1 /*************************************************************************
2 * Copyright (c) 1997-2013, International Business Machines Corporation
3 * and others. All Rights Reserved.
4 **************************************************************************
5 *
6 * File TIMEZONE.H
7 *
8 * Modification History:
9 *
10 * Date Name Description
11 * 04/21/97 aliu Overhauled header.
12 * 07/09/97 helena Changed createInstance to createDefault.
13 * 08/06/97 aliu Removed dependency on internal header for Hashtable.
14 * 08/10/98 stephen Changed getDisplayName() API conventions to match
15 * 08/19/98 stephen Changed createTimeZone() to never return 0
16 * 09/02/98 stephen Sync to JDK 1.2 8/31
17 * - Added getOffset(... monthlen ...)
18 * - Added hasSameRules()
19 * 09/15/98 stephen Added getStaticClassID
20 * 12/03/99 aliu Moved data out of static table into icudata.dll.
21 * Hashtable replaced by new static data structures.
22 * 12/14/99 aliu Made GMT public.
23 * 08/15/01 grhoten Made GMT private and added the getGMT() function
24 **************************************************************************
25 */
26
27 #ifndef TIMEZONE_H
28 #define TIMEZONE_H
29
30 #include "unicode/utypes.h"
31
32 /**
33 * \file
34 * \brief C++ API: TimeZone object
35 */
36
37 #if !UCONFIG_NO_FORMATTING
38
39 #include "unicode/uobject.h"
40 #include "unicode/unistr.h"
41 #include "unicode/ures.h"
42 #include "unicode/ucal.h"
43
44 U_NAMESPACE_BEGIN
45
46 class StringEnumeration;
47
48 /**
49 *
50 * <code>TimeZone</code> represents a time zone offset, and also figures out daylight
51 * savings.
52 *
53 * <p>
54 * Typically, you get a <code>TimeZone</code> using <code>createDefault</code>
55 * which creates a <code>TimeZone</code> based on the time zone where the program
56 * is running. For example, for a program running in Japan, <code>createDefault</code>
57 * creates a <code>TimeZone</code> object based on Japanese Standard Time.
58 *
59 * <p>
60 * You can also get a <code>TimeZone</code> using <code>createTimeZone</code> along
61 * with a time zone ID. For instance, the time zone ID for the US Pacific
62 * Time zone is "America/Los_Angeles". So, you can get a Pacific Time <code>TimeZone</code> object
63 * with:
64 * \htmlonly<blockquote>\endhtmlonly
65 * <pre>
66 * TimeZone *tz = TimeZone::createTimeZone("America/Los_Angeles");
67 * </pre>
68 * \htmlonly</blockquote>\endhtmlonly
69 * You can use <code>getAvailableIDs</code> method to iterate through
70 * all the supported time zone IDs, or getCanonicalID method to check
71 * if a time zone ID is supported or not. You can then choose a
72 * supported ID to get a <code>TimeZone</code>.
73 * If the time zone you want is not represented by one of the
74 * supported IDs, then you can create a custom time zone ID with
75 * the following syntax:
76 *
77 * \htmlonly<blockquote>\endhtmlonly
78 * <pre>
79 * GMT[+|-]hh[[:]mm]
80 * </pre>
81 * \htmlonly</blockquote>\endhtmlonly
82 *
83 * For example, you might specify GMT+14:00 as a custom
84 * time zone ID. The <code>TimeZone</code> that is returned
85 * when you specify a custom time zone ID uses the specified
86 * offset from GMT(=UTC) and does not observe daylight saving
87 * time. For example, you might specify GMT+14:00 as a custom
88 * time zone ID to create a TimeZone representing 14 hours ahead
89 * of GMT (with no daylight saving time). In addition,
90 * <code>getCanonicalID</code> can also be used to
91 * normalize a custom time zone ID.
92 *
93 * TimeZone is an abstract class representing a time zone. A TimeZone is needed for
94 * Calendar to produce local time for a particular time zone. A TimeZone comprises
95 * three basic pieces of information:
96 * <ul>
97 * <li>A time zone offset; that, is the number of milliseconds to add or subtract
98 * from a time expressed in terms of GMT to convert it to the same time in that
99 * time zone (without taking daylight savings time into account).</li>
100 * <li>Logic necessary to take daylight savings time into account if daylight savings
101 * time is observed in that time zone (e.g., the days and hours on which daylight
102 * savings time begins and ends).</li>
103 * <li>An ID. This is a text string that uniquely identifies the time zone.</li>
104 * </ul>
105 *
106 * (Only the ID is actually implemented in TimeZone; subclasses of TimeZone may handle
107 * daylight savings time and GMT offset in different ways. Currently we have the following
108 * TimeZone subclasses: RuleBasedTimeZone, SimpleTimeZone, and VTimeZone.)
109 * <P>
110 * The TimeZone class contains a static list containing a TimeZone object for every
111 * combination of GMT offset and daylight-savings time rules currently in use in the
112 * world, each with a unique ID. Each ID consists of a region (usually a continent or
113 * ocean) and a city in that region, separated by a slash, (for example, US Pacific
114 * Time is "America/Los_Angeles.") Because older versions of this class used
115 * three- or four-letter abbreviations instead, there is also a table that maps the older
116 * abbreviations to the newer ones (for example, "PST" maps to "America/Los_Angeles").
117 * Anywhere the API requires an ID, you can use either form.
118 * <P>
119 * To create a new TimeZone, you call the factory function TimeZone::createTimeZone()
120 * and pass it a time zone ID. You can use the createEnumeration() function to
121 * obtain a list of all the time zone IDs recognized by createTimeZone().
122 * <P>
123 * You can also use TimeZone::createDefault() to create a TimeZone. This function uses
124 * platform-specific APIs to produce a TimeZone for the time zone corresponding to
125 * the client's computer's physical location. For example, if you're in Japan (assuming
126 * your machine is set up correctly), TimeZone::createDefault() will return a TimeZone
127 * for Japanese Standard Time ("Asia/Tokyo").
128 */
129 class U_I18N_API TimeZone : public UObject {
130 public:
131 /**
132 * @stable ICU 2.0
133 */
134 virtual ~TimeZone();
135
136 /**
137 * Returns the "unknown" time zone.
138 * It behaves like the GMT/UTC time zone but has the
139 * <code>UCAL_UNKNOWN_ZONE_ID</code> = "Etc/Unknown".
140 * createTimeZone() returns a mutable clone of this time zone if the input ID is not recognized.
141 *
142 * @return the "unknown" time zone.
143 * @see UCAL_UNKNOWN_ZONE_ID
144 * @see createTimeZone
145 * @see getGMT
146 * @stable ICU 49
147 */
148 static const TimeZone& U_EXPORT2 getUnknown();
149
150 /**
151 * The GMT (=UTC) time zone has a raw offset of zero and does not use daylight
152 * savings time. This is a commonly used time zone.
153 *
154 * <p>Note: For backward compatibility reason, the ID used by the time
155 * zone returned by this method is "GMT", although the ICU's canonical
156 * ID for the GMT time zone is "Etc/GMT".
157 *
158 * @return the GMT/UTC time zone.
159 * @see getUnknown
160 * @stable ICU 2.0
161 */
162 static const TimeZone* U_EXPORT2 getGMT(void);
163
164 /**
165 * Creates a <code>TimeZone</code> for the given ID.
166 * @param ID the ID for a <code>TimeZone</code>, such as "America/Los_Angeles",
167 * or a custom ID such as "GMT-8:00".
168 * @return the specified <code>TimeZone</code>, or a mutable clone of getUnknown()
169 * if the given ID cannot be understood or if the given ID is "Etc/Unknown".
170 * The return result is guaranteed to be non-NULL.
171 * If you require that the specific zone asked for be returned,
172 * compare the result with getUnknown() or check the ID of the return result.
173 * @stable ICU 2.0
174 */
175 static TimeZone* U_EXPORT2 createTimeZone(const UnicodeString& ID);
176
177 /**
178 * Returns an enumeration over system time zone IDs with the given
179 * filter conditions.
180 * @param zoneType The system time zone type.
181 * @param region The ISO 3166 two-letter country code or UN M.49
182 * three-digit area code. When NULL, no filtering
183 * done by region.
184 * @param rawOffset An offset from GMT in milliseconds, ignoring
185 * the effect of daylight savings time, if any.
186 * When NULL, no filtering done by zone offset.
187 * @param ec Output param to filled in with a success or
188 * an error.
189 * @return an enumeration object, owned by the caller.
190 * @stable ICU 4.8
191 */
192 static StringEnumeration* U_EXPORT2 createTimeZoneIDEnumeration(
193 USystemTimeZoneType zoneType,
194 const char* region,
195 const int32_t* rawOffset,
196 UErrorCode& ec);
197
198 /**
199 * Returns an enumeration over all recognized time zone IDs. (i.e.,
200 * all strings that createTimeZone() accepts)
201 *
202 * @return an enumeration object, owned by the caller.
203 * @stable ICU 2.4
204 */
205 static StringEnumeration* U_EXPORT2 createEnumeration();
206
207 /**
208 * Returns an enumeration over time zone IDs with a given raw
209 * offset from GMT. There may be several times zones with the
210 * same GMT offset that differ in the way they handle daylight
211 * savings time. For example, the state of Arizona doesn't
212 * observe daylight savings time. If you ask for the time zone
213 * IDs corresponding to GMT-7:00, you'll get back an enumeration
214 * over two time zone IDs: "America/Denver," which corresponds to
215 * Mountain Standard Time in the winter and Mountain Daylight Time
216 * in the summer, and "America/Phoenix", which corresponds to
217 * Mountain Standard Time year-round, even in the summer.
218 *
219 * @param rawOffset an offset from GMT in milliseconds, ignoring
220 * the effect of daylight savings time, if any
221 * @return an enumeration object, owned by the caller
222 * @stable ICU 2.4
223 */
224 static StringEnumeration* U_EXPORT2 createEnumeration(int32_t rawOffset);
225
226 /**
227 * Returns an enumeration over time zone IDs associated with the
228 * given country. Some zones are affiliated with no country
229 * (e.g., "UTC"); these may also be retrieved, as a group.
230 *
231 * @param country The ISO 3166 two-letter country code, or NULL to
232 * retrieve zones not affiliated with any country.
233 * @return an enumeration object, owned by the caller
234 * @stable ICU 2.4
235 */
236 static StringEnumeration* U_EXPORT2 createEnumeration(const char* country);
237
238 /**
239 * Returns the number of IDs in the equivalency group that
240 * includes the given ID. An equivalency group contains zones
241 * that have the same GMT offset and rules.
242 *
243 * <p>The returned count includes the given ID; it is always >= 1.
244 * The given ID must be a system time zone. If it is not, returns
245 * zero.
246 * @param id a system time zone ID
247 * @return the number of zones in the equivalency group containing
248 * 'id', or zero if 'id' is not a valid system ID
249 * @see #getEquivalentID
250 * @stable ICU 2.0
251 */
252 static int32_t U_EXPORT2 countEquivalentIDs(const UnicodeString& id);
253
254 /**
255 * Returns an ID in the equivalency group that
256 * includes the given ID. An equivalency group contains zones
257 * that have the same GMT offset and rules.
258 *
259 * <p>The given index must be in the range 0..n-1, where n is the
260 * value returned by <code>countEquivalentIDs(id)</code>. For
261 * some value of 'index', the returned value will be equal to the
262 * given id. If the given id is not a valid system time zone, or
263 * if 'index' is out of range, then returns an empty string.
264 * @param id a system time zone ID
265 * @param index a value from 0 to n-1, where n is the value
266 * returned by <code>countEquivalentIDs(id)</code>
267 * @return the ID of the index-th zone in the equivalency group
268 * containing 'id', or an empty string if 'id' is not a valid
269 * system ID or 'index' is out of range
270 * @see #countEquivalentIDs
271 * @stable ICU 2.0
272 */
273 static const UnicodeString U_EXPORT2 getEquivalentID(const UnicodeString& id,
274 int32_t index);
275
276 /**
277 * Creates a new copy of the default TimeZone for this host. Unless the default time
278 * zone has already been set using adoptDefault() or setDefault(), the default is
279 * determined by querying the system using methods in TPlatformUtilities. If the
280 * system routines fail, or if they specify a TimeZone or TimeZone offset which is not
281 * recognized, the TimeZone indicated by the ID kLastResortID is instantiated
282 * and made the default.
283 *
284 * @return A default TimeZone. Clients are responsible for deleting the time zone
285 * object returned.
286 * @stable ICU 2.0
287 */
288 static TimeZone* U_EXPORT2 createDefault(void);
289
290 /**
291 * Sets the default time zone (i.e., what's returned by createDefault()) to be the
292 * specified time zone. If NULL is specified for the time zone, the default time
293 * zone is set to the default host time zone. This call adopts the TimeZone object
294 * passed in; the client is no longer responsible for deleting it.
295 *
296 * <p>This function is not thread safe. It is an error for multiple threads
297 * to concurrently attempt to set the default time zone, or for any thread
298 * to attempt to reference the default zone while another thread is setting it.
299 *
300 * @param zone A pointer to the new TimeZone object to use as the default.
301 * @stable ICU 2.0
302 */
303 static void U_EXPORT2 adoptDefault(TimeZone* zone);
304
305 #ifndef U_HIDE_SYSTEM_API
306 /**
307 * Same as adoptDefault(), except that the TimeZone object passed in is NOT adopted;
308 * the caller remains responsible for deleting it.
309 *
310 * <p>See the thread safety note under adoptDefault().
311 *
312 * @param zone The given timezone.
313 * @system
314 * @stable ICU 2.0
315 */
316 static void U_EXPORT2 setDefault(const TimeZone& zone);
317 #endif /* U_HIDE_SYSTEM_API */
318
319 /**
320 * Returns the timezone data version currently used by ICU.
321 * @param status Output param to filled in with a success or an error.
322 * @return the version string, such as "2007f"
323 * @stable ICU 3.8
324 */
325 static const char* U_EXPORT2 getTZDataVersion(UErrorCode& status);
326
327 /**
328 * Returns the canonical system timezone ID or the normalized
329 * custom time zone ID for the given time zone ID.
330 * @param id The input time zone ID to be canonicalized.
331 * @param canonicalID Receives the canonical system time zone ID
332 * or the custom time zone ID in normalized format.
333 * @param status Recevies the status. When the given time zone ID
334 * is neither a known system time zone ID nor a
335 * valid custom time zone ID, U_ILLEGAL_ARGUMENT_ERROR
336 * is set.
337 * @return A reference to the result.
338 * @stable ICU 4.0
339 */
340 static UnicodeString& U_EXPORT2 getCanonicalID(const UnicodeString& id,
341 UnicodeString& canonicalID, UErrorCode& status);
342
343 /**
344 * Returns the canonical system time zone ID or the normalized
345 * custom time zone ID for the given time zone ID.
346 * @param id The input time zone ID to be canonicalized.
347 * @param canonicalID Receives the canonical system time zone ID
348 * or the custom time zone ID in normalized format.
349 * @param isSystemID Receives if the given ID is a known system
350 * time zone ID.
351 * @param status Recevies the status. When the given time zone ID
352 * is neither a known system time zone ID nor a
353 * valid custom time zone ID, U_ILLEGAL_ARGUMENT_ERROR
354 * is set.
355 * @return A reference to the result.
356 * @stable ICU 4.0
357 */
358 static UnicodeString& U_EXPORT2 getCanonicalID(const UnicodeString& id,
359 UnicodeString& canonicalID, UBool& isSystemID, UErrorCode& status);
360
361 #ifndef U_HIDE_DRAFT_API
362 /**
363 * Converts a system time zone ID to an equivalent Windows time zone ID. For example,
364 * Windows time zone ID "Pacific Standard Time" is returned for input "America/Los_Angeles".
365 *
366 * <p>There are system time zones that cannot be mapped to Windows zones. When the input
367 * system time zone ID is unknown or unmappable to a Windows time zone, then the result will be
368 * empty, but the operation itself remains successful (no error status set on return).
369 *
370 * <p>This implementation utilizes <a href="http://unicode.org/cldr/charts/supplemental/zone_tzid.html">
371 * Zone-Tzid mapping data</a>. The mapping data is updated time to time. To get the latest changes,
372 * please read the ICU user guide section <a href="http://userguide.icu-project.org/datetime/timezone#TOC-Updating-the-Time-Zone-Data">
373 * Updating the Time Zone Data</a>.
374 *
375 * @param id A system time zone ID.
376 * @param winid Receives a Windows time zone ID. When the input system time zone ID is unknown
377 * or unmappable to a Windows time zone ID, then an empty string is set on return.
378 * @param status Receives the status.
379 * @return A reference to the result (<code>winid</code>).
380 * @see getIDForWindowsID
381 *
382 * @draft ICU 52
383 */
384 static UnicodeString& U_EXPORT2 getWindowsID(const UnicodeString& id,
385 UnicodeString& winid, UErrorCode& status);
386
387 /**
388 * Converts a Windows time zone ID to an equivalent system time zone ID
389 * for a region. For example, system time zone ID "America/Los_Angeles" is returned
390 * for input Windows ID "Pacific Standard Time" and region "US" (or <code>null</code>),
391 * "America/Vancouver" is returned for the same Windows ID "Pacific Standard Time" and
392 * region "CA".
393 *
394 * <p>Not all Windows time zones can be mapped to system time zones. When the input
395 * Windows time zone ID is unknown or unmappable to a system time zone, then the result
396 * will be empty, but the operation itself remains successful (no error status set on return).
397 *
398 * <p>This implementation utilizes <a href="http://unicode.org/cldr/charts/supplemental/zone_tzid.html">
399 * Zone-Tzid mapping data</a>. The mapping data is updated time to time. To get the latest changes,
400 * please read the ICU user guide section <a href="http://userguide.icu-project.org/datetime/timezone#TOC-Updating-the-Time-Zone-Data">
401 * Updating the Time Zone Data</a>.
402 *
403 * @param winid A Windows time zone ID.
404 * @param region A null-terminated region code, or <code>NULL</code> if no regional preference.
405 * @param id Receives a system time zone ID. When the input Windows time zone ID is unknown
406 * or unmappable to a system time zone ID, then an empty string is set on return.
407 * @param status Receives the status.
408 * @return A reference to the result (<code>id</code>).
409 * @see getWindowsID
410 *
411 * @draft ICU 52
412 */
413 static UnicodeString& U_EXPORT2 getIDForWindowsID(const UnicodeString& winid, const char* region,
414 UnicodeString& id, UErrorCode& status);
415
416 #endif /* U_HIDE_DRAFT_API */
417
418 /**
419 * Returns true if the two TimeZones are equal. (The TimeZone version only compares
420 * IDs, but subclasses are expected to also compare the fields they add.)
421 *
422 * @param that The TimeZone object to be compared with.
423 * @return True if the given TimeZone is equal to this TimeZone; false
424 * otherwise.
425 * @stable ICU 2.0
426 */
427 virtual UBool operator==(const TimeZone& that) const;
428
429 /**
430 * Returns true if the two TimeZones are NOT equal; that is, if operator==() returns
431 * false.
432 *
433 * @param that The TimeZone object to be compared with.
434 * @return True if the given TimeZone is not equal to this TimeZone; false
435 * otherwise.
436 * @stable ICU 2.0
437 */
438 UBool operator!=(const TimeZone& that) const {return !operator==(that);}
439
440 /**
441 * Returns the TimeZone's adjusted GMT offset (i.e., the number of milliseconds to add
442 * to GMT to get local time in this time zone, taking daylight savings time into
443 * account) as of a particular reference date. The reference date is used to determine
444 * whether daylight savings time is in effect and needs to be figured into the offset
445 * that is returned (in other words, what is the adjusted GMT offset in this time zone
446 * at this particular date and time?). For the time zones produced by createTimeZone(),
447 * the reference data is specified according to the Gregorian calendar, and the date
448 * and time fields are local standard time.
449 *
450 * <p>Note: Don't call this method. Instead, call the getOffset(UDate...) overload,
451 * which returns both the raw and the DST offset for a given time. This method
452 * is retained only for backward compatibility.
453 *
454 * @param era The reference date's era
455 * @param year The reference date's year
456 * @param month The reference date's month (0-based; 0 is January)
457 * @param day The reference date's day-in-month (1-based)
458 * @param dayOfWeek The reference date's day-of-week (1-based; 1 is Sunday)
459 * @param millis The reference date's milliseconds in day, local standard time
460 * @param status Output param to filled in with a success or an error.
461 * @return The offset in milliseconds to add to GMT to get local time.
462 * @stable ICU 2.0
463 */
464 virtual int32_t getOffset(uint8_t era, int32_t year, int32_t month, int32_t day,
465 uint8_t dayOfWeek, int32_t millis, UErrorCode& status) const = 0;
466
467 /**
468 * Gets the time zone offset, for current date, modified in case of
469 * daylight savings. This is the offset to add *to* UTC to get local time.
470 *
471 * <p>Note: Don't call this method. Instead, call the getOffset(UDate...) overload,
472 * which returns both the raw and the DST offset for a given time. This method
473 * is retained only for backward compatibility.
474 *
475 * @param era the era of the given date.
476 * @param year the year in the given date.
477 * @param month the month in the given date.
478 * Month is 0-based. e.g., 0 for January.
479 * @param day the day-in-month of the given date.
480 * @param dayOfWeek the day-of-week of the given date.
481 * @param milliseconds the millis in day in <em>standard</em> local time.
482 * @param monthLength the length of the given month in days.
483 * @param status Output param to filled in with a success or an error.
484 * @return the offset to add *to* GMT to get local time.
485 * @stable ICU 2.0
486 */
487 virtual int32_t getOffset(uint8_t era, int32_t year, int32_t month, int32_t day,
488 uint8_t dayOfWeek, int32_t milliseconds,
489 int32_t monthLength, UErrorCode& status) const = 0;
490
491 /**
492 * Returns the time zone raw and GMT offset for the given moment
493 * in time. Upon return, local-millis = GMT-millis + rawOffset +
494 * dstOffset. All computations are performed in the proleptic
495 * Gregorian calendar. The default implementation in the TimeZone
496 * class delegates to the 8-argument getOffset().
497 *
498 * @param date moment in time for which to return offsets, in
499 * units of milliseconds from January 1, 1970 0:00 GMT, either GMT
500 * time or local wall time, depending on `local'.
501 * @param local if true, `date' is local wall time; otherwise it
502 * is in GMT time.
503 * @param rawOffset output parameter to receive the raw offset, that
504 * is, the offset not including DST adjustments
505 * @param dstOffset output parameter to receive the DST offset,
506 * that is, the offset to be added to `rawOffset' to obtain the
507 * total offset between local and GMT time. If DST is not in
508 * effect, this value is zero; otherwise it is a positive value,
509 * typically one hour.
510 * @param ec input-output error code
511 *
512 * @stable ICU 2.8
513 */
514 virtual void getOffset(UDate date, UBool local, int32_t& rawOffset,
515 int32_t& dstOffset, UErrorCode& ec) const;
516
517 /**
518 * Sets the TimeZone's raw GMT offset (i.e., the number of milliseconds to add
519 * to GMT to get local time, before taking daylight savings time into account).
520 *
521 * @param offsetMillis The new raw GMT offset for this time zone.
522 * @stable ICU 2.0
523 */
524 virtual void setRawOffset(int32_t offsetMillis) = 0;
525
526 /**
527 * Returns the TimeZone's raw GMT offset (i.e., the number of milliseconds to add
528 * to GMT to get local time, before taking daylight savings time into account).
529 *
530 * @return The TimeZone's raw GMT offset.
531 * @stable ICU 2.0
532 */
533 virtual int32_t getRawOffset(void) const = 0;
534
535 /**
536 * Fills in "ID" with the TimeZone's ID.
537 *
538 * @param ID Receives this TimeZone's ID.
539 * @return A reference to 'ID'
540 * @stable ICU 2.0
541 */
542 UnicodeString& getID(UnicodeString& ID) const;
543
544 /**
545 * Sets the TimeZone's ID to the specified value. This doesn't affect any other
546 * fields (for example, if you say<
547 * blockquote><pre>
548 * . TimeZone* foo = TimeZone::createTimeZone("America/New_York");
549 * . foo.setID("America/Los_Angeles");
550 * </pre>\htmlonly</blockquote>\endhtmlonly
551 * the time zone's GMT offset and daylight-savings rules don't change to those for
552 * Los Angeles. They're still those for New York. Only the ID has changed.)
553 *
554 * @param ID The new time zone ID.
555 * @stable ICU 2.0
556 */
557 void setID(const UnicodeString& ID);
558
559 /**
560 * Enum for use with getDisplayName
561 * @stable ICU 2.4
562 */
563 enum EDisplayType {
564 /**
565 * Selector for short display name
566 * @stable ICU 2.4
567 */
568 SHORT = 1,
569 /**
570 * Selector for long display name
571 * @stable ICU 2.4
572 */
573 LONG,
574 /**
575 * Selector for short generic display name
576 * @stable ICU 4.4
577 */
578 SHORT_GENERIC,
579 /**
580 * Selector for long generic display name
581 * @stable ICU 4.4
582 */
583 LONG_GENERIC,
584 /**
585 * Selector for short display name derived
586 * from time zone offset
587 * @stable ICU 4.4
588 */
589 SHORT_GMT,
590 /**
591 * Selector for long display name derived
592 * from time zone offset
593 * @stable ICU 4.4
594 */
595 LONG_GMT,
596 /**
597 * Selector for short display name derived
598 * from the time zone's fallback name
599 * @stable ICU 4.4
600 */
601 SHORT_COMMONLY_USED,
602 /**
603 * Selector for long display name derived
604 * from the time zone's fallback name
605 * @stable ICU 4.4
606 */
607 GENERIC_LOCATION
608 };
609
610 /**
611 * Returns a name of this time zone suitable for presentation to the user
612 * in the default locale.
613 * This method returns the long name, not including daylight savings.
614 * If the display name is not available for the locale,
615 * then this method returns a string in the format
616 * <code>GMT[+-]hh:mm</code>.
617 * @param result the human-readable name of this time zone in the default locale.
618 * @return A reference to 'result'.
619 * @stable ICU 2.0
620 */
621 UnicodeString& getDisplayName(UnicodeString& result) const;
622
623 /**
624 * Returns a name of this time zone suitable for presentation to the user
625 * in the specified locale.
626 * This method returns the long name, not including daylight savings.
627 * If the display name is not available for the locale,
628 * then this method returns a string in the format
629 * <code>GMT[+-]hh:mm</code>.
630 * @param locale the locale in which to supply the display name.
631 * @param result the human-readable name of this time zone in the given locale
632 * or in the default locale if the given locale is not recognized.
633 * @return A reference to 'result'.
634 * @stable ICU 2.0
635 */
636 UnicodeString& getDisplayName(const Locale& locale, UnicodeString& result) const;
637
638 /**
639 * Returns a name of this time zone suitable for presentation to the user
640 * in the default locale.
641 * If the display name is not available for the locale,
642 * then this method returns a string in the format
643 * <code>GMT[+-]hh:mm</code>.
644 * @param daylight if true, return the daylight savings name.
645 * @param style
646 * @param result the human-readable name of this time zone in the default locale.
647 * @return A reference to 'result'.
648 * @stable ICU 2.0
649 */
650 UnicodeString& getDisplayName(UBool daylight, EDisplayType style, UnicodeString& result) const;
651
652 /**
653 * Returns a name of this time zone suitable for presentation to the user
654 * in the specified locale.
655 * If the display name is not available for the locale,
656 * then this method returns a string in the format
657 * <code>GMT[+-]hh:mm</code>.
658 * @param daylight if true, return the daylight savings name.
659 * @param style
660 * @param locale the locale in which to supply the display name.
661 * @param result the human-readable name of this time zone in the given locale
662 * or in the default locale if the given locale is not recognized.
663 * @return A refence to 'result'.
664 * @stable ICU 2.0
665 */
666 UnicodeString& getDisplayName(UBool daylight, EDisplayType style, const Locale& locale, UnicodeString& result) const;
667
668 /**
669 * Queries if this time zone uses daylight savings time.
670 * @return true if this time zone uses daylight savings time,
671 * false, otherwise.
672 * <p><strong>Note:</strong>The default implementation of
673 * ICU TimeZone uses the tz database, which supports historic
674 * rule changes, for system time zones. With the implementation,
675 * there are time zones that used daylight savings time in the
676 * past, but no longer used currently. For example, Asia/Tokyo has
677 * never used daylight savings time since 1951. Most clients would
678 * expect that this method to return <code>FALSE</code> for such case.
679 * The default implementation of this method returns <code>TRUE</code>
680 * when the time zone uses daylight savings time in the current
681 * (Gregorian) calendar year.
682 * <p>In Java 7, <code>observesDaylightTime()</code> was added in
683 * addition to <code>useDaylightTime()</code>. In Java, <code>useDaylightTime()</code>
684 * only checks if daylight saving time is observed by the last known
685 * rule. This specification might not be what most users would expect
686 * if daylight saving time is currently observed, but not scheduled
687 * in future. In this case, Java's <code>userDaylightTime()</code> returns
688 * <code>false</code>. To resolve the issue, Java 7 added <code>observesDaylightTime()</code>,
689 * which takes the current rule into account. The method <code>observesDaylightTime()</code>
690 * was added in ICU4J for supporting API signature compatibility with JDK.
691 * In general, ICU4C also provides JDK compatible methods, but the current
692 * implementation <code>userDaylightTime()</code> serves the purpose
693 * (takes the current rule into account), <code>observesDaylightTime()</code>
694 * is not added in ICU4C. In addition to <code>useDaylightTime()</code>, ICU4C
695 * <code>BasicTimeZone</code> class (Note that <code>TimeZone::createTimeZone(const UnicodeString &ID)</code>
696 * always returns a <code>BasicTimeZone</code>) provides a series of methods allowing
697 * historic and future time zone rule iteration, so you can check if daylight saving
698 * time is observed or not within a given period.
699 *
700 * @stable ICU 2.0
701 */
702 virtual UBool useDaylightTime(void) const = 0;
703
704 /**
705 * Queries if the given date is in daylight savings time in
706 * this time zone.
707 * This method is wasteful since it creates a new GregorianCalendar and
708 * deletes it each time it is called. This is a deprecated method
709 * and provided only for Java compatibility.
710 *
711 * @param date the given UDate.
712 * @param status Output param filled in with success/error code.
713 * @return true if the given date is in daylight savings time,
714 * false, otherwise.
715 * @deprecated ICU 2.4. Use Calendar::inDaylightTime() instead.
716 */
717 virtual UBool inDaylightTime(UDate date, UErrorCode& status) const = 0;
718
719 /**
720 * Returns true if this zone has the same rule and offset as another zone.
721 * That is, if this zone differs only in ID, if at all.
722 * @param other the <code>TimeZone</code> object to be compared with
723 * @return true if the given zone is the same as this one,
724 * with the possible exception of the ID
725 * @stable ICU 2.0
726 */
727 virtual UBool hasSameRules(const TimeZone& other) const;
728
729 /**
730 * Clones TimeZone objects polymorphically. Clients are responsible for deleting
731 * the TimeZone object cloned.
732 *
733 * @return A new copy of this TimeZone object.
734 * @stable ICU 2.0
735 */
736 virtual TimeZone* clone(void) const = 0;
737
738 /**
739 * Return the class ID for this class. This is useful only for
740 * comparing to a return value from getDynamicClassID().
741 * @return The class ID for all objects of this class.
742 * @stable ICU 2.0
743 */
744 static UClassID U_EXPORT2 getStaticClassID(void);
745
746 /**
747 * Returns a unique class ID POLYMORPHICALLY. This method is to
748 * implement a simple version of RTTI, since not all C++ compilers support genuine
749 * RTTI. Polymorphic operator==() and clone() methods call this method.
750 * <P>
751 * Concrete subclasses of TimeZone must use the UOBJECT_DEFINE_RTTI_IMPLEMENTATION
752 * macro from uobject.h in their implementation to provide correct RTTI information.
753 * @return The class ID for this object. All objects of a given class have the
754 * same class ID. Objects of other classes have different class IDs.
755 * @stable ICU 2.0
756 */
757 virtual UClassID getDynamicClassID(void) const = 0;
758
759 /**
760 * Returns the amount of time to be added to local standard time
761 * to get local wall clock time.
762 * <p>
763 * The default implementation always returns 3600000 milliseconds
764 * (i.e., one hour) if this time zone observes Daylight Saving
765 * Time. Otherwise, 0 (zero) is returned.
766 * <p>
767 * If an underlying TimeZone implementation subclass supports
768 * historical Daylight Saving Time changes, this method returns
769 * the known latest daylight saving value.
770 *
771 * @return the amount of saving time in milliseconds
772 * @stable ICU 3.6
773 */
774 virtual int32_t getDSTSavings() const;
775
776 /**
777 * Gets the region code associated with the given
778 * system time zone ID. The region code is either ISO 3166
779 * 2-letter country code or UN M.49 3-digit area code.
780 * When the time zone is not associated with a specific location,
781 * for example - "Etc/UTC", "EST5EDT", then this method returns
782 * "001" (UN M.49 area code for World).
783 *
784 * @param id The system time zone ID.
785 * @param region Output buffer for receiving the region code.
786 * @param capacity The size of the output buffer.
787 * @param status Receives the status. When the given time zone ID
788 * is not a known system time zone ID,
789 * U_ILLEGAL_ARGUMENT_ERROR is set.
790 * @return The length of the output region code.
791 * @stable ICU 4.8
792 */
793 static int32_t U_EXPORT2 getRegion(const UnicodeString& id,
794 char *region, int32_t capacity, UErrorCode& status);
795
796 protected:
797
798 /**
799 * Default constructor. ID is initialized to the empty string.
800 * @stable ICU 2.0
801 */
802 TimeZone();
803
804 /**
805 * Construct a TimeZone with a given ID.
806 * @param id a system time zone ID
807 * @stable ICU 2.0
808 */
809 TimeZone(const UnicodeString &id);
810
811 /**
812 * Copy constructor.
813 * @param source the object to be copied.
814 * @stable ICU 2.0
815 */
816 TimeZone(const TimeZone& source);
817
818 /**
819 * Default assignment operator.
820 * @param right the object to be copied.
821 * @stable ICU 2.0
822 */
823 TimeZone& operator=(const TimeZone& right);
824
825 #ifndef U_HIDE_INTERNAL_API
826 /**
827 * Utility function. For internally loading rule data.
828 * @param top Top resource bundle for tz data
829 * @param ruleid ID of rule to load
830 * @param oldbundle Old bundle to reuse or NULL
831 * @param status Status parameter
832 * @return either a new bundle or *oldbundle
833 * @internal
834 */
835 static UResourceBundle* loadRule(const UResourceBundle* top, const UnicodeString& ruleid, UResourceBundle* oldbundle, UErrorCode&status);
836 #endif /* U_HIDE_INTERNAL_API */
837
838 private:
839 friend class ZoneMeta;
840
841
842 static TimeZone* createCustomTimeZone(const UnicodeString&); // Creates a time zone based on the string.
843
844 /**
845 * Finds the given ID in the Olson tzdata. If the given ID is found in the tzdata,
846 * returns the pointer to the ID resource. This method is exposed through ZoneMeta class
847 * for ICU internal implementation and useful for building hashtable using a time zone
848 * ID as a key.
849 * @param id zone id string
850 * @return the pointer of the ID resource, or NULL.
851 */
852 static const UChar* findID(const UnicodeString& id);
853
854 /**
855 * Resolve a link in Olson tzdata. When the given id is known and it's not a link,
856 * the id itself is returned. When the given id is known and it is a link, then
857 * dereferenced zone id is returned. When the given id is unknown, then it returns
858 * NULL.
859 * @param id zone id string
860 * @return the dereferenced zone or NULL
861 */
862 static const UChar* dereferOlsonLink(const UnicodeString& id);
863
864 /**
865 * Returns the region code associated with the given zone,
866 * or NULL if the zone is not known.
867 * @param id zone id string
868 * @return the region associated with the given zone
869 */
870 static const UChar* getRegion(const UnicodeString& id);
871
872 public:
873 #ifndef U_HIDE_INTERNAL_API
874 /**
875 * Returns the region code associated with the given zone,
876 * or NULL if the zone is not known.
877 * @param id zone id string
878 * @param status Status parameter
879 * @return the region associated with the given zone
880 * @internal
881 */
882 static const UChar* getRegion(const UnicodeString& id, UErrorCode& status);
883 #endif /* U_HIDE_INTERNAL_API */
884
885 private:
886 /**
887 * Parses the given custom time zone identifier
888 * @param id id A string of the form GMT[+-]hh:mm, GMT[+-]hhmm, or
889 * GMT[+-]hh.
890 * @param sign Receves parsed sign, 1 for positive, -1 for negative.
891 * @param hour Receives parsed hour field
892 * @param minute Receives parsed minute field
893 * @param second Receives parsed second field
894 * @return Returns TRUE when the given custom id is valid.
895 */
896 static UBool parseCustomID(const UnicodeString& id, int32_t& sign, int32_t& hour,
897 int32_t& minute, int32_t& second);
898
899 /**
900 * Parse a custom time zone identifier and return the normalized
901 * custom time zone identifier for the given custom id string.
902 * @param id a string of the form GMT[+-]hh:mm, GMT[+-]hhmm, or
903 * GMT[+-]hh.
904 * @param normalized Receives the normalized custom ID
905 * @param status Receives the status. When the input ID string is invalid,
906 * U_ILLEGAL_ARGUMENT_ERROR is set.
907 * @return The normalized custom id string.
908 */
909 static UnicodeString& getCustomID(const UnicodeString& id, UnicodeString& normalized,
910 UErrorCode& status);
911
912 /**
913 * Returns the normalized custome time zone ID for the given offset fields.
914 * @param hour offset hours
915 * @param min offset minutes
916 * @param sec offset seconds
917 * @param negative sign of the offset, TRUE for negative offset.
918 * @param id Receves the format result (normalized custom ID)
919 * @return The reference to id
920 */
921 static UnicodeString& formatCustomID(int32_t hour, int32_t min, int32_t sec,
922 UBool negative, UnicodeString& id);
923
924 UnicodeString fID; // this time zone's ID
925
926 friend class TZEnumeration;
927 };
928
929
930 // -------------------------------------
931
932 inline UnicodeString&
getID(UnicodeString & ID)933 TimeZone::getID(UnicodeString& ID) const
934 {
935 ID = fID;
936 return ID;
937 }
938
939 // -------------------------------------
940
941 inline void
setID(const UnicodeString & ID)942 TimeZone::setID(const UnicodeString& ID)
943 {
944 fID = ID;
945 }
946 U_NAMESPACE_END
947
948 #endif /* #if !UCONFIG_NO_FORMATTING */
949
950 #endif //_TIMEZONE
951 //eof
952