Calendar is an abstract base class for converting between a UDate object and a set of integer fields such as YEAR, MONTH, DAY, HOUR, and so on. More...
#include <calendar.h>
computeGregorianFields(). More...
computeGregorianFields(). More...
computeGregorianFields(). More...
computeGregorianFields(). More...
Calendar is an abstract base class for converting between a UDate object and a set of integer fields such as YEAR, MONTH, DAY, HOUR, and so on.
(A UDate object represents a specific instant in time with millisecond precision. See UDate for information about the UDate class.)
Subclasses of Calendar interpret a UDate according to the rules of a specific calendar system. The most commonly used subclass of Calendar is GregorianCalendar. Other subclasses could represent the various types of lunar calendars in use in many parts of the world.
NOTE: (ICU 2.6) The subclass interface should be considered unstable - it WILL change.
Like other locale-sensitive classes, Calendar provides a static method, createInstance, for getting a generally useful object of this type. Calendar's createInstance method returns the appropriate Calendar subclass whose time fields have been initialized with the current date and time:
Calendar *rightNow = Calendar::createInstance(errCode);
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).
When computing a UDate from time fields, some special circumstances may arise: there may be insufficient information to compute the UDate (such as only year and month but no day in the month), there may be inconsistent information (such as "Tuesday, July 15, 1996" – July 15, 1996 is actually a Monday), or the input time might be ambiguous because of time zone transition.
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
Ambiguous Wall Clock Time. When time offset from UTC has changed, it produces an ambiguous time slot around the transition. For example, many US locations observe daylight saving time. On the date switching to daylight saving time in US, wall clock time jumps from 12:59 AM (standard) to 2:00 AM (daylight). Therefore, wall clock time from 1:00 AM to 1:59 AM do not exist on the date. When the input wall time fall into this missing time slot, the ICU Calendar resolves the time using the UTC offset before the transition by default. In this example, 1:30 AM is interpreted as 1:30 AM standard time (non-exist), so the final result will be 2:30 AM daylight time.
On the date switching back to standard time, wall clock time is moved back one hour at 2:00 AM. So wall clock time from 1:00 AM to 1:59 AM occur twice. In this case, the ICU Calendar resolves the time using the UTC offset after the transition by default. For example, 1:30 AM on the date is resolved as 1:30 AM standard time.
Ambiguous wall clock time resolution behaviors can be customized by Calendar APIs setRepeatedWallTimeOption and setSkippedWallTimeOption. These methods are available in ICU 49 or later versions.
Note: for some non-Gregorian calendars, different fields may be necessary for complete disambiguation. For example, a full specification of the historical 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:
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 DateFormat to format dates.
Calendar provides an API for field "rolling", where fields can be incremented or decremented, but wrap around. For example, rolling the month up in the date December 12, 1996 results in January 12, 1996.
Calendar also provides a date arithmetic function for adding the specified (signed) amount of time to a particular time field. For example, subtracting 5 days from the date September 12, 1996 results in September 7, 1996.
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. 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 ~5,800,000 BCE to ~5,800,000 CE. Programmers should use the protected constants in Calendar to specify an extremely early or extremely late date.
The Japanese calendar uses a combination of era name and year number. When an emperor of Japan abdicates and a new emperor ascends the throne, a new era is declared and year number is reset to 1. Even if the date of abdication is scheduled ahead of time, the new era name might not be announced until just before the date. In such case, ICU4C may include a start date of future era without actual era name, but not enabled by default. ICU4C users who want to test the behavior of the future era can enable the tentative era by:
ICU_ENABLE_TENTATIVE_ERA=true.Definition at line 190 of file calendar.h.
◆ anonymous enumSpecial values of stamp[].
Definition at line 1912 of file calendar.h.
◆ EAmpm ◆ EDateFieldsField IDs for date and time.
Used to specify date/time fields. ERA is calendar specific. Example ranges given are for illustration only; see specific Calendar subclasses for actual ranges.
Definition at line 199 of file calendar.h.
◆ EDaysOfWeekUseful constant for days of week.
Note: Calendar day-of-week is 1-based. Clients who create locale resources for the field of first-day-of-week should be aware of this. For instance, in US locale, first-day-of-week is set to 1, i.e., SUNDAY.
Definition at line 244 of file calendar.h.
◆ ELimitTypeLimit enums.
Not in sync with UCalendarLimitType (refers to internal fields).
Definition at line 1622 of file calendar.h.
◆ EMonths ◆ ~Calendar() virtual icu::Calendar::~Calendar ( ) virtual ◆ Calendar() [1/4]Constructs a Calendar with the default time zone as returned by TimeZone::createInstance(), and the default locale.
Copy constructor.
Constructs a Calendar with the given time zone and locale.
Clients are no longer responsible for deleting the given time zone object after it's adopted.
Constructs a Calendar with the given time zone and locale.
UDate Arithmetic function.
Adds the specified (signed) amount of time to the given time field, based on the calendar's rules. For example, to subtract 5 days from the current time of the calendar, call add(Calendar::DATE, -5). When adding on the month or Calendar::MONTH field, other fields like date might conflict and need to be changed. For instance, adding 1 month on the date 01/31/96 will result in 02/29/96. Adding a positive value always means moving forward in time, so for the Gregorian calendar, starting with 100 BC and adding +1 to year results in 99 BC (even though this actually reduces the numeric value of the field itself).
UDate Arithmetic function.
Adds the specified (signed) amount of time to the given time field, based on the calendar's rules. For example, to subtract 5 days from the current time of the calendar, call add(Calendar::DATE, -5). When adding on the month or Calendar::MONTH field, other fields like date might conflict and need to be changed. For instance, adding 1 month on the date 01/31/96 will result in 02/29/96. Adding a positive value always means moving forward in time, so for the Gregorian calendar, starting with 100 BC and adding +1 to year results in 99 BC (even though this actually reduces the numeric value of the field itself).
Sets the calendar's time zone to be the one passed in.
The Calendar takes ownership of the TimeZone; the caller is no longer responsible for deleting it. If the given time zone is nullptr, this function has no effect.
Returns true if this Calendar's current time is after "when"'s current time.
Returns true if this Calendar's current time is before "when"'s current time.
Clears the values of all the time fields, making them both unset and assigning them a value of zero.
The field values will be determined during the next resolving of time into time fields.
Clears the value in the given time field, both making it unset and assigning it a value of zero.
This field value will be determined during the next resolving of time into time fields. Clearing UCAL_ORDINAL_MONTH or UCAL_MONTH will clear both fields.
Create and return a polymorphic copy of this calendar.
Implemented in icu::GregorianCalendar.
◆ complete() void icu::Calendar::complete ( UErrorCode & status ) protectedRecomputes the current time from currently set fields, and then fills in any unset fields in the time field list.
Converts GMT as milliseconds to time field values.
This allows you to sync up the time field values with a new time that is set for the calendar. This method does NOT recompute the time first; to recompute the time, then the fields, use the method complete().
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.
◆ computeJulianDay() int32_t icu::Calendar::computeJulianDay ( UErrorCode & status ) protectedCompute the Julian day from fields.
Will determine whether to use the JULIAN_DAY field directly, or other fields.
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.
Converts Calendar's time field values to GMT as milliseconds.
This method can assume EXTENDED_YEAR has been set.
Creates a Calendar using the default timezone and the given locale.
Gets a Calendar using the given timezone and given locale.
The TimeZone is not adopted; the client is still responsible for deleting it.
Creates a Calendar using the given timezone and the default locale.
The TimeZone is not adopted; the client is still responsible for deleting it.
Creates a Calendar using the given timezone and given locale.
The Calendar takes ownership of zoneToAdopt; the client must not delete it.
Creates a Calendar using the given timezone and the default locale.
The Calendar takes ownership of zoneToAdopt; the client must not delete it.
Definition at line 2515 of file calendar.h.
◆ createInstance() [6/6]Creates a Calendar using the default timezone and locale.
Clients are responsible for deleting the object returned.
Compares the Calendar time, whereas Calendar::operator== compares the equality of Calendar objects.
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 addition 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, err); int m = cal->fieldDifference(when, Calendar::MONTH, err); int d = cal->fieldDifference(when, Calendar::DATE, err);
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, err); int m1 = cal->fieldDifference(date2, Calendar::MONTH, err); int d1 = cal->fieldDifference(date2, Calendar::DATE, err); cal->setTime(date2, err); int m2 = cal->fieldDifference(date1, Calendar::MONTH, err); int d2 = cal->fieldDifference(date1, Calendar::DATE, err);
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).
when, in terms of field.
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 addition 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, err); int m = cal->fieldDifference(when, Calendar::MONTH, err); int d = cal->fieldDifference(when, Calendar::DATE, err);
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, err); int m1 = cal->fieldDifference(date2, Calendar::MONTH, err); int d1 = cal->fieldDifference(date2, Calendar::DATE, err); cal->setTime(date2, err); int m2 = cal->fieldDifference(date1, Calendar::MONTH, err); int d2 = cal->fieldDifference(date1, Calendar::DATE, err);
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).
when, in terms of field.
Gets the value for a given time field.
Recalculate the current time field values if the time value has been changed by a call to setTime(). Return zero for unset fields if any fields have been explicitly set by a call to set(). To force a recomputation of all fields regardless of the previous state, call complete(). This method is semantically const, but may alter the object in memory.
Return the maximum value that this field could have, given the current date.
For example, with the date "Feb 3, 1997" and the DAY_OF_MONTH field, the actual maximum would be 28; for "Feb 3, 1996" it s 29. Similarly for a Hebrew calendar, for some years the actual maximum for MONTH is 12, and for others 13.
The version of this function on Calendar uses an iterative algorithm to determine the actual maximum value for the field. There is almost always a more efficient way to accomplish this (in most cases, you can simply return getMaximum()). GregorianCalendar overrides this function with a more efficient implementation.
Reimplemented in icu::GregorianCalendar.
◆ getActualMinimum() [1/2]Return the minimum value that this field could have, given the current date.
For the Gregorian calendar, this is the same as getMinimum() and getGreatestMinimum().
The version of this function on Calendar uses an iterative algorithm to determine the actual minimum value for the field. There is almost always a more efficient way to accomplish this (in most cases, you can simply return getMinimum()). GregorianCalendar overrides this function with a more efficient implementation.
Return the minimum value that this field could have, given the current date.
For the Gregorian calendar, this is the same as getMinimum() and getGreatestMinimum().
The version of this function on Calendar uses an iterative algorithm to determine the actual minimum value for the field. There is almost always a more efficient way to accomplish this (in most cases, you can simply return getMinimum()). GregorianCalendar overrides this function with a more efficient implementation.
Reimplemented in icu::GregorianCalendar.
◆ getAvailableLocales() [1/2]INTERNAL FOR 2.6 – Registration.
Return a StringEnumeration over the locales available at the time of the call, including registered locales.
Returns a list of the locales for which Calendars are installed.
Get the calendar type for given locale.
Returns whether the given day of the week is a weekday, a weekend day, or a day that transitions from one to the other, for the locale and calendar system associated with this Calendar (the locale's region is often the most determinant factor).
If a transition occurs at midnight, then the days before and after the transition will have the type UCAL_WEEKDAY or UCAL_WEEKEND. If a transition occurs at a time other than midnight, then the day of the transition will have the type UCAL_WEEKEND_ONSET or UCAL_WEEKEND_CEASE. In this case, the method getWeekendTransition() will return the point of transition.
Called by computeJulianDay.
Returns the default day (1-based) for the month, taking currently-set year and era into account. Defaults to 1 for Gregorian.
Called by computeJulianDay.
Returns the default month (0-based) for the year, taking year and era into account. Defaults to 0 for Gregorian, which doesn't care.
Returns a unique class ID POLYMORPHICALLY.
Pure virtual method. This method is to implement a simple version of RTTI, since not all C++ compilers support genuine RTTI. Polymorphic operator==() and clone() methods call this method.
Concrete subclasses of Calendar must implement getDynamicClassID() and also a static method and data member:
static UClassID getStaticClassID() { return (UClassID)&fgClassID; }
static char fgClassID;
Reimplemented from icu::UObject.
Implemented in icu::GregorianCalendar.
◆ getFieldResolutionTable()This API is for internal use only.
◆ getFirstDayOfWeek() [1/2]Gets what the first day of the week is; e.g., Sunday in US, Monday in France.
Gets what the first day of the week is; e.g., Sunday in US, Monday in France.
Gets the highest minimum value for the given field if varies.
Otherwise same as getMinimum(). For Gregorian, no difference.
Gets the highest minimum value for the given field if varies.
Otherwise same as getMinimum(). For Gregorian, no difference.
Given a key and a locale, returns an array of string values in a preferred order that would make a difference.
These are all and only those values where the open (creation) of the service with the locale formed from the input locale plus input keyword and that value has different behavior than creation with the input locale alone.
Gets the lowest maximum value for the given field if varies.
Otherwise same as getMaximum(). e.g., for Gregorian DAY_OF_MONTH, 28.
Gets the lowest maximum value for the given field if varies.
Otherwise same as getMaximum(). e.g., for Gregorian DAY_OF_MONTH, 28.
Return a limit for a field.
0..UCAL_MAX_FIELD limitType the type specifier for the limit
returns the local DOW, valid range 0..6
This API is for internal use only.
◆ getLocale()Get the locale for this calendar object.
You can choose between valid and actual locale.
Get the locale for this calendar object.
You can choose between valid and actual locale.
Gets the maximum value for the given time field.
e.g. for Gregorian DAY_OF_MONTH, 31.
Gets the maximum value for the given time field.
e.g. for Gregorian DAY_OF_MONTH, 31.
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.
Gets the minimum value for the given time field.
e.g., for Gregorian DAY_OF_MONTH, 1.
Gets the minimum value for the given time field.
e.g., for Gregorian DAY_OF_MONTH, 1.
Returns the current UTC (GMT) time measured in milliseconds since 0:00:00 on 1/1/70 (derived from the system time).
Gets the behavior for handling wall time repeating multiple times at negative time zone offset transitions.
UCAL_WALLTIME_FIRST or UCAL_WALLTIME_LAST.
Gets the behavior for handling skipped wall time at positive time zone offset transitions.
UCAL_WALLTIME_FIRST, UCAL_WALLTIME_LAST and UCAL_WALLTIME_NEXT_VALID.
Gets The Temporal monthCode value corresponding to the month for the date.
The value is a string identifier that starts with the literal grapheme "M" followed by two graphemes representing the zero-padded month number of the current month in a normal (non-leap) year and suffixed by an optional literal grapheme "L" if this is a leap month in a lunisolar calendar. The 25 possible values are "M01" .. "M13" and "M01L" .. "M12L". For the Hebrew calendar, the values are "M01" .. "M12" for non-leap year, and "M01" .. "M05", "M05L", "M06" .. "M12" for leap year. For the Chinese calendar, the values are "M01" .. "M12" for non-leap year and in leap year with another monthCode in "M01L" .. "M12L". For Coptic and Ethiopian calendar, the Temporal monthCode values for any years are "M01" to "M13".
Gets this Calendar's time as milliseconds.
May involve recalculation of time due to previous calls to set time field values. The time specified is non-local UTC (GMT) time. Although this method is const, this object may actually be changed (semantically const).
Definition at line 432 of file calendar.h.
◆ getTimeInMillis() double icu::Calendar::getTimeInMillis ( UErrorCode & status ) const protectedGets this Calendar's current time as a long.
Returns a reference to the time zone owned by this calendar.
The returned reference is only valid until clients make another call to adoptTimeZone or setTimeZone, or this Calendar is destroyed.
Returns the calendar type name string for this Calendar object.
The returned string is the legacy ICU calendar attribute value, for example, "gregorian" or "japanese".
See type="old type name" for the calendar attribute of locale IDs at http://www.unicode.org/reports/tr35/#Key_Type_Definitions
Sample code for getting the LDML/BCP 47 calendar key value:
const char *calType = cal->getType();
if (0 == strcmp(calType, "unknown")) {
} else {
string localeID("root@calendar=");
localeID.append(calType);
char langTag[100];
int32_t length =
uloc_toLanguageTag(localeID.c_str(), langTag, (int32_t)
sizeof(langTag),
true, &errorCode);
}
string lang(langTag, length);
size_t caPos = lang.find("-ca-");
lang.erase(0, caPos + 4);
}
U_CAPI int32_t uloc_toLanguageTag(const char *localeID, char *langtag, int32_t langtagCapacity, UBool strict, UErrorCode *err)
Returns a well-formed language tag for this locale ID.
UErrorCode
Standard ICU4C error code type, a substitute for exceptions.
@ U_ZERO_ERROR
No error, no warning.
#define U_FAILURE(x)
Does the error code indicate a failure?
Implemented in icu::GregorianCalendar.
◆ getWeekendTransition()Returns the time during the day at which the weekend begins or ends in this calendar system.
If getDayOfWeekType() returns UCAL_WEEKEND_ONSET for the specified dayOfWeek, return the time at which the weekend begins. If getDayOfWeekType() returns UCAL_WEEKEND_CEASE for the specified dayOfWeek, return the time at which the weekend ends. If getDayOfWeekType() returns some other UCalendarWeekdayType for the specified dayOfWeek, is it an error condition (U_ILLEGAL_ARGUMENT_ERROR).
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.
Reimplemented in icu::GregorianCalendar.
◆ handleComputeJulianDay()Subclasses may override this.
This method calls handleGetMonthLength() to obtain the calendar-specific month length.
Reimplemented in icu::GregorianCalendar.
◆ handleComputeMonthStart() virtual int64_t icu::Calendar::handleComputeMonthStart ( int32_t eyear, int32_t month, UBool useMonth, UErrorCode & status ) const protectedpure virtualReturn 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.
Implemented in icu::GregorianCalendar.
◆ handleGetExtendedYear() virtual int32_t icu::Calendar::handleGetExtendedYear ( UErrorCode & status ) protectedpure virtualReturn the extended year defined by the current fields.
This will use the UCAL_EXTENDED_YEAR field or the UCAL_YEAR and supra-year fields (such as UCAL_ERA) specific to the calendar system, depending on which set of fields is newer.
Implemented in icu::GregorianCalendar.
◆ handleGetExtendedYearFromWeekFields() virtual int32_t icu::Calendar::handleGetExtendedYearFromWeekFields ( int32_t yearWoy, int32_t woy, UErrorCode & status ) protectedvirtualSubclasses must override this to convert from week fields (YEAR_WOY and WEEK_OF_YEAR) to an extended year in the case where YEAR, EXTENDED_YEAR are not set.
The Calendar implementation assumes yearWoy is in extended gregorian form
Reimplemented in icu::GregorianCalendar.
◆ handleGetLimit()Subclass API for defining limits of different types.
Subclasses must implement this method to return limits for the following fields:
UCAL_ERA UCAL_YEAR UCAL_MONTH UCAL_WEEK_OF_YEAR UCAL_WEEK_OF_MONTH UCAL_DATE (DAY_OF_MONTH on Java) UCAL_DAY_OF_YEAR UCAL_DAY_OF_WEEK_IN_MONTH UCAL_YEAR_WOY UCAL_EXTENDED_YEAR
MINIMUM, GREATEST_MINIMUM, LEAST_MAXIMUM, or MAXIMUM
Implemented in icu::GregorianCalendar.
◆ handleGetMonthLength() virtual int32_t icu::Calendar::handleGetMonthLength ( int32_t extendedYear, int32_t month, UErrorCode & status ) const protectedvirtualReturn 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.
Reimplemented in icu::GregorianCalendar.
◆ handleGetYearLength() virtual int32_t icu::Calendar::handleGetYearLength ( int32_t eyear, UErrorCode & status ) const protectedvirtualReturn 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.
Reimplemented in icu::GregorianCalendar.
◆ haveDefaultCentury() virtual UBool icu::Calendar::haveDefaultCentury ( ) const pure virtualQueries if the current date for this Calendar is in Daylight Savings Time.
Returns true if the date is in a leap year.
Recalculate the current time field values if the time value has been changed by a call to * setTime(). This method is semantically const, but may alter the object in memory. A "leap year" is a year that contains more days than other years (for solar or lunar calendars) or more months than other years (for lunisolar calendars like Hebrew or Chinese), as defined in the ECMAScript Temporal proposal.
Gets the value for a given time field.
Subclasses can use this function to get field values without forcing recomputation of time.
Definition at line 1526 of file calendar.h.
◆ internalGet() [2/3]Gets the value for a given time field.
Subclasses can use this function to get field values without forcing recomputation of time.
Definition at line 1550 of file calendar.h.
◆ internalGet() [3/3]Gets the value for a given time field.
Subclasses can use this function to get field values without forcing recomputation of time. If the field's stamp is UNSET, the defaultValue is used.
Definition at line 1540 of file calendar.h.
◆ internalGetMonth() [1/2] virtual int32_t icu::Calendar::internalGetMonth ( int32_t defaultValue, UErrorCode & status ) const protectedvirtualUse this function instead of internalGet(UCAL_MONTH, defaultValue).
The implementation check the timestamp of UCAL_MONTH and UCAL_ORDINAL_MONTH and use the one set later. The subclass should override it to conver the value of UCAL_ORDINAL_MONTH to UCAL_MONTH correctly if UCAL_ORDINAL_MONTH has higher priority.
Use this function instead of internalGet(UCAL_MONTH).
The implementation check the timestamp of UCAL_MONTH and UCAL_ORDINAL_MONTH and use the one set later. The subclass should override it to conver the value of UCAL_ORDINAL_MONTH to UCAL_MONTH correctly if UCAL_ORDINAL_MONTH has higher priority.
Get the current time without recomputing.
Definition at line 1891 of file calendar.h.
◆ internalSet() [1/2] void icu::Calendar::internalSet ( EDateFields field, int32_t value ) protectedSets the value for a given time field.
This is a fast internal method for subclasses. It does not affect the areFieldsInSync, isTimeSet, or areAllFieldsSet flags.
Sets the value for a given time field.
Fast method for subclasses.
This is a fast internal method for subclasses. It does not affect the areFieldsInSync, isTimeSet, or areAllFieldsSet flags.
The caller must maintain fUserSetDSTOffset and fUserSetZoneOffset, as well as the isSet[] array.
Definition at line 2546 of file calendar.h.
◆ internalSetTime() void icu::Calendar::internalSetTime ( UDate time ) inlineprotectedSet the current time without affecting flags or fields.
Definition at line 1900 of file calendar.h.
◆ isEquivalentTo() virtual UBool icu::Calendar::isEquivalentTo ( const Calendar & other ) const virtualReturns 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 operator==() method to return true, the other Calendar must be set to the same time.
Reimplemented in icu::GregorianCalendar.
◆ isEra0CountingBackward() virtual bool icu::Calendar::isEra0CountingBackward ( ) const inlineprotectedvirtualThe year in this calendar is counting from 1 backward if the era is 0.
Reimplemented in icu::GregorianCalendar.
Definition at line 1557 of file calendar.h.
◆ isLenient() UBool icu::Calendar::isLenient ( ) constTells whether date/time interpretation is to be lenient.
Determines if the given time field has a value set.
This can affect in the resolving of time in Calendar. Unset fields have a value of zero, by definition.
Returns true if this Calendar's current date-time is in the weekend in this calendar system.
Returns true if the given UDate is in the weekend in this calendar system.
Convert a quasi Julian date to the day of the week.
The Julian date used here is not a true Julian date, since it is measured from midnight, not noon. Return value is one-based.
Creates a new Calendar from a Locale for the cache.
This method does not set the time or timezone in returned calendar.
Return the field that is newer, either defaultField, or alternateField.
If neither is newer or neither is set, return defaultField.
Determine the best stamp in a range.
Default assignment operator.
Compares the equality of two Calendar objects.
Objects of different subclasses are considered unequal. This comparison is very exacting; two Calendar objects must be in exactly the same state to be considered equal. To compare based on the represented time, use equals() instead.
Returns the time zone owned by this calendar.
The caller owns the returned object and must delete it when done. After this call, the new time zone associated with this Calendar is the default TimeZone as returned by TimeZone::createDefault().
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 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 roll and add.
Note: pinField is implemented in terms of getActualMinimum and 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.
Prepare this calendar for computing the actual minimum or maximum.
This method modifies this calendar's fields; it is called on a temporary calendar.
Register a new Calendar factory.
The factory will be adopted. INTERNAL in 2.6
Because ICU may choose to cache Calendars internally, this must be called at application startup, prior to any calls to Calendar::createInstance to avoid undefined behavior.
Given a precedence table, return the newest field combination in the table, or UCAL_FIELD_COUNT 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 kResolveRemap | 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 UCAL_FIELD_COUNT is returned.
Time Field Rolling function.
Rolls by the given amount on the given time field. For example, to roll the current date up by one day, call roll(Calendar::DATE, +1, status). When rolling on the month or Calendar::MONTH field, other fields like date might conflict and, need to be changed. For instance, rolling the month up on the date 01/31/96 will result in 02/29/96. Rolling by a positive value always means rolling forward in time (unless the limit of the field is reached, in which case it may pin or wrap), so for Gregorian calendar, starting with 100 BC and rolling the year by + 1 results in 99 BC. When eras have a definite beginning and end (as in the Chinese calendar, or as in most eras in the Japanese calendar) then rolling the year past either limit of the era will cause the year to wrap around. When eras only have a limit at one end, then attempting to roll the year past that limit will result in pinning the year at that limit. Note that for most calendars in which era 0 years move forward in time (such as Buddhist, Hebrew, or Islamic), it is possible for add or roll to result in negative years for era 0 (that is the only way to represent years before the calendar epoch). When rolling on the hour-in-day or Calendar::HOUR_OF_DAY field, it will roll the hour value in the range between 0 and 23, which is zero-based.
The only difference between roll() and add() is that roll() does not change the value of more significant fields when it reaches the minimum or maximum of its range, whereas add() does.
Reimplemented in icu::GregorianCalendar.
◆ roll() [2/4]Time Field Rolling function.
Rolls (up/down) a single unit of time on the given time field. For example, to roll the current date up by one day, call roll(Calendar::DATE, true). When rolling on the year or Calendar::YEAR field, it will roll the year value in the range between getMinimum(Calendar::YEAR) and the value returned by getMaximum(Calendar::YEAR). When rolling on the month or Calendar::MONTH field, other fields like date might conflict and, need to be changed. For instance, rolling the month up on the date 01/31/96 will result in 02/29/96. Rolling up always means rolling forward in time (unless the limit of the field is reached, in which case it may pin or wrap), so for Gregorian calendar, starting with 100 BC and rolling the year up results in 99 BC. When eras have a definite beginning and end (as in the Chinese calendar, or as in most eras in the Japanese calendar) then rolling the year past either limit of the era will cause the year to wrap around. When eras only have a limit at one end, then attempting to roll the year past that limit will result in pinning the year at that limit. Note that for most calendars in which era 0 years move forward in time (such as Buddhist, Hebrew, or Islamic), it is possible for add or roll to result in negative years for era 0 (that is the only way to represent years before the calendar epoch). When rolling on the hour-in-day or Calendar::HOUR_OF_DAY field, it will roll the hour value in the range between 0 and 23, which is zero-based.
NOTE: Do not use this method – use roll(EDateFields, int, UErrorCode&) instead.
Definition at line 2531 of file calendar.h.
◆ roll() [3/4]Time Field Rolling function.
Rolls by the given amount on the given time field. For example, to roll the current date up by one day, call roll(Calendar::DATE, +1, status). When rolling on the month or Calendar::MONTH field, other fields like date might conflict and, need to be changed. For instance, rolling the month up on the date 01/31/96 will result in 02/29/96. Rolling by a positive value always means rolling forward in time (unless the limit of the field is reached, in which case it may pin or wrap), so for Gregorian calendar, starting with 100 BC and rolling the year by + 1 results in 99 BC. When eras have a definite beginning and end (as in the Chinese calendar, or as in most eras in the Japanese calendar) then rolling the year past either limit of the era will cause the year to wrap around. When eras only have a limit at one end, then attempting to roll the year past that limit will result in pinning the year at that limit. Note that for most calendars in which era 0 years move forward in time (such as Buddhist, Hebrew, or Islamic), it is possible for add or roll to result in negative years for era 0 (that is the only way to represent years before the calendar epoch). When rolling on the hour-in-day or Calendar::HOUR_OF_DAY field, it will roll the hour value in the range between 0 and 23, which is zero-based.
The only difference between roll() and add() is that roll() does not change the value of more significant fields when it reaches the minimum or maximum of its range, whereas add() does.
Reimplemented in icu::GregorianCalendar.
◆ roll() [4/4]Time Field Rolling function.
Rolls (up/down) a single unit of time on the given time field. For example, to roll the current date up by one day, call roll(Calendar::DATE, true). When rolling on the year or Calendar::YEAR field, it will roll the year value in the range between getMinimum(Calendar::YEAR) and the value returned by getMaximum(Calendar::YEAR). When rolling on the month or Calendar::MONTH field, other fields like date might conflict and, need to be changed. For instance, rolling the month up on the date 01/31/96 will result in 02/29/96. Rolling up always means rolling forward in time (unless the limit of the field is reached, in which case it may pin or wrap), so for Gregorian calendar, starting with 100 BC and rolling the year up results in 99 BC. When eras have a definite beginning and end (as in the Chinese calendar, or as in most eras in the Japanese calendar) then rolling the year past either limit of the era will cause the year to wrap around. When eras only have a limit at one end, then attempting to roll the year past that limit will result in pinning the year at that limit. Note that for most calendars in which era 0 years move forward in time (such as Buddhist, Hebrew, or Islamic), it is possible for add or roll to result in negative years for era 0 (that is the only way to represent years before the calendar epoch). When rolling on the hour-in-day or Calendar::HOUR_OF_DAY field, it will roll the hour value in the range between 0 and 23, which is zero-based.
NOTE: Do not use this method – use roll(UCalendarDateFields, int, UErrorCode&) instead.
Definition at line 2524 of file calendar.h.
◆ set() [1/4] void icu::Calendar::set ( int32_t year, int32_t month, int32_t date )Sets the values for the fields YEAR, MONTH, and DATE.
Other field values are retained; call clear() first if this is not desired.
Sets the values for the fields YEAR, MONTH, DATE, HOUR_OF_DAY, and MINUTE.
Other field values are retained; call clear() first if this is not desired.
Sets the values for the fields YEAR, MONTH, DATE, HOUR_OF_DAY, MINUTE, and SECOND.
Other field values are retained; call clear() first if this is not desired.
Sets the given time field with the given value.
Sets what the first day of the week is; e.g., Sunday in US, Monday in France.
Specifies 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 error when computing time from the time field values representing the dates.
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.
Sets the behavior for handling wall time repeating multiple times at negative time zone offset transitions.
For example, 1:30 AM on November 6, 2011 in US Eastern time (America/New_York) occurs twice; 1:30 AM EDT, then 1:30 AM EST one hour later. When UCAL_WALLTIME_FIRST is used, the wall time 1:30AM in this example will be interpreted as 1:30 AM EDT (first occurrence). When UCAL_WALLTIME_LAST is used, it will be interpreted as 1:30 AM EST (last occurrence). The default value is UCAL_WALLTIME_LAST.
Note:When UCAL_WALLTIME_NEXT_VALID is not a valid option for this. When the argument is neither UCAL_WALLTIME_FIRST nor UCAL_WALLTIME_LAST, this method has no effect and will keep the current setting.
UCAL_WALLTIME_FIRST or UCAL_WALLTIME_LAST.
Sets the behavior for handling skipped wall time at positive time zone offset transitions.
For example, 2:30 AM on March 13, 2011 in US Eastern time (America/New_York) does not exist because the wall time jump from 1:59 AM EST to 3:00 AM EDT. When UCAL_WALLTIME_FIRST is used, 2:30 AM is interpreted as 30 minutes before 3:00 AM EDT, therefore, it will be resolved as 1:30 AM EST. When UCAL_WALLTIME_LAST is used, 2:30 AM is interpreted as 31 minutes after 1:59 AM EST, therefore, it will be resolved as 3:30 AM EDT. When UCAL_WALLTIME_NEXT_VALID is used, 2:30 AM will be resolved as next valid wall time, that is 3:00 AM EDT. The default value is UCAL_WALLTIME_LAST.
Note:This option is effective only when this calendar is lenient. When the calendar is strict, such non-existing wall time will cause an error.
UCAL_WALLTIME_FIRST, UCAL_WALLTIME_LAST and UCAL_WALLTIME_NEXT_VALID.
Sets The Temporal monthCode which is a string identifier that starts with the literal grapheme "M" followed by two graphemes representing the zero-padded month number of the current month in a normal (non-leap) year and suffixed by an optional literal grapheme "L" if this is a leap month in a lunisolar calendar.
The 25 possible values are "M01" .. "M13" and "M01L" .. "M12L". For Hebrew calendar, the values are "M01" .. "M12" for non-leap years, and "M01" .. "M05", "M05L", "M06" .. "M12" for leap year. For the Chinese calendar, the values are "M01" .. "M12" for non-leap year and in leap year with another monthCode in "M01L" .. "M12L". For Coptic and Ethiopian calendar, the Temporal monthCode values for any years are "M01" to "M13".
Sets this Calendar's current time with the given UDate.
The time specified should be in non-local UTC (GMT) time.
Definition at line 444 of file calendar.h.
◆ setTimeInMillis() void icu::Calendar::setTimeInMillis ( double millis, UErrorCode & status ) protectedSets this Calendar's current time from the given long value.
Sets the calendar's time zone to be the same as the one passed in.
The TimeZone passed in is not adopted; the client is still responsible for deleting it.
Unregister a previously-registered CalendarFactory using the key returned from the register call.
Key becomes invalid after a successful call and should not be used again. The CalendarFactory corresponding to the key will be deleted. INTERNAL in 2.6
Because ICU may choose to cache Calendars internally, this should be called during application shutdown, after all calls to Calendar::createInstance to avoid undefined behavior.
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().
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 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 computeTime and/or computeFields methods. It is often useful in getActualMinimum and getActualMaximum as well.
dayOfPeriod parameter. 1-based with 1=Sunday.
Definition at line 2564 of file calendar.h.
◆ weekNumber() [2/2] int32_t icu::Calendar::weekNumber ( int32_t desiredDay, int32_t dayOfPeriod, int32_t dayOfWeek ) protectedReturn 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 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 computeTime and/or computeFields methods. It is often useful in getActualMinimum and 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.
knownDayOfWeek parameter. Should be 1 for first day of period. dayOfWeek The DAY_OF_WEEK for the day corresponding to the knownDayOfPeriod parameter. 1-based with 1=Sunday.
The time fields containing values into which the millis is computed.
Definition at line 1906 of file calendar.h.
◆ kDatePrecedence ◆ kDOWPrecedence ◆ kMonthPrecedence ◆ kResolveRemap constexpr int32_t icu::Calendar::kResolveRemap = 32 staticconstexprprotectedValue to be bitwised "ORed" against resolve table field values for remapping.
Example: (UCAL_DATE | kResolveRemap) in 1st column will cause 'UCAL_DATE' to be returned, but will not examine the value of UCAL_DATE. Value for field resolution tables.
Definition at line 1797 of file calendar.h.
◆ kResolveSTOP constexpr int32_t icu::Calendar::kResolveSTOP = -1 staticconstexprprotectedMarker for end of resolve set (row or group).
Value for field resolution tables.
Definition at line 1787 of file calendar.h.
◆ kYearPrecedenceThe documentation for this class was generated from the following file:
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