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