN: ICU 2.0

set

public final void set(int year, int month, int date, int hour, int minute)
Sets the values for the fields year, month, date, hour, and minute. Previous values of other fields are retained. If this is not desired, call clear first.

Parameters: year the value used to set the YEAR time field. month the value used to set the MONTH time field. Month value is 0-based. e.g., 0 for January. date the value used to set the DATE time field. hour the value used to set the HOUR_OF_DAY time field. minute the value used to set the MINUTE time field.

UNKNOWN: ICU 2.0

set

public final void set(int year, int month, int date, int hour, int minute, int second)
Sets the values for the fields year, month, date, hour, minute, and second. Previous values of other fields are retained. If this is not desired, call clear first.

Parameters: year the value used to set the YEAR time field. month the value used to set the MONTH time field. Month value is 0-based. e.g., 0 for January. date the value used to set the DATE time field. hour the value used to set the HOUR_OF_DAY time field. minute the value used to set the MINUTE time field. second the value used to set the SECOND time field.

UNKNOWN: ICU 2.0

setFirstDayOfWeek

public void setFirstDayOfWeek(int value)
Sets what the first day of the week is; e.g., Sunday in US, Monday in France.

Parameters: value the given first day of the week.

UNKNOWN: ICU 2.0

setLenient

public void setLenient(boolean lenient)
Specify whether or not date/time interpretation is to be lenient. With lenient interpretation, a date such as "February 942, 1996" will be treated as being equivalent to the 941st day after February 1, 1996. With strict interpretation, such dates will cause an exception to be thrown.

See Also: DateFormat

UNKNOWN: ICU 2.0

setMinimalDaysInFirstWeek

public void setMinimalDaysInFirstWeek(int value)
Sets what the minimal days required in the first week of the year are. For example, if the first week is defined as one that contains the first day of the first month of a year, call the method with value 1. If it must be a full week, use value 7.

Parameters: value the given minimal days required in the first week of the year.

UNKNOWN: ICU 2.0

setTime

public final void setTime(Date date)
Sets this Calendar's current time with the given Date.

Note: Calling setTime() with Date(Long.MAX_VALUE) or Date(Long.MIN_VALUE) may yield incorrect field values from get().

Parameters: date the given Date.

UNKNOWN: ICU 2.0

setTimeInMillis

public void setTimeInMillis(long millis)
Sets this Calendar's current time from the given long value.

Parameters: millis the new time in UTC milliseconds from the epoch.

UNKNOWN: ICU 2.0

setTimeZone

public void setTimeZone(TimeZone value)
Sets the time zone with the given time zone value.

Parameters: value the given time zone.

UNKNOWN: ICU 2.0

toString

public String toString()
Return a string representation of this calendar. This method is intended to be used only for debugging purposes, and the format of the returned string may vary between implementations. The returned string may be empty but may not be null.

Returns: a string representation of this calendar.

UNKNOWN: ICU 2.0

validateField

protected void validateField(int field)
Validate a single field of this calendar. Subclasses should override this method to validate any calendar-specific fields. Generic fields can be handled by Calendar.validateField().

See Also: Calendar

UNKNOWN: ICU 2.0

validateField

protected final void validateField(int field, int min, int max)
Validate a single field of this calendar given its minimum and maximum allowed value. If the field is out of range, throw a descriptive IllegalArgumentException. Subclasses may use this method in their implementation of {@link #validateField(int)}.

UNKNOWN: ICU 2.0

validateFields

protected void validateFields()
Ensure that each field is within its valid range by calling {@link #validateField(int)} on each field that has been set. This method should only be called if this calendar is not lenient.

See Also: Calendar Calendar

UNKNOWN: ICU 2.0

weekNumber

protected int weekNumber(int desiredDay, int dayOfPeriod, int dayOfWeek)
Return the week number of a day, within a period. This may be the week number in a year or the week number in a month. Usually this will be a value >= 1, but if some initial days of the period are excluded from week 1, because {@link #getMinimalDaysInFirstWeek getMinimalDaysInFirstWeek} is > 1, then the week number will be zero for those initial days. This method requires the day number and day of week for some known date in the period in order to determine the day of week on the desired day.

Subclassing:
This method is intended for use by subclasses in implementing their {@link #computeTime computeTime} and/or {@link #computeFields computeFields} methods. It is often useful in {@link #getActualMinimum getActualMinimum} and {@link #getActualMaximum getActualMaximum} as well.

This variant is handy for computing the week number of some other day of a period (often the first or last day of the period) when its day of the week is not known but the day number and day of week for some other day in the period (e.g. the current date) is known.

Parameters: desiredDay The {@link #DAY_OF_YEAR DAY_OF_YEAR} or {@link #DAY_OF_MONTH DAY_OF_MONTH} whose week number is desired. Should be 1 for the first day of the period. dayOfPeriod The {@link #DAY_OF_YEAR DAY_OF_YEAR} or {@link #DAY_OF_MONTH DAY_OF_MONTH} for a day in the period whose {@link #DAY_OF_WEEK DAY_OF_WEEK} is specified by the dayOfWeek parameter. Should be 1 for first day of period. dayOfWeek The {@link #DAY_OF_WEEK DAY_OF_WEEK} for the day corresponding to the dayOfPeriod parameter. 1-based with 1=Sunday.

Returns: The week number (one-based), or zero if the day falls before the first week because {@link #getMinimalDaysInFirstWeek getMinimalDaysInFirstWeek} is more than one.

UNKNOWN: ICU 2.0

weekNumber

protected final int weekNumber(int dayOfPeriod, int dayOfWeek)
Return the week number of a day, within a period. This may be the week number in a year, or the week number in a month. Usually this will be a value >= 1, but if some initial days of the period are excluded from week 1, because {@link #getMinimalDaysInFirstWeek getMinimalDaysInFirstWeek} is > 1, then the week number will be zero for those initial days. This method requires the day of week for the given date in order to determine the result.

Subclassing:
This method is intended for use by subclasses in implementing their {@link #computeTime computeTime} and/or {@link #computeFields computeFields} methods. It is often useful in {@link #getActualMinimum getActualMinimum} and {@link #getActualMaximum getActualMaximum} as well.

Parameters: dayOfPeriod The {@link #DAY_OF_YEAR DAY_OF_YEAR} or {@link #DAY_OF_MONTH DAY_OF_MONTH} whose week number is desired. Should be 1 for the first day of the period. dayOfWeek The {@link #DAY_OF_WEEK DAY_OF_WEEK} for the day corresponding to the dayOfPeriod parameter. 1-based with 1=Sunday.

Returns: The week number (one-based), or zero if the day falls before the first week because {@link #getMinimalDaysInFirstWeek getMinimalDaysInFirstWeek} is more than one.

UNKNOWN: ICU 2.0

Copyright (c) 2006 IBM Corporation and others.