xref: /aosp_15_r20/external/cronet/third_party/icu/source/i18n/unicode/calendar.h (revision 6777b5387eb2ff775bb5750e3f5d96f37fb7352b)
1 // © 2016 and later: Unicode, Inc. and others.
2 // License & terms of use: http://www.unicode.org/copyright.html
3 /*
4 ********************************************************************************
5 *   Copyright (C) 1997-2014, International Business Machines
6 *   Corporation and others.  All Rights Reserved.
7 ********************************************************************************
8 *
9 * File CALENDAR.H
10 *
11 * Modification History:
12 *
13 *   Date        Name        Description
14 *   04/22/97    aliu        Expanded and corrected comments and other header
15 *                           contents.
16 *   05/01/97    aliu        Made equals(), before(), after() arguments const.
17 *   05/20/97    aliu        Replaced fAreFieldsSet with fAreFieldsInSync and
18 *                           fAreAllFieldsSet.
19 *   07/27/98    stephen     Sync up with JDK 1.2
20 *   11/15/99    weiv        added YEAR_WOY and DOW_LOCAL
21 *                           to EDateFields
22 *    8/19/2002  srl         Removed Javaisms
23 *   11/07/2003  srl         Update, clean up documentation.
24 ********************************************************************************
25 */
26 
27 #ifndef CALENDAR_H
28 #define CALENDAR_H
29 
30 #include "unicode/utypes.h"
31 
32 #if U_SHOW_CPLUSPLUS_API
33 
34 /**
35  * \file
36  * \brief C++ API: Calendar object
37  */
38 #if !UCONFIG_NO_FORMATTING
39 
40 #include "unicode/uobject.h"
41 #include "unicode/locid.h"
42 #include "unicode/timezone.h"
43 #include "unicode/ucal.h"
44 #include "unicode/umisc.h"
45 
46 U_NAMESPACE_BEGIN
47 
48 class ICUServiceFactory;
49 
50 // Do not conditionalize the following with #ifndef U_HIDE_INTERNAL_API,
51 // it is a return type for a virtual method (@internal)
52 /**
53  * @internal
54  */
55 typedef int32_t UFieldResolutionTable[12][8];
56 
57 class BasicTimeZone;
58 /**
59  * `Calendar` is an abstract base class for converting between
60  * a `UDate` object and a set of integer fields such as
61  * `YEAR`, `MONTH`, `DAY`, `HOUR`, and so on.
62  * (A `UDate` object represents a specific instant in
63  * time with millisecond precision. See UDate
64  * for information about the `UDate` class.)
65  *
66  * Subclasses of `Calendar` interpret a `UDate`
67  * according to the rules of a specific calendar system.
68  * The most commonly used subclass of `Calendar` is
69  * `GregorianCalendar`. Other subclasses could represent
70  * the various types of lunar calendars in use in many parts of the world.
71  *
72  * **NOTE**: (ICU 2.6) The subclass interface should be considered unstable -
73  * it WILL change.
74  *
75  * Like other locale-sensitive classes, `Calendar` provides a
76  * static method, `createInstance`, for getting a generally useful
77  * object of this type. `Calendar`'s `createInstance` method
78  * returns the appropriate `Calendar` subclass whose
79  * time fields have been initialized with the current date and time:
80  *
81  *     Calendar *rightNow = Calendar::createInstance(errCode);
82  *
83  * A `Calendar` object can produce all the time field values
84  * needed to implement the date-time formatting for a particular language
85  * and calendar style (for example, Japanese-Gregorian, Japanese-Traditional).
86  *
87  * When computing a `UDate` from time fields, some special circumstances
88  * may arise: there may be insufficient information to compute the
89  * `UDate` (such as only year and month but no day in the month),
90  * there may be inconsistent information (such as "Tuesday, July 15, 1996"
91  * -- July 15, 1996 is actually a Monday), or the input time might be ambiguous
92  * because of time zone transition.
93  *
94  * **Insufficient information.** The calendar will use default
95  * information to specify the missing fields. This may vary by calendar; for
96  * the Gregorian calendar, the default for a field is the same as that of the
97  * start of the epoch: i.e., YEAR = 1970, MONTH = JANUARY, DATE = 1, etc.
98  *
99  * **Inconsistent information.** If fields conflict, the calendar
100  * will give preference to fields set more recently. For example, when
101  * determining the day, the calendar will look for one of the following
102  * combinations of fields.  The most recent combination, as determined by the
103  * most recently set single field, will be used.
104  *
105  *     MONTH + DAY_OF_MONTH
106  *     MONTH + WEEK_OF_MONTH + DAY_OF_WEEK
107  *     MONTH + DAY_OF_WEEK_IN_MONTH + DAY_OF_WEEK
108  *     DAY_OF_YEAR
109  *     DAY_OF_WEEK + WEEK_OF_YEAR
110  *
111  * For the time of day:
112  *
113  *     HOUR_OF_DAY
114  *     AM_PM + HOUR
115  *
116  * **Ambiguous Wall Clock Time.** When time offset from UTC has
117  * changed, it produces an ambiguous time slot around the transition. For example,
118  * many US locations observe daylight saving time. On the date switching to daylight
119  * saving time in US, wall clock time jumps from 12:59 AM (standard) to 2:00 AM
120  * (daylight). Therefore, wall clock time from 1:00 AM to 1:59 AM do not exist on
121  * the date. When the input wall time fall into this missing time slot, the ICU
122  * Calendar resolves the time using the UTC offset before the transition by default.
123  * In this example, 1:30 AM is interpreted as 1:30 AM standard time (non-exist),
124  * so the final result will be 2:30 AM daylight time.
125  *
126  * On the date switching back to standard time, wall clock time is moved back one
127  * hour at 2:00 AM. So wall clock time from 1:00 AM to 1:59 AM occur twice. In this
128  * case, the ICU Calendar resolves the time using the UTC offset after the transition
129  * by default. For example, 1:30 AM on the date is resolved as 1:30 AM standard time.
130  *
131  * Ambiguous wall clock time resolution behaviors can be customized by Calendar APIs
132  * {@link #setRepeatedWallTimeOption} and {@link #setSkippedWallTimeOption}.
133  * These methods are available in ICU 49 or later versions.
134  *
135  * **Note:** for some non-Gregorian calendars, different
136  * fields may be necessary for complete disambiguation. For example, a full
137  * specification of the historical Arabic astronomical calendar requires year,
138  * month, day-of-month *and* day-of-week in some cases.
139  *
140  * **Note:** There are certain possible ambiguities in
141  * interpretation of certain singular times, which are resolved in the
142  * following ways:
143  *
144  *   1. 24:00:00 "belongs" to the following day. That is,
145  *      23:59 on Dec 31, 1969 < 24:00 on Jan 1, 1970 < 24:01:00 on Jan 1, 1970
146  *   2. Although historically not precise, midnight also belongs to "am",
147  *      and noon belongs to "pm", so on the same day,
148  *      12:00 am (midnight) < 12:01 am, and 12:00 pm (noon) < 12:01 pm
149  *
150  * The date or time format strings are not part of the definition of a
151  * calendar, as those must be modifiable or overridable by the user at
152  * runtime. Use `DateFormat` to format dates.
153  *
154  * `Calendar` provides an API for field "rolling", where fields
155  * can be incremented or decremented, but wrap around. For example, rolling the
156  * month up in the date December 12, **1996** results in
157  * January 12, **1996**.
158  *
159  * `Calendar` also provides a date arithmetic function for
160  * adding the specified (signed) amount of time to a particular time field.
161  * For example, subtracting 5 days from the date `September 12, 1996`
162  * results in `September 7, 1996`.
163  *
164  * ***Supported range***
165  *
166  * The allowable range of `Calendar` has been narrowed. `GregorianCalendar` used
167  * to attempt to support the range of dates with millisecond values from
168  * `Long.MIN_VALUE` to `Long.MAX_VALUE`. The new `Calendar` protocol specifies the
169  * maximum range of supportable dates as those having Julian day numbers
170  * of `-0x7F000000` to `+0x7F000000`. This corresponds to years from ~5,800,000 BCE
171  * to ~5,800,000 CE. Programmers should use the protected constants in `Calendar` to
172  * specify an extremely early or extremely late date.
173  *
174  * <p>
175  * The Japanese calendar uses a combination of era name and year number.
176  * When an emperor of Japan abdicates and a new emperor ascends the throne,
177  * a new era is declared and year number is reset to 1. Even if the date of
178  * abdication is scheduled ahead of time, the new era name might not be
179  * announced until just before the date. In such case, ICU4C may include
180  * a start date of future era without actual era name, but not enabled
181  * by default. ICU4C users who want to test the behavior of the future era
182  * can enable the tentative era by:
183  * <ul>
184  * <li>Environment variable <code>ICU_ENABLE_TENTATIVE_ERA=true</code>.</li>
185  * </ul>
186  *
187  * @stable ICU 2.0
188  */
189 class U_I18N_API Calendar : public UObject {
190 public:
191 #ifndef U_FORCE_HIDE_DEPRECATED_API
192     /**
193      * Field IDs for date and time. Used to specify date/time fields. ERA is calendar
194      * specific. Example ranges given are for illustration only; see specific Calendar
195      * subclasses for actual ranges.
196      * @deprecated ICU 2.6. Use C enum UCalendarDateFields defined in ucal.h
197      */
198     enum EDateFields {
199 #ifndef U_HIDE_DEPRECATED_API
200 /*
201  * ERA may be defined on other platforms. To avoid any potential problems undefined it here.
202  */
203 #ifdef ERA
204 #undef ERA
205 #endif
206         ERA,                  // Example: 0..1
207         YEAR,                 // Example: 1..big number
208         MONTH,                // Example: 0..11
209         WEEK_OF_YEAR,         // Example: 1..53
210         WEEK_OF_MONTH,        // Example: 1..4
211         DATE,                 // Example: 1..31
212         DAY_OF_YEAR,          // Example: 1..365
213         DAY_OF_WEEK,          // Example: 1..7
214         DAY_OF_WEEK_IN_MONTH, // Example: 1..4, may be specified as -1
215         AM_PM,                // Example: 0..1
216         HOUR,                 // Example: 0..11
217         HOUR_OF_DAY,          // Example: 0..23
218         MINUTE,               // Example: 0..59
219         SECOND,               // Example: 0..59
220         MILLISECOND,          // Example: 0..999
221         ZONE_OFFSET,          // Example: -12*U_MILLIS_PER_HOUR..12*U_MILLIS_PER_HOUR
222         DST_OFFSET,           // Example: 0 or U_MILLIS_PER_HOUR
223         YEAR_WOY,             // 'Y' Example: 1..big number - Year of Week of Year
224         DOW_LOCAL,            // 'e' Example: 1..7 - Day of Week / Localized
225 
226         EXTENDED_YEAR,
227         JULIAN_DAY,
228         MILLISECONDS_IN_DAY,
229         IS_LEAP_MONTH,
230 
231         FIELD_COUNT = UCAL_FIELD_COUNT // See ucal.h for other fields.
232 #endif /* U_HIDE_DEPRECATED_API */
233     };
234 #endif  // U_FORCE_HIDE_DEPRECATED_API
235 
236 #ifndef U_HIDE_DEPRECATED_API
237     /**
238      * Useful constant for days of week. Note: Calendar day-of-week is 1-based. Clients
239      * who create locale resources for the field of first-day-of-week should be aware of
240      * this. For instance, in US locale, first-day-of-week is set to 1, i.e., SUNDAY.
241      * @deprecated ICU 2.6. Use C enum UCalendarDaysOfWeek defined in ucal.h
242      */
243     enum EDaysOfWeek {
244         SUNDAY = 1,
245         MONDAY,
246         TUESDAY,
247         WEDNESDAY,
248         THURSDAY,
249         FRIDAY,
250         SATURDAY
251     };
252 
253     /**
254      * Useful constants for month. Note: Calendar month is 0-based.
255      * @deprecated ICU 2.6. Use C enum UCalendarMonths defined in ucal.h
256      */
257     enum EMonths {
258         JANUARY,
259         FEBRUARY,
260         MARCH,
261         APRIL,
262         MAY,
263         JUNE,
264         JULY,
265         AUGUST,
266         SEPTEMBER,
267         OCTOBER,
268         NOVEMBER,
269         DECEMBER,
270         UNDECIMBER
271     };
272 
273     /**
274      * Useful constants for hour in 12-hour clock. Used in GregorianCalendar.
275      * @deprecated ICU 2.6. Use C enum UCalendarAMPMs defined in ucal.h
276      */
277     enum EAmpm {
278         AM,
279         PM
280     };
281 #endif  /* U_HIDE_DEPRECATED_API */
282 
283     /**
284      * destructor
285      * @stable ICU 2.0
286      */
287     virtual ~Calendar();
288 
289     /**
290      * Create and return a polymorphic copy of this calendar.
291      *
292      * @return    a polymorphic copy of this calendar.
293      * @stable ICU 2.0
294      */
295     virtual Calendar* clone() const = 0;
296 
297     /**
298      * Creates a Calendar using the default timezone and locale. Clients are responsible
299      * for deleting the object returned.
300      *
301      * @param success  Indicates the success/failure of Calendar creation. Filled in
302      *                 with U_ZERO_ERROR if created successfully, set to a failure result
303      *                 otherwise. U_MISSING_RESOURCE_ERROR will be returned if the resource data
304      *                 requests a calendar type which has not been installed.
305      * @return         A Calendar if created successfully. nullptr otherwise.
306      * @stable ICU 2.0
307      */
308     static Calendar* U_EXPORT2 createInstance(UErrorCode& success);
309 
310     /**
311      * Creates a Calendar using the given timezone and the default locale.
312      * The Calendar takes ownership of zoneToAdopt; the
313      * client must not delete it.
314      *
315      * @param zoneToAdopt  The given timezone to be adopted.
316      * @param success      Indicates the success/failure of Calendar creation. Filled in
317      *                     with U_ZERO_ERROR if created successfully, set to a failure result
318      *                     otherwise.
319      * @return             A Calendar if created successfully. nullptr otherwise.
320      * @stable ICU 2.0
321      */
322     static Calendar* U_EXPORT2 createInstance(TimeZone* zoneToAdopt, UErrorCode& success);
323 
324     /**
325      * Creates a Calendar using the given timezone and the default locale.  The TimeZone
326      * is _not_ adopted; the client is still responsible for deleting it.
327      *
328      * @param zone  The timezone.
329      * @param success      Indicates the success/failure of Calendar creation. Filled in
330      *                     with U_ZERO_ERROR if created successfully, set to a failure result
331      *                     otherwise.
332      * @return             A Calendar if created successfully. nullptr otherwise.
333      * @stable ICU 2.0
334      */
335     static Calendar* U_EXPORT2 createInstance(const TimeZone& zone, UErrorCode& success);
336 
337     /**
338      * Creates a Calendar using the default timezone and the given locale.
339      *
340      * @param aLocale  The given locale.
341      * @param success  Indicates the success/failure of Calendar creation. Filled in
342      *                 with U_ZERO_ERROR if created successfully, set to a failure result
343      *                 otherwise.
344      * @return         A Calendar if created successfully. nullptr otherwise.
345      * @stable ICU 2.0
346      */
347     static Calendar* U_EXPORT2 createInstance(const Locale& aLocale, UErrorCode& success);
348 
349     /**
350      * Creates a Calendar using the given timezone and given locale.
351      * The Calendar takes ownership of zoneToAdopt; the
352      * client must not delete it.
353      *
354      * @param zoneToAdopt  The given timezone to be adopted.
355      * @param aLocale      The given locale.
356      * @param success      Indicates the success/failure of Calendar creation. Filled in
357      *                     with U_ZERO_ERROR if created successfully, set to a failure result
358      *                     otherwise.
359      * @return             A Calendar if created successfully. nullptr otherwise.
360      * @stable ICU 2.0
361      */
362     static Calendar* U_EXPORT2 createInstance(TimeZone* zoneToAdopt, const Locale& aLocale, UErrorCode& success);
363 
364     /**
365      * Gets a Calendar using the given timezone and given locale.  The TimeZone
366      * is _not_ adopted; the client is still responsible for deleting it.
367      *
368      * @param zone         The given timezone.
369      * @param aLocale      The given locale.
370      * @param success      Indicates the success/failure of Calendar creation. Filled in
371      *                     with U_ZERO_ERROR if created successfully, set to a failure result
372      *                     otherwise.
373      * @return             A Calendar if created successfully. nullptr otherwise.
374      * @stable ICU 2.0
375      */
376     static Calendar* U_EXPORT2 createInstance(const TimeZone& zone, const Locale& aLocale, UErrorCode& success);
377 
378     /**
379      * Returns a list of the locales for which Calendars are installed.
380      *
381      * @param count  Number of locales returned.
382      * @return       An array of Locale objects representing the set of locales for which
383      *               Calendars are installed.  The system retains ownership of this list;
384      *               the caller must NOT delete it. Does not include user-registered Calendars.
385      * @stable ICU 2.0
386      */
387     static const Locale* U_EXPORT2 getAvailableLocales(int32_t& count);
388 
389 
390     /**
391      * Given a key and a locale, returns an array of string values in a preferred
392      * order that would make a difference. These are all and only those values where
393      * the open (creation) of the service with the locale formed from the input locale
394      * plus input keyword and that value has different behavior than creation with the
395      * input locale alone.
396      * @param key           one of the keys supported by this service.  For now, only
397      *                      "calendar" is supported.
398      * @param locale        the locale
399      * @param commonlyUsed  if set to true it will return only commonly used values
400      *                      with the given locale in preferred order.  Otherwise,
401      *                      it will return all the available values for the locale.
402      * @param status        ICU Error Code
403      * @return a string enumeration over keyword values for the given key and the locale.
404      * @stable ICU 4.2
405      */
406     static StringEnumeration* U_EXPORT2 getKeywordValuesForLocale(const char* key,
407                     const Locale& locale, UBool commonlyUsed, UErrorCode& status);
408 
409     /**
410      * Returns the current UTC (GMT) time measured in milliseconds since 0:00:00 on 1/1/70
411      * (derived from the system time).
412      *
413      * @return   The current UTC time in milliseconds.
414      * @stable ICU 2.0
415      */
416     static UDate U_EXPORT2 getNow(void);
417 
418     /**
419      * Gets this Calendar's time as milliseconds. May involve recalculation of time due
420      * to previous calls to set time field values. The time specified is non-local UTC
421      * (GMT) time. Although this method is const, this object may actually be changed
422      * (semantically const).
423      *
424      * @param status  Output param set to success/failure code on exit. If any value
425      *                previously set in the time field is invalid or restricted by
426      *                leniency, this will be set to an error status.
427      * @return        The current time in UTC (GMT) time, or zero if the operation
428      *                failed.
429      * @stable ICU 2.0
430      */
getTime(UErrorCode & status)431     inline UDate getTime(UErrorCode& status) const { return getTimeInMillis(status); }
432 
433     /**
434      * Sets this Calendar's current time with the given UDate. The time specified should
435      * be in non-local UTC (GMT) time.
436      *
437      * @param date  The given UDate in UTC (GMT) time.
438      * @param status  Output param set to success/failure code on exit. If any value
439      *                set in the time field is invalid or restricted by
440      *                leniency, this will be set to an error status.
441      * @stable ICU 2.0
442      */
setTime(UDate date,UErrorCode & status)443     inline void setTime(UDate date, UErrorCode& status) { setTimeInMillis(date, status); }
444 
445     /**
446      * Compares the equality of two Calendar objects. Objects of different subclasses
447      * are considered unequal. This comparison is very exacting; two Calendar objects
448      * must be in exactly the same state to be considered equal. To compare based on the
449      * represented time, use equals() instead.
450      *
451      * @param that  The Calendar object to be compared with.
452      * @return      true if the given Calendar is the same as this Calendar; false
453      *              otherwise.
454      * @stable ICU 2.0
455      */
456     virtual bool operator==(const Calendar& that) const;
457 
458     /**
459      * Compares the inequality of two Calendar objects.
460      *
461      * @param that  The Calendar object to be compared with.
462      * @return      true if the given Calendar is not the same as this Calendar; false
463      *              otherwise.
464      * @stable ICU 2.0
465      */
466     bool operator!=(const Calendar& that) const {return !operator==(that);}
467 
468     /**
469      * Returns true if the given Calendar object is equivalent to this
470      * one.  An equivalent Calendar will behave exactly as this one
471      * does, but it may be set to a different time.  By contrast, for
472      * the operator==() method to return true, the other Calendar must
473      * be set to the same time.
474      *
475      * @param other the Calendar to be compared with this Calendar
476      * @stable ICU 2.4
477      */
478     virtual UBool isEquivalentTo(const Calendar& other) const;
479 
480     /**
481      * Compares the Calendar time, whereas Calendar::operator== compares the equality of
482      * Calendar objects.
483      *
484      * @param when    The Calendar to be compared with this Calendar. Although this is a
485      *                const parameter, the object may be modified physically
486      *                (semantically const).
487      * @param status  Output param set to success/failure code on exit. If any value
488      *                previously set in the time field is invalid or restricted by
489      *                leniency, this will be set to an error status.
490      * @return        True if the current time of this Calendar is equal to the time of
491      *                Calendar when; false otherwise.
492      * @stable ICU 2.0
493      */
494     UBool equals(const Calendar& when, UErrorCode& status) const;
495 
496     /**
497      * Returns true if this Calendar's current time is before "when"'s current time.
498      *
499      * @param when    The Calendar to be compared with this Calendar. Although this is a
500      *                const parameter, the object may be modified physically
501      *                (semantically const).
502      * @param status  Output param set to success/failure code on exit. If any value
503      *                previously set in the time field is invalid or restricted by
504      *                leniency, this will be set to an error status.
505      * @return        True if the current time of this Calendar is before the time of
506      *                Calendar when; false otherwise.
507      * @stable ICU 2.0
508      */
509     UBool before(const Calendar& when, UErrorCode& status) const;
510 
511     /**
512      * Returns true if this Calendar's current time is after "when"'s current time.
513      *
514      * @param when    The Calendar to be compared with this Calendar. Although this is a
515      *                const parameter, the object may be modified physically
516      *                (semantically const).
517      * @param status  Output param set to success/failure code on exit. If any value
518      *                previously set in the time field is invalid or restricted by
519      *                leniency, this will be set to an error status.
520      * @return        True if the current time of this Calendar is after the time of
521      *                Calendar when; false otherwise.
522      * @stable ICU 2.0
523      */
524     UBool after(const Calendar& when, UErrorCode& status) const;
525 
526 #ifndef U_FORCE_HIDE_DEPRECATED_API
527     /**
528      * UDate Arithmetic function. Adds the specified (signed) amount of time to the given
529      * time field, based on the calendar's rules. For example, to subtract 5 days from
530      * the current time of the calendar, call add(Calendar::DATE, -5). When adding on
531      * the month or Calendar::MONTH field, other fields like date might conflict and
532      * need to be changed. For instance, adding 1 month on the date 01/31/96 will result
533      * in 02/29/96.
534      * Adding a positive value always means moving forward in time, so for the Gregorian calendar,
535      * starting with 100 BC and adding +1 to year results in 99 BC (even though this actually reduces
536      * the numeric value of the field itself).
537      *
538      * @param field   Specifies which date field to modify.
539      * @param amount  The amount of time to be added to the field, in the natural unit
540      *                for that field (e.g., days for the day fields, hours for the hour
541      *                field.)
542      * @param status  Output param set to success/failure code on exit. If any value
543      *                previously set in the time field is invalid or restricted by
544      *                leniency, this will be set to an error status.
545      * @deprecated ICU 2.6. use add(UCalendarDateFields field, int32_t amount, UErrorCode& status) instead.
546      */
547     virtual void add(EDateFields field, int32_t amount, UErrorCode& status);
548 #endif  // U_FORCE_HIDE_DEPRECATED_API
549 
550     /**
551      * UDate Arithmetic function. Adds the specified (signed) amount of time to the given
552      * time field, based on the calendar's rules. For example, to subtract 5 days from
553      * the current time of the calendar, call add(Calendar::DATE, -5). When adding on
554      * the month or Calendar::MONTH field, other fields like date might conflict and
555      * need to be changed. For instance, adding 1 month on the date 01/31/96 will result
556      * in 02/29/96.
557      * Adding a positive value always means moving forward in time, so for the Gregorian calendar,
558      * starting with 100 BC and adding +1 to year results in 99 BC (even though this actually reduces
559      * the numeric value of the field itself).
560      *
561      * @param field   Specifies which date field to modify.
562      * @param amount  The amount of time to be added to the field, in the natural unit
563      *                for that field (e.g., days for the day fields, hours for the hour
564      *                field.)
565      * @param status  Output param set to success/failure code on exit. If any value
566      *                previously set in the time field is invalid or restricted by
567      *                leniency, this will be set to an error status.
568      * @stable ICU 2.6.
569      */
570     virtual void add(UCalendarDateFields field, int32_t amount, UErrorCode& status);
571 
572 #ifndef U_HIDE_DEPRECATED_API
573     /**
574      * Time Field Rolling function. Rolls (up/down) a single unit of time on the given
575      * time field. For example, to roll the current date up by one day, call
576      * roll(Calendar::DATE, true). When rolling on the year or Calendar::YEAR field, it
577      * will roll the year value in the range between getMinimum(Calendar::YEAR) and the
578      * value returned by getMaximum(Calendar::YEAR). When rolling on the month or
579      * Calendar::MONTH field, other fields like date might conflict and, need to be
580      * changed. For instance, rolling the month up on the date 01/31/96 will result in
581      * 02/29/96. Rolling up always means rolling forward in time (unless the limit of the
582      * field is reached, in which case it may pin or wrap), so for Gregorian calendar,
583      * starting with 100 BC and rolling the year up results in 99 BC.
584      * When eras have a definite beginning and end (as in the Chinese calendar, or as in
585      * most eras in the Japanese calendar) then rolling the year past either limit of the
586      * era will cause the year to wrap around. When eras only have a limit at one end,
587      * then attempting to roll the year past that limit will result in pinning the year
588      * at that limit. Note that for most calendars in which era 0 years move forward in
589      * time (such as Buddhist, Hebrew, or Islamic), it is possible for add or roll to
590      * result in negative years for era 0 (that is the only way to represent years before
591      * the calendar epoch).
592      * When rolling on the hour-in-day or Calendar::HOUR_OF_DAY field, it will roll the
593      * hour value in the range between 0 and 23, which is zero-based.
594      * <P>
595      * NOTE: Do not use this method -- use roll(EDateFields, int, UErrorCode&) instead.
596      *
597      * @param field   The time field.
598      * @param up      Indicates if the value of the specified time field is to be rolled
599      *                up or rolled down. Use true if rolling up, false otherwise.
600      * @param status  Output param set to success/failure code on exit. If any value
601      *                previously set in the time field is invalid or restricted by
602      *                leniency, this will be set to an error status.
603      * @deprecated ICU 2.6. Use roll(UCalendarDateFields field, UBool up, UErrorCode& status) instead.
604      */
605     inline void roll(EDateFields field, UBool up, UErrorCode& status);
606 #endif  /* U_HIDE_DEPRECATED_API */
607 
608     /**
609      * Time Field Rolling function. Rolls (up/down) a single unit of time on the given
610      * time field. For example, to roll the current date up by one day, call
611      * roll(Calendar::DATE, true). When rolling on the year or Calendar::YEAR field, it
612      * will roll the year value in the range between getMinimum(Calendar::YEAR) and the
613      * value returned by getMaximum(Calendar::YEAR). When rolling on the month or
614      * Calendar::MONTH field, other fields like date might conflict and, need to be
615      * changed. For instance, rolling the month up on the date 01/31/96 will result in
616      * 02/29/96. Rolling up always means rolling forward in time (unless the limit of the
617      * field is reached, in which case it may pin or wrap), so for Gregorian calendar,
618      * starting with 100 BC and rolling the year up results in 99 BC.
619      * When eras have a definite beginning and end (as in the Chinese calendar, or as in
620      * most eras in the Japanese calendar) then rolling the year past either limit of the
621      * era will cause the year to wrap around. When eras only have a limit at one end,
622      * then attempting to roll the year past that limit will result in pinning the year
623      * at that limit. Note that for most calendars in which era 0 years move forward in
624      * time (such as Buddhist, Hebrew, or Islamic), it is possible for add or roll to
625      * result in negative years for era 0 (that is the only way to represent years before
626      * the calendar epoch).
627      * When rolling on the hour-in-day or Calendar::HOUR_OF_DAY field, it will roll the
628      * hour value in the range between 0 and 23, which is zero-based.
629      * <P>
630      * NOTE: Do not use this method -- use roll(UCalendarDateFields, int, UErrorCode&) instead.
631      *
632      * @param field   The time field.
633      * @param up      Indicates if the value of the specified time field is to be rolled
634      *                up or rolled down. Use true if rolling up, false otherwise.
635      * @param status  Output param set to success/failure code on exit. If any value
636      *                previously set in the time field is invalid or restricted by
637      *                leniency, this will be set to an error status.
638      * @stable ICU 2.6.
639      */
640     inline void roll(UCalendarDateFields field, UBool up, UErrorCode& status);
641 
642 #ifndef U_FORCE_HIDE_DEPRECATED_API
643     /**
644      * Time Field Rolling function. Rolls by the given amount on the given
645      * time field. For example, to roll the current date up by one day, call
646      * roll(Calendar::DATE, +1, status). When rolling on the month or
647      * Calendar::MONTH field, other fields like date might conflict and, need to be
648      * changed. For instance, rolling the month up on the date 01/31/96 will result in
649      * 02/29/96. Rolling by a positive value always means rolling forward in time (unless
650      * the limit of the field is reached, in which case it may pin or wrap), so for
651      * Gregorian calendar, starting with 100 BC and rolling the year by + 1 results in 99 BC.
652      * When eras have a definite beginning and end (as in the Chinese calendar, or as in
653      * most eras in the Japanese calendar) then rolling the year past either limit of the
654      * era will cause the year to wrap around. When eras only have a limit at one end,
655      * then attempting to roll the year past that limit will result in pinning the year
656      * at that limit. Note that for most calendars in which era 0 years move forward in
657      * time (such as Buddhist, Hebrew, or Islamic), it is possible for add or roll to
658      * result in negative years for era 0 (that is the only way to represent years before
659      * the calendar epoch).
660      * When rolling on the hour-in-day or Calendar::HOUR_OF_DAY field, it will roll the
661      * hour value in the range between 0 and 23, which is zero-based.
662      * <P>
663      * The only difference between roll() and add() is that roll() does not change
664      * the value of more significant fields when it reaches the minimum or maximum
665      * of its range, whereas add() does.
666      *
667      * @param field   The time field.
668      * @param amount  Indicates amount to roll.
669      * @param status  Output param set to success/failure code on exit. If any value
670      *                previously set in the time field is invalid, this will be set to
671      *                an error status.
672      * @deprecated ICU 2.6. Use roll(UCalendarDateFields field, int32_t amount, UErrorCode& status) instead.
673      */
674     virtual void roll(EDateFields field, int32_t amount, UErrorCode& status);
675 #endif  // U_FORCE_HIDE_DEPRECATED_API
676 
677     /**
678      * Time Field Rolling function. Rolls by the given amount on the given
679      * time field. For example, to roll the current date up by one day, call
680      * roll(Calendar::DATE, +1, status). When rolling on the month or
681      * Calendar::MONTH field, other fields like date might conflict and, need to be
682      * changed. For instance, rolling the month up on the date 01/31/96 will result in
683      * 02/29/96. Rolling by a positive value always means rolling forward in time (unless
684      * the limit of the field is reached, in which case it may pin or wrap), so for
685      * Gregorian calendar, starting with 100 BC and rolling the year by + 1 results in 99 BC.
686      * When eras have a definite beginning and end (as in the Chinese calendar, or as in
687      * most eras in the Japanese calendar) then rolling the year past either limit of the
688      * era will cause the year to wrap around. When eras only have a limit at one end,
689      * then attempting to roll the year past that limit will result in pinning the year
690      * at that limit. Note that for most calendars in which era 0 years move forward in
691      * time (such as Buddhist, Hebrew, or Islamic), it is possible for add or roll to
692      * result in negative years for era 0 (that is the only way to represent years before
693      * the calendar epoch).
694      * When rolling on the hour-in-day or Calendar::HOUR_OF_DAY field, it will roll the
695      * hour value in the range between 0 and 23, which is zero-based.
696      * <P>
697      * The only difference between roll() and add() is that roll() does not change
698      * the value of more significant fields when it reaches the minimum or maximum
699      * of its range, whereas add() does.
700      *
701      * @param field   The time field.
702      * @param amount  Indicates amount to roll.
703      * @param status  Output param set to success/failure code on exit. If any value
704      *                previously set in the time field is invalid, this will be set to
705      *                an error status.
706      * @stable ICU 2.6.
707      */
708     virtual void roll(UCalendarDateFields field, int32_t amount, UErrorCode& status);
709 
710 #ifndef U_FORCE_HIDE_DEPRECATED_API
711     /**
712      * Return the difference between the given time and the time this
713      * calendar object is set to.  If this calendar is set
714      * <em>before</em> the given time, the returned value will be
715      * positive.  If this calendar is set <em>after</em> the given
716      * time, the returned value will be negative.  The
717      * <code>field</code> parameter specifies the units of the return
718      * value.  For example, if <code>fieldDifference(when,
719      * Calendar::MONTH)</code> returns 3, then this calendar is set to
720      * 3 months before <code>when</code>, and possibly some addition
721      * time less than one month.
722      *
723      * <p>As a side effect of this call, this calendar is advanced
724      * toward <code>when</code> by the given amount.  That is, calling
725      * this method has the side effect of calling <code>add(field,
726      * n)</code>, where <code>n</code> is the return value.
727      *
728      * <p>Usage: To use this method, call it first with the largest
729      * field of interest, then with progressively smaller fields.  For
730      * example:
731      *
732      * <pre>
733      * int y = cal->fieldDifference(when, Calendar::YEAR, err);
734      * int m = cal->fieldDifference(when, Calendar::MONTH, err);
735      * int d = cal->fieldDifference(when, Calendar::DATE, err);</pre>
736      *
737      * computes the difference between <code>cal</code> and
738      * <code>when</code> in years, months, and days.
739      *
740      * <p>Note: <code>fieldDifference()</code> is
741      * <em>asymmetrical</em>.  That is, in the following code:
742      *
743      * <pre>
744      * cal->setTime(date1, err);
745      * int m1 = cal->fieldDifference(date2, Calendar::MONTH, err);
746      * int d1 = cal->fieldDifference(date2, Calendar::DATE, err);
747      * cal->setTime(date2, err);
748      * int m2 = cal->fieldDifference(date1, Calendar::MONTH, err);
749      * int d2 = cal->fieldDifference(date1, Calendar::DATE, err);</pre>
750      *
751      * one might expect that <code>m1 == -m2 && d1 == -d2</code>.
752      * However, this is not generally the case, because of
753      * irregularities in the underlying calendar system (e.g., the
754      * Gregorian calendar has a varying number of days per month).
755      *
756      * @param when the date to compare this calendar's time to
757      * @param field the field in which to compute the result
758      * @param status  Output param set to success/failure code on exit. If any value
759      *                previously set in the time field is invalid, this will be set to
760      *                an error status.
761      * @return the difference, either positive or negative, between
762      * this calendar's time and <code>when</code>, in terms of
763      * <code>field</code>.
764      * @deprecated ICU 2.6. Use fieldDifference(UDate when, UCalendarDateFields field, UErrorCode& status).
765      */
766     virtual int32_t fieldDifference(UDate when, EDateFields field, UErrorCode& status);
767 #endif  // U_FORCE_HIDE_DEPRECATED_API
768 
769     /**
770      * Return the difference between the given time and the time this
771      * calendar object is set to.  If this calendar is set
772      * <em>before</em> the given time, the returned value will be
773      * positive.  If this calendar is set <em>after</em> the given
774      * time, the returned value will be negative.  The
775      * <code>field</code> parameter specifies the units of the return
776      * value.  For example, if <code>fieldDifference(when,
777      * Calendar::MONTH)</code> returns 3, then this calendar is set to
778      * 3 months before <code>when</code>, and possibly some addition
779      * time less than one month.
780      *
781      * <p>As a side effect of this call, this calendar is advanced
782      * toward <code>when</code> by the given amount.  That is, calling
783      * this method has the side effect of calling <code>add(field,
784      * n)</code>, where <code>n</code> is the return value.
785      *
786      * <p>Usage: To use this method, call it first with the largest
787      * field of interest, then with progressively smaller fields.  For
788      * example:
789      *
790      * <pre>
791      * int y = cal->fieldDifference(when, Calendar::YEAR, err);
792      * int m = cal->fieldDifference(when, Calendar::MONTH, err);
793      * int d = cal->fieldDifference(when, Calendar::DATE, err);</pre>
794      *
795      * computes the difference between <code>cal</code> and
796      * <code>when</code> in years, months, and days.
797      *
798      * <p>Note: <code>fieldDifference()</code> is
799      * <em>asymmetrical</em>.  That is, in the following code:
800      *
801      * <pre>
802      * cal->setTime(date1, err);
803      * int m1 = cal->fieldDifference(date2, Calendar::MONTH, err);
804      * int d1 = cal->fieldDifference(date2, Calendar::DATE, err);
805      * cal->setTime(date2, err);
806      * int m2 = cal->fieldDifference(date1, Calendar::MONTH, err);
807      * int d2 = cal->fieldDifference(date1, Calendar::DATE, err);</pre>
808      *
809      * one might expect that <code>m1 == -m2 && d1 == -d2</code>.
810      * However, this is not generally the case, because of
811      * irregularities in the underlying calendar system (e.g., the
812      * Gregorian calendar has a varying number of days per month).
813      *
814      * @param when the date to compare this calendar's time to
815      * @param field the field in which to compute the result
816      * @param status  Output param set to success/failure code on exit. If any value
817      *                previously set in the time field is invalid, this will be set to
818      *                an error status.
819      * @return the difference, either positive or negative, between
820      * this calendar's time and <code>when</code>, in terms of
821      * <code>field</code>.
822      * @stable ICU 2.6.
823      */
824     virtual int32_t fieldDifference(UDate when, UCalendarDateFields field, UErrorCode& status);
825 
826     /**
827      * Sets the calendar's time zone to be the one passed in. The Calendar takes ownership
828      * of the TimeZone; the caller is no longer responsible for deleting it.  If the
829      * given time zone is nullptr, this function has no effect.
830      *
831      * @param value  The given time zone.
832      * @stable ICU 2.0
833      */
834     void adoptTimeZone(TimeZone* value);
835 
836     /**
837      * Sets the calendar's time zone to be the same as the one passed in. The TimeZone
838      * passed in is _not_ adopted; the client is still responsible for deleting it.
839      *
840      * @param zone  The given time zone.
841      * @stable ICU 2.0
842      */
843     void setTimeZone(const TimeZone& zone);
844 
845     /**
846      * Returns a reference to the time zone owned by this calendar. The returned reference
847      * is only valid until clients make another call to adoptTimeZone or setTimeZone,
848      * or this Calendar is destroyed.
849      *
850      * @return   The time zone object associated with this calendar.
851      * @stable ICU 2.0
852      */
853     const TimeZone& getTimeZone(void) const;
854 
855     /**
856      * Returns the time zone owned by this calendar. The caller owns the returned object
857      * and must delete it when done.  After this call, the new time zone associated
858      * with this Calendar is the default TimeZone as returned by TimeZone::createDefault().
859      *
860      * @return   The time zone object which was associated with this calendar.
861      * @stable ICU 2.0
862      */
863     TimeZone* orphanTimeZone(void);
864 
865     /**
866      * Queries if the current date for this Calendar is in Daylight Savings Time.
867      *
868      * @param status Fill-in parameter which receives the status of this operation.
869      * @return   True if the current date for this Calendar is in Daylight Savings Time,
870      *           false, otherwise.
871      * @stable ICU 2.0
872      */
873     virtual UBool inDaylightTime(UErrorCode& status) const;
874 
875     /**
876      * Specifies whether or not date/time interpretation is to be lenient. With lenient
877      * interpretation, a date such as "February 942, 1996" will be treated as being
878      * equivalent to the 941st day after February 1, 1996. With strict interpretation,
879      * such dates will cause an error when computing time from the time field values
880      * representing the dates.
881      *
882      * @param lenient  True specifies date/time interpretation to be lenient.
883      *
884      * @see            DateFormat#setLenient
885      * @stable ICU 2.0
886      */
887     void setLenient(UBool lenient);
888 
889     /**
890      * Tells whether date/time interpretation is to be lenient.
891      *
892      * @return   True tells that date/time interpretation is to be lenient.
893      * @stable ICU 2.0
894      */
895     UBool isLenient(void) const;
896 
897     /**
898      * Sets the behavior for handling wall time repeating multiple times
899      * at negative time zone offset transitions. For example, 1:30 AM on
900      * November 6, 2011 in US Eastern time (America/New_York) occurs twice;
901      * 1:30 AM EDT, then 1:30 AM EST one hour later. When <code>UCAL_WALLTIME_FIRST</code>
902      * is used, the wall time 1:30AM in this example will be interpreted as 1:30 AM EDT
903      * (first occurrence). When <code>UCAL_WALLTIME_LAST</code> is used, it will be
904      * interpreted as 1:30 AM EST (last occurrence). The default value is
905      * <code>UCAL_WALLTIME_LAST</code>.
906      * <p>
907      * <b>Note:</b>When <code>UCAL_WALLTIME_NEXT_VALID</code> is not a valid
908      * option for this. When the argument is neither <code>UCAL_WALLTIME_FIRST</code>
909      * nor <code>UCAL_WALLTIME_LAST</code>, this method has no effect and will keep
910      * the current setting.
911      *
912      * @param option the behavior for handling repeating wall time, either
913      * <code>UCAL_WALLTIME_FIRST</code> or <code>UCAL_WALLTIME_LAST</code>.
914      * @see #getRepeatedWallTimeOption
915      * @stable ICU 49
916      */
917     void setRepeatedWallTimeOption(UCalendarWallTimeOption option);
918 
919     /**
920      * Gets the behavior for handling wall time repeating multiple times
921      * at negative time zone offset transitions.
922      *
923      * @return the behavior for handling repeating wall time, either
924      * <code>UCAL_WALLTIME_FIRST</code> or <code>UCAL_WALLTIME_LAST</code>.
925      * @see #setRepeatedWallTimeOption
926      * @stable ICU 49
927      */
928     UCalendarWallTimeOption getRepeatedWallTimeOption(void) const;
929 
930     /**
931      * Sets the behavior for handling skipped wall time at positive time zone offset
932      * transitions. For example, 2:30 AM on March 13, 2011 in US Eastern time (America/New_York)
933      * does not exist because the wall time jump from 1:59 AM EST to 3:00 AM EDT. When
934      * <code>UCAL_WALLTIME_FIRST</code> is used, 2:30 AM is interpreted as 30 minutes before 3:00 AM
935      * EDT, therefore, it will be resolved as 1:30 AM EST. When <code>UCAL_WALLTIME_LAST</code>
936      * is used, 2:30 AM is interpreted as 31 minutes after 1:59 AM EST, therefore, it will be
937      * resolved as 3:30 AM EDT. When <code>UCAL_WALLTIME_NEXT_VALID</code> is used, 2:30 AM will
938      * be resolved as next valid wall time, that is 3:00 AM EDT. The default value is
939      * <code>UCAL_WALLTIME_LAST</code>.
940      * <p>
941      * <b>Note:</b>This option is effective only when this calendar is lenient.
942      * When the calendar is strict, such non-existing wall time will cause an error.
943      *
944      * @param option the behavior for handling skipped wall time at positive time zone
945      * offset transitions, one of <code>UCAL_WALLTIME_FIRST</code>, <code>UCAL_WALLTIME_LAST</code> and
946      * <code>UCAL_WALLTIME_NEXT_VALID</code>.
947      * @see #getSkippedWallTimeOption
948      *
949      * @stable ICU 49
950      */
951     void setSkippedWallTimeOption(UCalendarWallTimeOption option);
952 
953     /**
954      * Gets the behavior for handling skipped wall time at positive time zone offset
955      * transitions.
956      *
957      * @return the behavior for handling skipped wall time, one of
958      * <code>UCAL_WALLTIME_FIRST</code>, <code>UCAL_WALLTIME_LAST</code>
959      * and <code>UCAL_WALLTIME_NEXT_VALID</code>.
960      * @see #setSkippedWallTimeOption
961      * @stable ICU 49
962      */
963     UCalendarWallTimeOption getSkippedWallTimeOption(void) const;
964 
965     /**
966      * Sets what the first day of the week is; e.g., Sunday in US, Monday in France.
967      *
968      * @param value  The given first day of the week.
969      * @stable ICU 2.6.
970      */
971     void setFirstDayOfWeek(UCalendarDaysOfWeek value);
972 
973 #ifndef U_HIDE_DEPRECATED_API
974     /**
975      * Gets what the first day of the week is; e.g., Sunday in US, Monday in France.
976      *
977      * @return   The first day of the week.
978      * @deprecated ICU 2.6 use the overload with error code
979      */
980     EDaysOfWeek getFirstDayOfWeek(void) const;
981 #endif  /* U_HIDE_DEPRECATED_API */
982 
983     /**
984      * Gets what the first day of the week is; e.g., Sunday in US, Monday in France.
985      *
986      * @param status error code
987      * @return   The first day of the week.
988      * @stable ICU 2.6
989      */
990     UCalendarDaysOfWeek getFirstDayOfWeek(UErrorCode &status) const;
991 
992     /**
993      * Sets what the minimal days required in the first week of the year are; For
994      * example, if the first week is defined as one that contains the first day of the
995      * first month of a year, call the method with value 1. If it must be a full week,
996      * use value 7.
997      *
998      * @param value  The given minimal days required in the first week of the year.
999      * @stable ICU 2.0
1000      */
1001     void setMinimalDaysInFirstWeek(uint8_t value);
1002 
1003     /**
1004      * Gets what the minimal days required in the first week of the year are; e.g., if
1005      * the first week is defined as one that contains the first day of the first month
1006      * of a year, getMinimalDaysInFirstWeek returns 1. If the minimal days required must
1007      * be a full week, getMinimalDaysInFirstWeek returns 7.
1008      *
1009      * @return   The minimal days required in the first week of the year.
1010      * @stable ICU 2.0
1011      */
1012     uint8_t getMinimalDaysInFirstWeek(void) const;
1013 
1014 #ifndef U_FORCE_HIDE_DEPRECATED_API
1015     /**
1016      * Gets the minimum value for the given time field. e.g., for Gregorian
1017      * DAY_OF_MONTH, 1.
1018      *
1019      * @param field  The given time field.
1020      * @return       The minimum value for the given time field.
1021      * @deprecated ICU 2.6. Use getMinimum(UCalendarDateFields field) instead.
1022      */
1023     virtual int32_t getMinimum(EDateFields field) const;
1024 #endif  // U_FORCE_HIDE_DEPRECATED_API
1025 
1026     /**
1027      * Gets the minimum value for the given time field. e.g., for Gregorian
1028      * DAY_OF_MONTH, 1.
1029      *
1030      * @param field  The given time field.
1031      * @return       The minimum value for the given time field.
1032      * @stable ICU 2.6.
1033      */
1034     virtual int32_t getMinimum(UCalendarDateFields field) const;
1035 
1036 #ifndef U_FORCE_HIDE_DEPRECATED_API
1037     /**
1038      * Gets the maximum value for the given time field. e.g. for Gregorian DAY_OF_MONTH,
1039      * 31.
1040      *
1041      * @param field  The given time field.
1042      * @return       The maximum value for the given time field.
1043      * @deprecated ICU 2.6. Use getMaximum(UCalendarDateFields field) instead.
1044      */
1045     virtual int32_t getMaximum(EDateFields field) const;
1046 #endif  // U_FORCE_HIDE_DEPRECATED_API
1047 
1048     /**
1049      * Gets the maximum value for the given time field. e.g. for Gregorian DAY_OF_MONTH,
1050      * 31.
1051      *
1052      * @param field  The given time field.
1053      * @return       The maximum value for the given time field.
1054      * @stable ICU 2.6.
1055      */
1056     virtual int32_t getMaximum(UCalendarDateFields field) const;
1057 
1058 #ifndef U_FORCE_HIDE_DEPRECATED_API
1059     /**
1060      * Gets the highest minimum value for the given field if varies. Otherwise same as
1061      * getMinimum(). For Gregorian, no difference.
1062      *
1063      * @param field  The given time field.
1064      * @return       The highest minimum value for the given time field.
1065      * @deprecated ICU 2.6. Use getGreatestMinimum(UCalendarDateFields field) instead.
1066      */
1067     virtual int32_t getGreatestMinimum(EDateFields field) const;
1068 #endif  // U_FORCE_HIDE_DEPRECATED_API
1069 
1070     /**
1071      * Gets the highest minimum value for the given field if varies. Otherwise same as
1072      * getMinimum(). For Gregorian, no difference.
1073      *
1074      * @param field  The given time field.
1075      * @return       The highest minimum value for the given time field.
1076      * @stable ICU 2.6.
1077      */
1078     virtual int32_t getGreatestMinimum(UCalendarDateFields field) const;
1079 
1080 #ifndef U_FORCE_HIDE_DEPRECATED_API
1081     /**
1082      * Gets the lowest maximum value for the given field if varies. Otherwise same as
1083      * getMaximum(). e.g., for Gregorian DAY_OF_MONTH, 28.
1084      *
1085      * @param field  The given time field.
1086      * @return       The lowest maximum value for the given time field.
1087      * @deprecated ICU 2.6. Use getLeastMaximum(UCalendarDateFields field) instead.
1088      */
1089     virtual int32_t getLeastMaximum(EDateFields field) const;
1090 #endif  // U_FORCE_HIDE_DEPRECATED_API
1091 
1092     /**
1093      * Gets the lowest maximum value for the given field if varies. Otherwise same as
1094      * getMaximum(). e.g., for Gregorian DAY_OF_MONTH, 28.
1095      *
1096      * @param field  The given time field.
1097      * @return       The lowest maximum value for the given time field.
1098      * @stable ICU 2.6.
1099      */
1100     virtual int32_t getLeastMaximum(UCalendarDateFields field) const;
1101 
1102 #ifndef U_HIDE_DEPRECATED_API
1103     /**
1104      * Return the minimum value that this field could have, given the current date.
1105      * For the Gregorian calendar, this is the same as getMinimum() and getGreatestMinimum().
1106      *
1107      * The version of this function on Calendar uses an iterative algorithm to determine the
1108      * actual minimum value for the field.  There is almost always a more efficient way to
1109      * accomplish this (in most cases, you can simply return getMinimum()).  GregorianCalendar
1110      * overrides this function with a more efficient implementation.
1111      *
1112      * @param field    the field to determine the minimum of
1113      * @param status   Fill-in parameter which receives the status of this operation.
1114      * @return         the minimum of the given field for the current date of this Calendar
1115      * @deprecated ICU 2.6. Use getActualMinimum(UCalendarDateFields field, UErrorCode& status) instead.
1116      */
1117     int32_t getActualMinimum(EDateFields field, UErrorCode& status) const;
1118 #endif  /* U_HIDE_DEPRECATED_API */
1119 
1120     /**
1121      * Return the minimum value that this field could have, given the current date.
1122      * For the Gregorian calendar, this is the same as getMinimum() and getGreatestMinimum().
1123      *
1124      * The version of this function on Calendar uses an iterative algorithm to determine the
1125      * actual minimum value for the field.  There is almost always a more efficient way to
1126      * accomplish this (in most cases, you can simply return getMinimum()).  GregorianCalendar
1127      * overrides this function with a more efficient implementation.
1128      *
1129      * @param field    the field to determine the minimum of
1130      * @param status   Fill-in parameter which receives the status of this operation.
1131      * @return         the minimum of the given field for the current date of this Calendar
1132      * @stable ICU 2.6.
1133      */
1134     virtual int32_t getActualMinimum(UCalendarDateFields field, UErrorCode& status) const;
1135 
1136     /**
1137      * Return the maximum value that this field could have, given the current date.
1138      * For example, with the date "Feb 3, 1997" and the DAY_OF_MONTH field, the actual
1139      * maximum would be 28; for "Feb 3, 1996" it s 29.  Similarly for a Hebrew calendar,
1140      * for some years the actual maximum for MONTH is 12, and for others 13.
1141      *
1142      * The version of this function on Calendar uses an iterative algorithm to determine the
1143      * actual maximum value for the field.  There is almost always a more efficient way to
1144      * accomplish this (in most cases, you can simply return getMaximum()).  GregorianCalendar
1145      * overrides this function with a more efficient implementation.
1146      *
1147      * @param field    the field to determine the maximum of
1148      * @param status   Fill-in parameter which receives the status of this operation.
1149      * @return         the maximum of the given field for the current date of this Calendar
1150      * @stable ICU 2.6.
1151      */
1152     virtual int32_t getActualMaximum(UCalendarDateFields field, UErrorCode& status) const;
1153 
1154     /**
1155      * Gets the value for a given time field. Recalculate the current time field values
1156      * if the time value has been changed by a call to setTime(). Return zero for unset
1157      * fields if any fields have been explicitly set by a call to set(). To force a
1158      * recomputation of all fields regardless of the previous state, call complete().
1159      * This method is semantically const, but may alter the object in memory.
1160      *
1161      * @param field  The given time field.
1162      * @param status Fill-in parameter which receives the status of the operation.
1163      * @return       The value for the given time field, or zero if the field is unset,
1164      *               and set() has been called for any other field.
1165      * @stable ICU 2.6.
1166      */
1167     int32_t get(UCalendarDateFields field, UErrorCode& status) const;
1168 
1169     /**
1170      * Determines if the given time field has a value set. This can affect in the
1171      * resolving of time in Calendar. Unset fields have a value of zero, by definition.
1172      *
1173      * @param field  The given time field.
1174      * @return   True if the given time field has a value set; false otherwise.
1175      * @stable ICU 2.6.
1176      */
1177     UBool isSet(UCalendarDateFields field) const;
1178 
1179     /**
1180      * Sets the given time field with the given value.
1181      *
1182      * @param field  The given time field.
1183      * @param value  The value to be set for the given time field.
1184      * @stable ICU 2.6.
1185      */
1186     void set(UCalendarDateFields field, int32_t value);
1187 
1188     /**
1189      * Sets the values for the fields YEAR, MONTH, and DATE. Other field values are
1190      * retained; call clear() first if this is not desired.
1191      *
1192      * @param year   The value used to set the YEAR time field.
1193      * @param month  The value used to set the MONTH time field. Month value is 0-based.
1194      *               e.g., 0 for January.
1195      * @param date   The value used to set the DATE time field.
1196      * @stable ICU 2.0
1197      */
1198     void set(int32_t year, int32_t month, int32_t date);
1199 
1200     /**
1201      * Sets the values for the fields YEAR, MONTH, DATE, HOUR_OF_DAY, and MINUTE. Other
1202      * field values are retained; call clear() first if this is not desired.
1203      *
1204      * @param year    The value used to set the YEAR time field.
1205      * @param month   The value used to set the MONTH time field. Month value is
1206      *                0-based. E.g., 0 for January.
1207      * @param date    The value used to set the DATE time field.
1208      * @param hour    The value used to set the HOUR_OF_DAY time field.
1209      * @param minute  The value used to set the MINUTE time field.
1210      * @stable ICU 2.0
1211      */
1212     void set(int32_t year, int32_t month, int32_t date, int32_t hour, int32_t minute);
1213 
1214     /**
1215      * Sets the values for the fields YEAR, MONTH, DATE, HOUR_OF_DAY, MINUTE, and SECOND.
1216      * Other field values are retained; call clear() first if this is not desired.
1217      *
1218      * @param year    The value used to set the YEAR time field.
1219      * @param month   The value used to set the MONTH time field. Month value is
1220      *                0-based. E.g., 0 for January.
1221      * @param date    The value used to set the DATE time field.
1222      * @param hour    The value used to set the HOUR_OF_DAY time field.
1223      * @param minute  The value used to set the MINUTE time field.
1224      * @param second  The value used to set the SECOND time field.
1225      * @stable ICU 2.0
1226      */
1227     void set(int32_t year, int32_t month, int32_t date, int32_t hour, int32_t minute, int32_t second);
1228 
1229     /**
1230      * Clears the values of all the time fields, making them both unset and assigning
1231      * them a value of zero. The field values will be determined during the next
1232      * resolving of time into time fields.
1233      * @stable ICU 2.0
1234      */
1235     void clear(void);
1236 
1237     /**
1238      * Clears the value in the given time field, both making it unset and assigning it a
1239      * value of zero. This field value will be determined during the next resolving of
1240      * time into time fields. Clearing UCAL_ORDINAL_MONTH or UCAL_MONTH will
1241      * clear both fields.
1242      *
1243      * @param field  The time field to be cleared.
1244      * @stable ICU 2.6.
1245      */
1246     void clear(UCalendarDateFields field);
1247 
1248     /**
1249      * Returns a unique class ID POLYMORPHICALLY. Pure virtual method. This method is to
1250      * implement a simple version of RTTI, since not all C++ compilers support genuine
1251      * RTTI. Polymorphic operator==() and clone() methods call this method.
1252      * <P>
1253      * Concrete subclasses of Calendar must implement getDynamicClassID() and also a
1254      * static method and data member:
1255      *
1256      *      static UClassID getStaticClassID() { return (UClassID)&amp;fgClassID; }
1257      *      static char fgClassID;
1258      *
1259      * @return   The class ID for this object. All objects of a given class have the
1260      *           same class ID. Objects of other classes have different class IDs.
1261      * @stable ICU 2.0
1262      */
1263     virtual UClassID getDynamicClassID(void) const override = 0;
1264 
1265     /**
1266      * Returns the calendar type name string for this Calendar object.
1267      * The returned string is the legacy ICU calendar attribute value,
1268      * for example, "gregorian" or "japanese".
1269      *
1270      * See type="old type name" for the calendar attribute of locale IDs
1271      * at http://www.unicode.org/reports/tr35/#Key_Type_Definitions
1272      *
1273      * Sample code for getting the LDML/BCP 47 calendar key value:
1274      * \code
1275      * const char *calType = cal->getType();
1276      * if (0 == strcmp(calType, "unknown")) {
1277      *     // deal with unknown calendar type
1278      * } else {
1279      *     string localeID("root@calendar=");
1280      *     localeID.append(calType);
1281      *     char langTag[100];
1282      *     UErrorCode errorCode = U_ZERO_ERROR;
1283      *     int32_t length = uloc_toLanguageTag(localeID.c_str(), langTag, (int32_t)sizeof(langTag), true, &errorCode);
1284      *     if (U_FAILURE(errorCode)) {
1285      *         // deal with errors & overflow
1286      *     }
1287      *     string lang(langTag, length);
1288      *     size_t caPos = lang.find("-ca-");
1289      *     lang.erase(0, caPos + 4);
1290      *     // lang now contains the LDML calendar type
1291      * }
1292      * \endcode
1293      *
1294      * @return legacy calendar type name string
1295      * @stable ICU 49
1296      */
1297     virtual const char * getType() const = 0;
1298 
1299     /**
1300      * Returns whether the given day of the week is a weekday, a weekend day,
1301      * or a day that transitions from one to the other, for the locale and
1302      * calendar system associated with this Calendar (the locale's region is
1303      * often the most determinant factor). If a transition occurs at midnight,
1304      * then the days before and after the transition will have the
1305      * type UCAL_WEEKDAY or UCAL_WEEKEND. If a transition occurs at a time
1306      * other than midnight, then the day of the transition will have
1307      * the type UCAL_WEEKEND_ONSET or UCAL_WEEKEND_CEASE. In this case, the
1308      * method getWeekendTransition() will return the point of
1309      * transition.
1310      * @param dayOfWeek The day of the week whose type is desired (UCAL_SUNDAY..UCAL_SATURDAY).
1311      * @param status The error code for the operation.
1312      * @return The UCalendarWeekdayType for the day of the week.
1313      * @stable ICU 4.4
1314      */
1315     virtual UCalendarWeekdayType getDayOfWeekType(UCalendarDaysOfWeek dayOfWeek, UErrorCode &status) const;
1316 
1317     /**
1318      * Returns the time during the day at which the weekend begins or ends in
1319      * this calendar system.  If getDayOfWeekType() returns UCAL_WEEKEND_ONSET
1320      * for the specified dayOfWeek, return the time at which the weekend begins.
1321      * If getDayOfWeekType() returns UCAL_WEEKEND_CEASE for the specified dayOfWeek,
1322      * return the time at which the weekend ends. If getDayOfWeekType() returns
1323      * some other UCalendarWeekdayType for the specified dayOfWeek, is it an error condition
1324      * (U_ILLEGAL_ARGUMENT_ERROR).
1325      * @param dayOfWeek The day of the week for which the weekend transition time is
1326      * desired (UCAL_SUNDAY..UCAL_SATURDAY).
1327      * @param status The error code for the operation.
1328      * @return The milliseconds after midnight at which the weekend begins or ends.
1329      * @stable ICU 4.4
1330      */
1331     virtual int32_t getWeekendTransition(UCalendarDaysOfWeek dayOfWeek, UErrorCode &status) const;
1332 
1333     /**
1334      * Returns true if the given UDate is in the weekend in
1335      * this calendar system.
1336      * @param date The UDate in question.
1337      * @param status The error code for the operation.
1338      * @return true if the given UDate is in the weekend in
1339      * this calendar system, false otherwise.
1340      * @stable ICU 4.4
1341      */
1342     virtual UBool isWeekend(UDate date, UErrorCode &status) const;
1343 
1344     /**
1345      * Returns true if this Calendar's current date-time is in the weekend in
1346      * this calendar system.
1347      * @return true if this Calendar's current date-time is in the weekend in
1348      * this calendar system, false otherwise.
1349      * @stable ICU 4.4
1350      */
1351     virtual UBool isWeekend(void) const;
1352 
1353 #ifndef U_FORCE_HIDE_DRAFT_API
1354     /**
1355      * Returns true if the date is in a leap year. Recalculate the current time
1356      * field values if the time value has been changed by a call to * setTime().
1357      * This method is semantically const, but may alter the object in memory.
1358      * A "leap year" is a year that contains more days than other years (for
1359      * solar or lunar calendars) or more months than other years (for lunisolar
1360      * calendars like Hebrew or Chinese), as defined in the ECMAScript Temporal
1361      * proposal.
1362      *
1363      * @param status        ICU Error Code
1364      * @return       True if the date in the fields is in a Temporal proposal
1365      *               defined leap year. False otherwise.
1366      * @draft ICU 73
1367      */
1368     virtual bool inTemporalLeapYear(UErrorCode& status) const;
1369 
1370     /**
1371      * Gets The Temporal monthCode value corresponding to the month for the date.
1372      * The value is a string identifier that starts with the literal grapheme
1373      * "M" followed by two graphemes representing the zero-padded month number
1374      * of the current month in a normal (non-leap) year and suffixed by an
1375      * optional literal grapheme "L" if this is a leap month in a lunisolar
1376      * calendar. The 25 possible values are "M01" .. "M13" and "M01L" .. "M12L".
1377      * For the Hebrew calendar, the values are "M01" .. "M12" for non-leap year, and
1378      * "M01" .. "M05", "M05L", "M06" .. "M12" for leap year.
1379      * For the Chinese calendar, the values are "M01" .. "M12" for non-leap year and
1380      * in leap year with another monthCode in "M01L" .. "M12L".
1381      * For Coptic and Ethiopian calendar, the Temporal monthCode values for any
1382      * years are "M01" to "M13".
1383      *
1384      * @param status        ICU Error Code
1385      * @return       One of 25 possible strings in {"M01".."M13", "M01L".."M12L"}.
1386      * @draft ICU 73
1387      */
1388     virtual const char* getTemporalMonthCode(UErrorCode& status) const;
1389 
1390     /**
1391      * Sets The Temporal monthCode which is a string identifier that starts
1392      * with the literal grapheme "M" followed by two graphemes representing
1393      * the zero-padded month number of the current month in a normal
1394      * (non-leap) year and suffixed by an optional literal grapheme "L" if this
1395      * is a leap month in a lunisolar calendar. The 25 possible values are
1396      * "M01" .. "M13" and "M01L" .. "M12L". For Hebrew calendar, the values are
1397      * "M01" .. "M12" for non-leap years, and "M01" .. "M05", "M05L", "M06"
1398      * .. "M12" for leap year.
1399      * For the Chinese calendar, the values are "M01" .. "M12" for non-leap year and
1400      * in leap year with another monthCode in "M01L" .. "M12L".
1401      * For Coptic and Ethiopian calendar, the Temporal monthCode values for any
1402      * years are "M01" to "M13".
1403      *
1404      * @param temporalMonth  The value to be set for temporal monthCode.
1405      * @param status        ICU Error Code
1406      *
1407      * @draft ICU 73
1408      */
1409     virtual void setTemporalMonthCode(const char* temporalMonth, UErrorCode& status);
1410 
1411 #endif  // U_FORCE_HIDE_DRAFT_API
1412 
1413 protected:
1414 
1415      /**
1416       * Constructs a Calendar with the default time zone as returned by
1417       * TimeZone::createInstance(), and the default locale.
1418       *
1419       * @param success  Indicates the status of Calendar object construction. Returns
1420       *                 U_ZERO_ERROR if constructed successfully.
1421      * @stable ICU 2.0
1422       */
1423     Calendar(UErrorCode& success);
1424 
1425     /**
1426      * Copy constructor
1427      *
1428      * @param source    Calendar object to be copied from
1429      * @stable ICU 2.0
1430      */
1431     Calendar(const Calendar& source);
1432 
1433     /**
1434      * Default assignment operator
1435      *
1436      * @param right    Calendar object to be copied
1437      * @stable ICU 2.0
1438      */
1439     Calendar& operator=(const Calendar& right);
1440 
1441     /**
1442      * Constructs a Calendar with the given time zone and locale. Clients are no longer
1443      * responsible for deleting the given time zone object after it's adopted.
1444      *
1445      * @param zone     The given time zone.
1446      * @param aLocale  The given locale.
1447      * @param success  Indicates the status of Calendar object construction. Returns
1448      *                 U_ZERO_ERROR if constructed successfully.
1449      * @stable ICU 2.0
1450      */
1451     Calendar(TimeZone* zone, const Locale& aLocale, UErrorCode& success);
1452 
1453     /**
1454      * Constructs a Calendar with the given time zone and locale.
1455      *
1456      * @param zone     The given time zone.
1457      * @param aLocale  The given locale.
1458      * @param success  Indicates the status of Calendar object construction. Returns
1459      *                 U_ZERO_ERROR if constructed successfully.
1460      * @stable ICU 2.0
1461      */
1462     Calendar(const TimeZone& zone, const Locale& aLocale, UErrorCode& success);
1463 
1464     /**
1465      * Converts Calendar's time field values to GMT as milliseconds.
1466      *
1467      * @param status  Output param set to success/failure code on exit. If any value
1468      *                previously set in the time field is invalid or restricted by
1469      *                leniency, this will be set to an error status.
1470      * @stable ICU 2.0
1471      */
1472     virtual void computeTime(UErrorCode& status);
1473 
1474     /**
1475      * Converts GMT as milliseconds to time field values. This allows you to sync up the
1476      * time field values with a new time that is set for the calendar.  This method
1477      * does NOT recompute the time first; to recompute the time, then the fields, use
1478      * the method complete().
1479      *
1480      * @param status  Output param set to success/failure code on exit. If any value
1481      *                previously set in the time field is invalid or restricted by
1482      *                leniency, this will be set to an error status.
1483      * @stable ICU 2.0
1484      */
1485     virtual void computeFields(UErrorCode& status);
1486 
1487     /**
1488      * Gets this Calendar's current time as a long.
1489      *
1490      * @param status  Output param set to success/failure code on exit. If any value
1491      *                previously set in the time field is invalid or restricted by
1492      *                leniency, this will be set to an error status.
1493      * @return the current time as UTC milliseconds from the epoch.
1494      * @stable ICU 2.0
1495      */
1496     double getTimeInMillis(UErrorCode& status) const;
1497 
1498     /**
1499      * Sets this Calendar's current time from the given long value.
1500      * @param millis  the new time in UTC milliseconds from the epoch.
1501      * @param status  Output param set to success/failure code on exit. If any value
1502      *                previously set in the time field is invalid or restricted by
1503      *                leniency, this will be set to an error status.
1504      * @stable ICU 2.0
1505      */
1506     void setTimeInMillis( double millis, UErrorCode& status );
1507 
1508     /**
1509      * Recomputes the current time from currently set fields, and then fills in any
1510      * unset fields in the time field list.
1511      *
1512      * @param status  Output param set to success/failure code on exit. If any value
1513      *                previously set in the time field is invalid or restricted by
1514      *                leniency, this will be set to an error status.
1515      * @stable ICU 2.0
1516      */
1517     void complete(UErrorCode& status);
1518 
1519 #ifndef U_HIDE_DEPRECATED_API
1520     /**
1521      * Gets the value for a given time field. Subclasses can use this function to get
1522      * field values without forcing recomputation of time.
1523      *
1524      * @param field  The given time field.
1525      * @return       The value for the given time field.
1526      * @deprecated ICU 2.6. Use internalGet(UCalendarDateFields field) instead.
1527      */
internalGet(EDateFields field)1528     inline int32_t internalGet(EDateFields field) const {return fFields[field];}
1529 #endif  /* U_HIDE_DEPRECATED_API */
1530 
1531 #ifndef U_HIDE_INTERNAL_API
1532     /**
1533      * Gets the value for a given time field. Subclasses can use this function to get
1534      * field values without forcing recomputation of time. If the field's stamp is UNSET,
1535      * the defaultValue is used.
1536      *
1537      * @param field  The given time field.
1538      * @param defaultValue a default value used if the field is unset.
1539      * @return       The value for the given time field.
1540      * @internal
1541      */
internalGet(UCalendarDateFields field,int32_t defaultValue)1542     inline int32_t internalGet(UCalendarDateFields field, int32_t defaultValue) const {return fStamp[field]>kUnset ? fFields[field] : defaultValue;}
1543 
1544     /**
1545      * Gets the value for a given time field. Subclasses can use this function to get
1546      * field values without forcing recomputation of time.
1547      *
1548      * @param field  The given time field.
1549      * @return       The value for the given time field.
1550      * @internal
1551      */
internalGet(UCalendarDateFields field)1552     inline int32_t internalGet(UCalendarDateFields field) const {return fFields[field];}
1553 #endif  /* U_HIDE_INTERNAL_API */
1554 
1555     /**
1556      * Use this function instead of internalGet(UCAL_MONTH). The implementation
1557      * check the timestamp of UCAL_MONTH and UCAL_ORDINAL_MONTH and use the
1558      * one set later. The subclass should override it to conver the value of UCAL_ORDINAL_MONTH
1559      * to UCAL_MONTH correctly if UCAL_ORDINAL_MONTH has higher priority.
1560      *
1561      * @return       The value for the UCAL_MONTH.
1562      * @internal
1563      */
1564     virtual int32_t internalGetMonth() const;
1565 
1566     /**
1567      * Use this function instead of internalGet(UCAL_MONTH, defaultValue). The implementation
1568      * check the timestamp of UCAL_MONTH and UCAL_ORDINAL_MONTH and use the
1569      * one set later. The subclass should override it to conver the value of UCAL_ORDINAL_MONTH
1570      * to UCAL_MONTH correctly if UCAL_ORDINAL_MONTH has higher priority.
1571      *
1572      * @param defaultValue a default value used if the UCAL_MONTH and
1573      *   UCAL_ORDINAL are both unset.
1574      * @return       The value for the UCAL_MONTH.
1575      * @internal
1576      */
1577     virtual int32_t internalGetMonth(int32_t defaultValue) const;
1578 
1579 #ifndef U_HIDE_DEPRECATED_API
1580     /**
1581      * Sets the value for a given time field.  This is a fast internal method for
1582      * subclasses.  It does not affect the areFieldsInSync, isTimeSet, or areAllFieldsSet
1583      * flags.
1584      *
1585      * @param field    The given time field.
1586      * @param value    The value for the given time field.
1587      * @deprecated ICU 2.6. Use internalSet(UCalendarDateFields field, int32_t value) instead.
1588      */
1589     void internalSet(EDateFields field, int32_t value);
1590 #endif  /* U_HIDE_DEPRECATED_API */
1591 
1592     /**
1593      * Sets the value for a given time field.  This is a fast internal method for
1594      * subclasses.  It does not affect the areFieldsInSync, isTimeSet, or areAllFieldsSet
1595      * flags.
1596      *
1597      * @param field    The given time field.
1598      * @param value    The value for the given time field.
1599      * @stable ICU 2.6.
1600      */
1601     inline void internalSet(UCalendarDateFields field, int32_t value);
1602 
1603     /**
1604      * Prepare this calendar for computing the actual minimum or maximum.
1605      * This method modifies this calendar's fields; it is called on a
1606      * temporary calendar.
1607      * @internal
1608      */
1609     virtual void prepareGetActual(UCalendarDateFields field, UBool isMinimum, UErrorCode &status);
1610 
1611     /**
1612      * Limit enums. Not in sync with UCalendarLimitType (refers to internal fields).
1613      * @internal
1614      */
1615     enum ELimitType {
1616 #ifndef U_HIDE_INTERNAL_API
1617       UCAL_LIMIT_MINIMUM = 0,
1618       UCAL_LIMIT_GREATEST_MINIMUM,
1619       UCAL_LIMIT_LEAST_MAXIMUM,
1620       UCAL_LIMIT_MAXIMUM,
1621       UCAL_LIMIT_COUNT
1622 #endif  /* U_HIDE_INTERNAL_API */
1623     };
1624 
1625     /**
1626      * Subclass API for defining limits of different types.
1627      * Subclasses must implement this method to return limits for the
1628      * following fields:
1629      *
1630      * <pre>UCAL_ERA
1631      * UCAL_YEAR
1632      * UCAL_MONTH
1633      * UCAL_WEEK_OF_YEAR
1634      * UCAL_WEEK_OF_MONTH
1635      * UCAL_DATE (DAY_OF_MONTH on Java)
1636      * UCAL_DAY_OF_YEAR
1637      * UCAL_DAY_OF_WEEK_IN_MONTH
1638      * UCAL_YEAR_WOY
1639      * UCAL_EXTENDED_YEAR</pre>
1640      *
1641      * @param field one of the above field numbers
1642      * @param limitType one of <code>MINIMUM</code>, <code>GREATEST_MINIMUM</code>,
1643      * <code>LEAST_MAXIMUM</code>, or <code>MAXIMUM</code>
1644      * @internal
1645      */
1646     virtual int32_t handleGetLimit(UCalendarDateFields field, ELimitType limitType) const = 0;
1647 
1648     /**
1649      * Return a limit for a field.
1650      * @param field the field, from <code>0..UCAL_MAX_FIELD</code>
1651      * @param limitType the type specifier for the limit
1652      * @see #ELimitType
1653      * @internal
1654      */
1655     virtual int32_t getLimit(UCalendarDateFields field, ELimitType limitType) const;
1656 
1657     /**
1658      * Return the Julian day number of day before the first day of the
1659      * given month in the given extended year.  Subclasses should override
1660      * this method to implement their calendar system.
1661      * @param eyear the extended year
1662      * @param month the zero-based month, or 0 if useMonth is false
1663      * @param useMonth if false, compute the day before the first day of
1664      * the given year, otherwise, compute the day before the first day of
1665      * the given month
1666      * @return the Julian day number of the day before the first
1667      * day of the given month and year
1668      * @internal
1669      */
1670     virtual int32_t handleComputeMonthStart(int32_t eyear, int32_t month,
1671                                                    UBool useMonth) const  = 0;
1672 
1673     /**
1674      * Return the number of days in the given month of the given extended
1675      * year of this calendar system.  Subclasses should override this
1676      * method if they can provide a more correct or more efficient
1677      * implementation than the default implementation in Calendar.
1678      * @internal
1679      */
1680     virtual int32_t handleGetMonthLength(int32_t extendedYear, int32_t month) const ;
1681 
1682     /**
1683      * Return the number of days in the given extended year of this
1684      * calendar system.  Subclasses should override this method if they can
1685      * provide a more correct or more efficient implementation than the
1686      * default implementation in Calendar.
1687      * @stable ICU 2.0
1688      */
1689     virtual int32_t handleGetYearLength(int32_t eyear) const;
1690 
1691 
1692     /**
1693      * Return the extended year defined by the current fields.  This will
1694      * use the UCAL_EXTENDED_YEAR field or the UCAL_YEAR and supra-year fields (such
1695      * as UCAL_ERA) specific to the calendar system, depending on which set of
1696      * fields is newer.
1697      * @return the extended year
1698      * @internal
1699      */
1700     virtual int32_t handleGetExtendedYear() = 0;
1701 
1702     /**
1703      * Subclasses may override this.  This method calls
1704      * handleGetMonthLength() to obtain the calendar-specific month
1705      * length.
1706      * @param bestField which field to use to calculate the date
1707      * @return julian day specified by calendar fields.
1708      * @internal
1709      */
1710     virtual int32_t handleComputeJulianDay(UCalendarDateFields bestField);
1711 
1712     /**
1713      * Subclasses must override this to convert from week fields
1714      * (YEAR_WOY and WEEK_OF_YEAR) to an extended year in the case
1715      * where YEAR, EXTENDED_YEAR are not set.
1716      * The Calendar implementation assumes yearWoy is in extended gregorian form
1717      * @return the extended year, UCAL_EXTENDED_YEAR
1718      * @internal
1719      */
1720     virtual int32_t handleGetExtendedYearFromWeekFields(int32_t yearWoy, int32_t woy);
1721 
1722     /**
1723      * Validate a single field of this calendar.  Subclasses should
1724      * override this method to validate any calendar-specific fields.
1725      * Generic fields can be handled by `Calendar::validateField()`.
1726      * @internal
1727      */
1728     virtual void validateField(UCalendarDateFields field, UErrorCode &status);
1729 
1730 #ifndef U_HIDE_INTERNAL_API
1731     /**
1732      * Compute the Julian day from fields.  Will determine whether to use
1733      * the JULIAN_DAY field directly, or other fields.
1734      * @return the julian day
1735      * @internal
1736      */
1737     int32_t computeJulianDay();
1738 
1739     /**
1740      * Compute the milliseconds in the day from the fields.  This is a
1741      * value from 0 to 23:59:59.999 inclusive, unless fields are out of
1742      * range, in which case it can be an arbitrary value.  This value
1743      * reflects local zone wall time.
1744      * @internal
1745      */
1746     double computeMillisInDay();
1747 
1748     /**
1749      * This method can assume EXTENDED_YEAR has been set.
1750      * @param millis milliseconds of the date fields
1751      * @param millisInDay milliseconds of the time fields; may be out
1752      * or range.
1753      * @param ec Output param set to failure code on function return
1754      *          when this function fails.
1755      * @internal
1756      */
1757     int32_t computeZoneOffset(double millis, double millisInDay, UErrorCode &ec);
1758 
1759 
1760     /**
1761      * Determine the best stamp in a range.
1762      * @param start first enum to look at
1763      * @param end last enum to look at
1764      * @param bestSoFar stamp prior to function call
1765      * @return the stamp value of the best stamp
1766      * @internal
1767      */
1768     int32_t newestStamp(UCalendarDateFields start, UCalendarDateFields end, int32_t bestSoFar) const;
1769 
1770     /**
1771      * Marker for end of resolve set (row or group). Value for field resolution tables.
1772      *
1773      * @see #resolveFields
1774      * @internal
1775      */
1776     static constexpr int32_t kResolveSTOP = -1;
1777     /**
1778      * Value to be bitwised "ORed" against resolve table field values for remapping.
1779      * Example: (UCAL_DATE | kResolveRemap) in 1st column will cause 'UCAL_DATE' to be returned,
1780      * but will not examine the value of UCAL_DATE.
1781      * Value for field resolution tables.
1782      *
1783      * @see #resolveFields
1784      * @internal
1785      */
1786     static constexpr int32_t kResolveRemap = 32;
1787 
1788     /**
1789      * Precedence table for Dates
1790      * @see #resolveFields
1791      * @internal
1792      */
1793     static const UFieldResolutionTable kDatePrecedence[];
1794 
1795     /**
1796      * Precedence table for Year
1797      * @see #resolveFields
1798      * @internal
1799      */
1800     static const UFieldResolutionTable kYearPrecedence[];
1801 
1802     /**
1803      * Precedence table for Day of Week
1804      * @see #resolveFields
1805      * @internal
1806      */
1807     static const UFieldResolutionTable kDOWPrecedence[];
1808 
1809     /**
1810      * Precedence table for Months
1811      * @see #resolveFields
1812      * @internal
1813      */
1814     static const UFieldResolutionTable kMonthPrecedence[];
1815 
1816     /**
1817      * Given a precedence table, return the newest field combination in
1818      * the table, or UCAL_FIELD_COUNT if none is found.
1819      *
1820      * <p>The precedence table is a 3-dimensional array of integers.  It
1821      * may be thought of as an array of groups.  Each group is an array of
1822      * lines.  Each line is an array of field numbers.  Within a line, if
1823      * all fields are set, then the time stamp of the line is taken to be
1824      * the stamp of the most recently set field.  If any field of a line is
1825      * unset, then the line fails to match.  Within a group, the line with
1826      * the newest time stamp is selected.  The first field of the line is
1827      * returned to indicate which line matched.
1828      *
1829      * <p>In some cases, it may be desirable to map a line to field that
1830      * whose stamp is NOT examined.  For example, if the best field is
1831      * DAY_OF_WEEK then the DAY_OF_WEEK_IN_MONTH algorithm may be used.  In
1832      * order to do this, insert the value <code>kResolveRemap | F</code> at
1833      * the start of the line, where <code>F</code> is the desired return
1834      * field value.  This field will NOT be examined; it only determines
1835      * the return value if the other fields in the line are the newest.
1836      *
1837      * <p>If all lines of a group contain at least one unset field, then no
1838      * line will match, and the group as a whole will fail to match.  In
1839      * that case, the next group will be processed.  If all groups fail to
1840      * match, then UCAL_FIELD_COUNT is returned.
1841      * @internal
1842      */
1843     UCalendarDateFields resolveFields(const UFieldResolutionTable *precedenceTable) const;
1844 #endif  /* U_HIDE_INTERNAL_API */
1845 
1846 
1847     /**
1848      * @internal
1849      */
1850     virtual const UFieldResolutionTable* getFieldResolutionTable() const;
1851 
1852 #ifndef U_HIDE_INTERNAL_API
1853     /**
1854      * Return the field that is newer, either defaultField, or
1855      * alternateField.  If neither is newer or neither is set, return defaultField.
1856      * @internal
1857      */
1858     UCalendarDateFields newerField(UCalendarDateFields defaultField, UCalendarDateFields alternateField) const;
1859 #endif  /* U_HIDE_INTERNAL_API */
1860 
1861 
1862 private:
1863     /**
1864      * Helper function for calculating limits by trial and error
1865      * @param field The field being investigated
1866      * @param startValue starting (least max) value of field
1867      * @param endValue ending (greatest max) value of field
1868      * @param status return type
1869      * @internal (private)
1870      */
1871     int32_t getActualHelper(UCalendarDateFields field, int32_t startValue, int32_t endValue, UErrorCode &status) const;
1872 
1873 
1874 protected:
1875     /**
1876      * The flag which indicates if the current time is set in the calendar.
1877      * @stable ICU 2.0
1878      */
1879     UBool      fIsTimeSet;
1880 
1881     /**
1882      * True if the fields are in sync with the currently set time of this Calendar.
1883      * If false, then the next attempt to get the value of a field will
1884      * force a recomputation of all fields from the current value of the time
1885      * field.
1886      * <P>
1887      * This should really be named areFieldsInSync, but the old name is retained
1888      * for backward compatibility.
1889      * @stable ICU 2.0
1890      */
1891     UBool      fAreFieldsSet;
1892 
1893     /**
1894      * True if all of the fields have been set.  This is initially false, and set to
1895      * true by computeFields().
1896      * @stable ICU 2.0
1897      */
1898     UBool      fAreAllFieldsSet;
1899 
1900     /**
1901      * True if all fields have been virtually set, but have not yet been
1902      * computed.  This occurs only in setTimeInMillis().  A calendar set
1903      * to this state will compute all fields from the time if it becomes
1904      * necessary, but otherwise will delay such computation.
1905      * @stable ICU 3.0
1906      */
1907     UBool fAreFieldsVirtuallySet;
1908 
1909     /**
1910      * Get the current time without recomputing.
1911      *
1912      * @return     the current time without recomputing.
1913      * @stable ICU 2.0
1914      */
internalGetTime(void)1915     UDate        internalGetTime(void) const     { return fTime; }
1916 
1917     /**
1918      * Set the current time without affecting flags or fields.
1919      *
1920      * @param time    The time to be set
1921      * @return        the current time without recomputing.
1922      * @stable ICU 2.0
1923      */
internalSetTime(UDate time)1924     void        internalSetTime(UDate time)     { fTime = time; }
1925 
1926     /**
1927      * The time fields containing values into which the millis is computed.
1928      * @stable ICU 2.0
1929      */
1930     int32_t     fFields[UCAL_FIELD_COUNT];
1931 
1932 #ifndef U_FORCE_HIDE_DEPRECATED_API
1933     /**
1934      * The flags which tell if a specified time field for the calendar is set.
1935      * @deprecated ICU 2.8 use (fStamp[n]!=kUnset)
1936      */
1937     UBool      fIsSet[UCAL_FIELD_COUNT];
1938 #endif  // U_FORCE_HIDE_DEPRECATED_API
1939 
1940     /** Special values of stamp[]
1941      * @stable ICU 2.0
1942      */
1943     enum {
1944         kUnset                 = 0,
1945         kInternallySet,
1946         kMinimumUserStamp
1947     };
1948 
1949     /**
1950      * Pseudo-time-stamps which specify when each field was set. There
1951      * are two special values, UNSET and INTERNALLY_SET. Values from
1952      * MINIMUM_USER_SET to Integer.MAX_VALUE are legal user set values.
1953      * @stable ICU 2.0
1954      */
1955     int32_t        fStamp[UCAL_FIELD_COUNT];
1956 
1957     /**
1958      * Subclasses may override this method to compute several fields
1959      * specific to each calendar system.  These are:
1960      *
1961      * <ul><li>ERA
1962      * <li>YEAR
1963      * <li>MONTH
1964      * <li>DAY_OF_MONTH
1965      * <li>DAY_OF_YEAR
1966      * <li>EXTENDED_YEAR</ul>
1967      *
1968      * Subclasses can refer to the DAY_OF_WEEK and DOW_LOCAL fields, which
1969      * will be set when this method is called.  Subclasses can also call
1970      * the getGregorianXxx() methods to obtain Gregorian calendar
1971      * equivalents for the given Julian day.
1972      *
1973      * <p>In addition, subclasses should compute any subclass-specific
1974      * fields, that is, fields from BASE_FIELD_COUNT to
1975      * getFieldCount() - 1.
1976      *
1977      * <p>The default implementation in <code>Calendar</code> implements
1978      * a pure proleptic Gregorian calendar.
1979      * @internal
1980      */
1981     virtual void handleComputeFields(int32_t julianDay, UErrorCode &status);
1982 
1983 #ifndef U_HIDE_INTERNAL_API
1984     /**
1985      * Return the extended year on the Gregorian calendar as computed by
1986      * <code>computeGregorianFields()</code>.
1987      * @internal
1988      */
getGregorianYear()1989     int32_t getGregorianYear() const {
1990         return fGregorianYear;
1991     }
1992 
1993     /**
1994      * Return the month (0-based) on the Gregorian calendar as computed by
1995      * <code>computeGregorianFields()</code>.
1996      * @internal
1997      */
getGregorianMonth()1998     int32_t getGregorianMonth() const {
1999         return fGregorianMonth;
2000     }
2001 
2002     /**
2003      * Return the day of year (1-based) on the Gregorian calendar as
2004      * computed by <code>computeGregorianFields()</code>.
2005      * @internal
2006      */
getGregorianDayOfYear()2007     int32_t getGregorianDayOfYear() const {
2008         return fGregorianDayOfYear;
2009     }
2010 
2011     /**
2012      * Return the day of month (1-based) on the Gregorian calendar as
2013      * computed by <code>computeGregorianFields()</code>.
2014      * @internal
2015      */
getGregorianDayOfMonth()2016     int32_t getGregorianDayOfMonth() const {
2017       return fGregorianDayOfMonth;
2018     }
2019 #endif  /* U_HIDE_INTERNAL_API */
2020 
2021     /**
2022      * Called by computeJulianDay.  Returns the default month (0-based) for the year,
2023      * taking year and era into account.  Defaults to 0 for Gregorian, which doesn't care.
2024      * @param eyear The extended year
2025      * @internal
2026      */
2027     virtual int32_t getDefaultMonthInYear(int32_t eyear) ;
2028 
2029 
2030     /**
2031      * Called by computeJulianDay.  Returns the default day (1-based) for the month,
2032      * taking currently-set year and era into account.  Defaults to 1 for Gregorian.
2033      * @param eyear the extended year
2034      * @param month the month in the year
2035      * @internal
2036      */
2037     virtual int32_t getDefaultDayInMonth(int32_t eyear, int32_t month);
2038 
2039     //-------------------------------------------------------------------------
2040     // Protected utility methods for use by subclasses.  These are very handy
2041     // for implementing add, roll, and computeFields.
2042     //-------------------------------------------------------------------------
2043 
2044     /**
2045      * Adjust the specified field so that it is within
2046      * the allowable range for the date to which this calendar is set.
2047      * For example, in a Gregorian calendar pinning the {@link #UCalendarDateFields DAY_OF_MONTH}
2048      * field for a calendar set to April 31 would cause it to be set
2049      * to April 30.
2050      * <p>
2051      * <b>Subclassing:</b>
2052      * <br>
2053      * This utility method is intended for use by subclasses that need to implement
2054      * their own overrides of {@link #roll roll} and {@link #add add}.
2055      * <p>
2056      * <b>Note:</b>
2057      * <code>pinField</code> is implemented in terms of
2058      * {@link #getActualMinimum getActualMinimum}
2059      * and {@link #getActualMaximum getActualMaximum}.  If either of those methods uses
2060      * a slow, iterative algorithm for a particular field, it would be
2061      * unwise to attempt to call <code>pinField</code> for that field.  If you
2062      * really do need to do so, you should override this method to do
2063      * something more efficient for that field.
2064      * <p>
2065      * @param field The calendar field whose value should be pinned.
2066      * @param status Output param set to failure code on function return
2067      *          when this function fails.
2068      *
2069      * @see #getActualMinimum
2070      * @see #getActualMaximum
2071      * @stable ICU 2.0
2072      */
2073     virtual void pinField(UCalendarDateFields field, UErrorCode& status);
2074 
2075     /**
2076      * Return the week number of a day, within a period. This may be the week number in
2077      * a year or the week number in a month. Usually this will be a value >= 1, but if
2078      * some initial days of the period are excluded from week 1, because
2079      * {@link #getMinimalDaysInFirstWeek getMinimalDaysInFirstWeek} is > 1, then
2080      * the week number will be zero for those
2081      * initial days. This method requires the day number and day of week for some
2082      * known date in the period in order to determine the day of week
2083      * on the desired day.
2084      * <p>
2085      * <b>Subclassing:</b>
2086      * <br>
2087      * This method is intended for use by subclasses in implementing their
2088      * {@link #computeTime computeTime} and/or {@link #computeFields computeFields} methods.
2089      * It is often useful in {@link #getActualMinimum getActualMinimum} and
2090      * {@link #getActualMaximum getActualMaximum} as well.
2091      * <p>
2092      * This variant is handy for computing the week number of some other
2093      * day of a period (often the first or last day of the period) when its day
2094      * of the week is not known but the day number and day of week for some other
2095      * day in the period (e.g. the current date) <em>is</em> known.
2096      * <p>
2097      * @param desiredDay    The {@link #UCalendarDateFields DAY_OF_YEAR} or
2098      *              {@link #UCalendarDateFields DAY_OF_MONTH} whose week number is desired.
2099      *              Should be 1 for the first day of the period.
2100      *
2101      * @param dayOfPeriod   The {@link #UCalendarDateFields DAY_OF_YEAR}
2102      *              or {@link #UCalendarDateFields DAY_OF_MONTH} for a day in the period whose
2103      *              {@link #UCalendarDateFields DAY_OF_WEEK} is specified by the
2104      *              <code>knownDayOfWeek</code> parameter.
2105      *              Should be 1 for first day of period.
2106      *
2107      * @param dayOfWeek  The {@link #UCalendarDateFields DAY_OF_WEEK} for the day
2108      *              corresponding to the <code>knownDayOfPeriod</code> parameter.
2109      *              1-based with 1=Sunday.
2110      *
2111      * @return      The week number (one-based), or zero if the day falls before
2112      *              the first week because
2113      *              {@link #getMinimalDaysInFirstWeek getMinimalDaysInFirstWeek}
2114      *              is more than one.
2115      *
2116      * @stable ICU 2.8
2117      */
2118     int32_t weekNumber(int32_t desiredDay, int32_t dayOfPeriod, int32_t dayOfWeek);
2119 
2120 
2121 #ifndef U_HIDE_INTERNAL_API
2122     /**
2123      * Return the week number of a day, within a period. This may be the week number in
2124      * a year, or the week number in a month. Usually this will be a value >= 1, but if
2125      * some initial days of the period are excluded from week 1, because
2126      * {@link #getMinimalDaysInFirstWeek getMinimalDaysInFirstWeek} is > 1,
2127      * then the week number will be zero for those
2128      * initial days. This method requires the day of week for the given date in order to
2129      * determine the result.
2130      * <p>
2131      * <b>Subclassing:</b>
2132      * <br>
2133      * This method is intended for use by subclasses in implementing their
2134      * {@link #computeTime computeTime} and/or {@link #computeFields computeFields} methods.
2135      * It is often useful in {@link #getActualMinimum getActualMinimum} and
2136      * {@link #getActualMaximum getActualMaximum} as well.
2137      * <p>
2138      * @param dayOfPeriod   The {@link #UCalendarDateFields DAY_OF_YEAR} or
2139      *                      {@link #UCalendarDateFields DAY_OF_MONTH} whose week number is desired.
2140      *                      Should be 1 for the first day of the period.
2141      *
2142      * @param dayOfWeek     The {@link #UCalendarDateFields DAY_OF_WEEK} for the day
2143      *                      corresponding to the <code>dayOfPeriod</code> parameter.
2144      *                      1-based with 1=Sunday.
2145      *
2146      * @return      The week number (one-based), or zero if the day falls before
2147      *              the first week because
2148      *              {@link #getMinimalDaysInFirstWeek getMinimalDaysInFirstWeek}
2149      *              is more than one.
2150      * @internal
2151      */
2152     inline int32_t weekNumber(int32_t dayOfPeriod, int32_t dayOfWeek);
2153 
2154     /**
2155      * returns the local DOW, valid range 0..6
2156      * @internal
2157      */
2158     int32_t getLocalDOW();
2159 #endif  /* U_HIDE_INTERNAL_API */
2160 
2161 private:
2162 
2163     /**
2164      * The next available value for fStamp[]
2165      */
2166     int32_t fNextStamp;// = MINIMUM_USER_STAMP;
2167 
2168     /**
2169      * Recalculates the time stamp array (fStamp).
2170      * Resets fNextStamp to lowest next stamp value.
2171      */
2172     void recalculateStamp();
2173 
2174     /**
2175      * The current time set for the calendar.
2176      */
2177     UDate        fTime;
2178 
2179     /**
2180      * @see   #setLenient
2181      */
2182     UBool      fLenient;
2183 
2184     /**
2185      * Time zone affects the time calculation done by Calendar. Calendar subclasses use
2186      * the time zone data to produce the local time. Always set; never nullptr.
2187      */
2188     TimeZone*   fZone;
2189 
2190     /**
2191      * Option for repeated wall time
2192      * @see #setRepeatedWallTimeOption
2193      */
2194     UCalendarWallTimeOption fRepeatedWallTime;
2195 
2196     /**
2197      * Option for skipped wall time
2198      * @see #setSkippedWallTimeOption
2199      */
2200     UCalendarWallTimeOption fSkippedWallTime;
2201 
2202     /**
2203      * Both firstDayOfWeek and minimalDaysInFirstWeek are locale-dependent. They are
2204      * used to figure out the week count for a specific date for a given locale. These
2205      * must be set when a Calendar is constructed. For example, in US locale,
2206      * firstDayOfWeek is SUNDAY; minimalDaysInFirstWeek is 1. They are used to figure
2207      * out the week count for a specific date for a given locale. These must be set when
2208      * a Calendar is constructed.
2209      */
2210     UCalendarDaysOfWeek fFirstDayOfWeek;
2211     uint8_t     fMinimalDaysInFirstWeek;
2212     UCalendarDaysOfWeek fWeekendOnset;
2213     int32_t fWeekendOnsetMillis;
2214     UCalendarDaysOfWeek fWeekendCease;
2215     int32_t fWeekendCeaseMillis;
2216 
2217     /**
2218      * Sets firstDayOfWeek and minimalDaysInFirstWeek. Called at Calendar construction
2219      * time.
2220      *
2221      * @param desiredLocale  The given locale.
2222      * @param type           The calendar type identifier, e.g: gregorian, buddhist, etc.
2223      * @param success        Indicates the status of setting the week count data from
2224      *                       the resource for the given locale. Returns U_ZERO_ERROR if
2225      *                       constructed successfully.
2226      */
2227     void        setWeekData(const Locale& desiredLocale, const char *type, UErrorCode& success);
2228 
2229     /**
2230      * Recompute the time and update the status fields isTimeSet
2231      * and areFieldsSet.  Callers should check isTimeSet and only
2232      * call this method if isTimeSet is false.
2233      *
2234      * @param status  Output param set to success/failure code on exit. If any value
2235      *                previously set in the time field is invalid or restricted by
2236      *                leniency, this will be set to an error status.
2237      */
2238     void updateTime(UErrorCode& status);
2239 
2240     /**
2241      * The Gregorian year, as computed by computeGregorianFields() and
2242      * returned by getGregorianYear().
2243      * @see #computeGregorianFields
2244      */
2245     int32_t fGregorianYear;
2246 
2247     /**
2248      * The Gregorian month, as computed by computeGregorianFields() and
2249      * returned by getGregorianMonth().
2250      * @see #computeGregorianFields
2251      */
2252     int32_t fGregorianMonth;
2253 
2254     /**
2255      * The Gregorian day of the year, as computed by
2256      * computeGregorianFields() and returned by getGregorianDayOfYear().
2257      * @see #computeGregorianFields
2258      */
2259     int32_t fGregorianDayOfYear;
2260 
2261     /**
2262      * The Gregorian day of the month, as computed by
2263      * computeGregorianFields() and returned by getGregorianDayOfMonth().
2264      * @see #computeGregorianFields
2265      */
2266     int32_t fGregorianDayOfMonth;
2267 
2268     /* calculations */
2269 
2270     /**
2271      * Compute the Gregorian calendar year, month, and day of month from
2272      * the given Julian day.  These values are not stored in fields, but in
2273      * member variables gregorianXxx.  Also compute the DAY_OF_WEEK and
2274      * DOW_LOCAL fields.
2275      */
2276     void computeGregorianAndDOWFields(int32_t julianDay, UErrorCode &ec);
2277 
2278 protected:
2279 
2280     /**
2281      * Compute the Gregorian calendar year, month, and day of month from the
2282      * Julian day.  These values are not stored in fields, but in member
2283      * variables gregorianXxx.  They are used for time zone computations and by
2284      * subclasses that are Gregorian derivatives.  Subclasses may call this
2285      * method to perform a Gregorian calendar millis->fields computation.
2286      */
2287     void computeGregorianFields(int32_t julianDay, UErrorCode &ec);
2288 
2289 private:
2290 
2291     /**
2292      * Compute the fields WEEK_OF_YEAR, YEAR_WOY, WEEK_OF_MONTH,
2293      * DAY_OF_WEEK_IN_MONTH, and DOW_LOCAL from EXTENDED_YEAR, YEAR,
2294      * DAY_OF_WEEK, and DAY_OF_YEAR.  The latter fields are computed by the
2295      * subclass based on the calendar system.
2296      *
2297      * <p>The YEAR_WOY field is computed simplistically.  It is equal to YEAR
2298      * most of the time, but at the year boundary it may be adjusted to YEAR-1
2299      * or YEAR+1 to reflect the overlap of a week into an adjacent year.  In
2300      * this case, a simple increment or decrement is performed on YEAR, even
2301      * though this may yield an invalid YEAR value.  For instance, if the YEAR
2302      * is part of a calendar system with an N-year cycle field CYCLE, then
2303      * incrementing the YEAR may involve incrementing CYCLE and setting YEAR
2304      * back to 0 or 1.  This is not handled by this code, and in fact cannot be
2305      * simply handled without having subclasses define an entire parallel set of
2306      * fields for fields larger than or equal to a year.  This additional
2307      * complexity is not warranted, since the intention of the YEAR_WOY field is
2308      * to support ISO 8601 notation, so it will typically be used with a
2309      * proleptic Gregorian calendar, which has no field larger than a year.
2310      */
2311     void computeWeekFields(UErrorCode &ec);
2312 
2313 
2314     /**
2315      * Ensure that each field is within its valid range by calling {@link
2316      * #validateField(int, int&)} on each field that has been set.  This method
2317      * should only be called if this calendar is not lenient.
2318      * @see #isLenient
2319      * @see #validateField(int, int&)
2320      */
2321     void validateFields(UErrorCode &status);
2322 
2323     /**
2324      * Validate a single field of this calendar given its minimum and
2325      * maximum allowed value.  If the field is out of range,
2326      * <code>U_ILLEGAL_ARGUMENT_ERROR</code> will be set.  Subclasses may
2327      * use this method in their implementation of {@link
2328      * #validateField(int, int&)}.
2329      */
2330     void validateField(UCalendarDateFields field, int32_t min, int32_t max, UErrorCode& status);
2331 
2332  protected:
2333 #ifndef U_HIDE_INTERNAL_API
2334     /**
2335      * Convert a quasi Julian date to the day of the week. The Julian date used here is
2336      * not a true Julian date, since it is measured from midnight, not noon. Return
2337      * value is one-based.
2338      *
2339      * @param julian  The given Julian date number.
2340      * @return   Day number from 1..7 (SUN..SAT).
2341      * @internal
2342      */
2343     static uint8_t julianDayToDayOfWeek(double julian);
2344 #endif  /* U_HIDE_INTERNAL_API */
2345 
2346  private:
2347     char validLocale[ULOC_FULLNAME_CAPACITY];
2348     char actualLocale[ULOC_FULLNAME_CAPACITY];
2349 
2350  public:
2351 #if !UCONFIG_NO_SERVICE
2352     /**
2353      * INTERNAL FOR 2.6 --  Registration.
2354      */
2355 
2356 #ifndef U_HIDE_INTERNAL_API
2357     /**
2358      * Return a StringEnumeration over the locales available at the time of the call,
2359      * including registered locales.
2360      * @return a StringEnumeration over the locales available at the time of the call
2361      * @internal
2362      */
2363     static StringEnumeration* getAvailableLocales(void);
2364 
2365     /**
2366      * Register a new Calendar factory.  The factory will be adopted.
2367      * INTERNAL in 2.6
2368      *
2369      * Because ICU may choose to cache Calendars internally, this must
2370      * be called at application startup, prior to any calls to
2371      * Calendar::createInstance to avoid undefined behavior.
2372      *
2373      * @param toAdopt the factory instance to be adopted
2374      * @param status the in/out status code, no special meanings are assigned
2375      * @return a registry key that can be used to unregister this factory
2376      * @internal
2377      */
2378     static URegistryKey registerFactory(ICUServiceFactory* toAdopt, UErrorCode& status);
2379 
2380     /**
2381      * Unregister a previously-registered CalendarFactory using the key returned from the
2382      * register call.  Key becomes invalid after a successful call and should not be used again.
2383      * The CalendarFactory corresponding to the key will be deleted.
2384      * INTERNAL in 2.6
2385      *
2386      * Because ICU may choose to cache Calendars internally, this should
2387      * be called during application shutdown, after all calls to
2388      * Calendar::createInstance to avoid undefined behavior.
2389      *
2390      * @param key the registry key returned by a previous call to registerFactory
2391      * @param status the in/out status code, no special meanings are assigned
2392      * @return true if the factory for the key was successfully unregistered
2393      * @internal
2394      */
2395     static UBool unregister(URegistryKey key, UErrorCode& status);
2396 #endif  /* U_HIDE_INTERNAL_API */
2397 
2398     /**
2399      * Multiple Calendar Implementation
2400      * @internal
2401      */
2402     friend class CalendarFactory;
2403 
2404     /**
2405      * Multiple Calendar Implementation
2406      * @internal
2407      */
2408     friend class CalendarService;
2409 
2410     /**
2411      * Multiple Calendar Implementation
2412      * @internal
2413      */
2414     friend class DefaultCalendarFactory;
2415 #endif /* !UCONFIG_NO_SERVICE */
2416 
2417     /**
2418      * @return true if this calendar has a default century (i.e. 03 -> 2003)
2419      * @internal
2420      */
2421     virtual UBool haveDefaultCentury() const = 0;
2422 
2423     /**
2424      * @return the start of the default century, as a UDate
2425      * @internal
2426      */
2427     virtual UDate defaultCenturyStart() const = 0;
2428     /**
2429      * @return the beginning year of the default century, as a year
2430      * @internal
2431      */
2432     virtual int32_t defaultCenturyStartYear() const = 0;
2433 
2434     /** Get the locale for this calendar object. You can choose between valid and actual locale.
2435      *  @param type type of the locale we're looking for (valid or actual)
2436      *  @param status error code for the operation
2437      *  @return the locale
2438      *  @stable ICU 2.8
2439      */
2440     Locale getLocale(ULocDataLocaleType type, UErrorCode &status) const;
2441 
2442     /**
2443      * @return      The related Gregorian year; will be obtained by modifying the value
2444      *              obtained by get from UCAL_EXTENDED_YEAR field
2445      * @internal
2446      */
2447     virtual int32_t getRelatedYear(UErrorCode &status) const;
2448 
2449     /**
2450      * @param year  The related Gregorian year to set; will be modified as necessary then
2451      *              set in UCAL_EXTENDED_YEAR field
2452      * @internal
2453      */
2454     virtual void setRelatedYear(int32_t year);
2455 
2456 #ifndef U_HIDE_INTERNAL_API
2457     /** Get the locale for this calendar object. You can choose between valid and actual locale.
2458      *  @param type type of the locale we're looking for (valid or actual)
2459      *  @param status error code for the operation
2460      *  @return the locale
2461      *  @internal
2462      */
2463     const char* getLocaleID(ULocDataLocaleType type, UErrorCode &status) const;
2464 #endif  /* U_HIDE_INTERNAL_API */
2465 
2466 private:
2467     /**
2468      * Cast TimeZone used by this object to BasicTimeZone, or nullptr if the TimeZone
2469      * is not an instance of BasicTimeZone.
2470      */
2471     BasicTimeZone* getBasicTimeZone() const;
2472 
2473     /**
2474      * Find the previous zone transition near the given time.
2475      * @param base The base time, inclusive
2476      * @param transitionTime Receives the result time
2477      * @param status The error status
2478      * @return true if a transition is found.
2479      */
2480     UBool getImmediatePreviousZoneTransition(UDate base, UDate *transitionTime, UErrorCode& status) const;
2481 
2482 public:
2483 #ifndef U_HIDE_INTERNAL_API
2484     /**
2485      * Creates a new Calendar from a Locale for the cache.
2486      * This method does not set the time or timezone in returned calendar.
2487      * @param locale the locale.
2488      * @param status any error returned here.
2489      * @return the new Calendar object with no time or timezone set.
2490      * @internal For ICU use only.
2491      */
2492     static Calendar * U_EXPORT2 makeInstance(
2493             const Locale &locale, UErrorCode &status);
2494 
2495     /**
2496      * Get the calendar type for given locale.
2497      * @param locale the locale
2498      * @param typeBuffer calendar type returned here
2499      * @param typeBufferSize The size of typeBuffer in bytes. If the type
2500      *   can't fit in the buffer, this method sets status to
2501      *   U_BUFFER_OVERFLOW_ERROR
2502      * @param status error, if any, returned here.
2503      * @internal For ICU use only.
2504      */
2505     static void U_EXPORT2 getCalendarTypeFromLocale(
2506             const Locale &locale,
2507             char *typeBuffer,
2508             int32_t typeBufferSize,
2509             UErrorCode &status);
2510 #endif  /* U_HIDE_INTERNAL_API */
2511 };
2512 
2513 // -------------------------------------
2514 
2515 inline Calendar*
createInstance(TimeZone * zone,UErrorCode & errorCode)2516 Calendar::createInstance(TimeZone* zone, UErrorCode& errorCode)
2517 {
2518     // since the Locale isn't specified, use the default locale
2519     return createInstance(zone, Locale::getDefault(), errorCode);
2520 }
2521 
2522 // -------------------------------------
2523 
2524 inline void
roll(UCalendarDateFields field,UBool up,UErrorCode & status)2525 Calendar::roll(UCalendarDateFields field, UBool up, UErrorCode& status)
2526 {
2527     roll(field, (int32_t)(up ? +1 : -1), status);
2528 }
2529 
2530 #ifndef U_HIDE_DEPRECATED_API
2531 inline void
roll(EDateFields field,UBool up,UErrorCode & status)2532 Calendar::roll(EDateFields field, UBool up, UErrorCode& status)
2533 {
2534     roll((UCalendarDateFields) field, up, status);
2535 }
2536 #endif  /* U_HIDE_DEPRECATED_API */
2537 
2538 
2539 // -------------------------------------
2540 
2541 /**
2542  * Fast method for subclasses.  The caller must maintain fUserSetDSTOffset and
2543  * fUserSetZoneOffset, as well as the isSet[] array.
2544  */
2545 
2546 inline void
internalSet(UCalendarDateFields field,int32_t value)2547 Calendar::internalSet(UCalendarDateFields field, int32_t value)
2548 {
2549     fFields[field] = value;
2550     fStamp[field] = kInternallySet;
2551     fIsSet[field]     = true; // Remove later
2552 }
2553 
2554 
2555 #ifndef U_HIDE_INTERNAL_API
weekNumber(int32_t dayOfPeriod,int32_t dayOfWeek)2556 inline int32_t  Calendar::weekNumber(int32_t dayOfPeriod, int32_t dayOfWeek)
2557 {
2558   return weekNumber(dayOfPeriod, dayOfPeriod, dayOfWeek);
2559 }
2560 #endif  /* U_HIDE_INTERNAL_API */
2561 
2562 U_NAMESPACE_END
2563 
2564 #endif /* #if !UCONFIG_NO_FORMATTING */
2565 
2566 #endif /* U_SHOW_CPLUSPLUS_API */
2567 
2568 #endif // _CALENDAR
2569