1 // 2016 and later: Unicode, Inc. and others. 2 // License & terms of use: http://www.unicode.org/copyright.html 3 /************************************************************************* 4 * Copyright (c) 1997-2016, International Business Machines Corporation 5 * and others. All Rights Reserved. 6 ************************************************************************** 7 * 8 * File TIMEZONE.H 9 * 10 * Modification History: 11 * 12 * Date Name Description 13 * 04/21/97 aliu Overhauled header. 14 * 07/09/97 helena Changed createInstance to createDefault. 15 * 08/06/97 aliu Removed dependency on internal header for Hashtable. 16 * 08/10/98 stephen Changed getDisplayName() API conventions to match 17 * 08/19/98 stephen Changed createTimeZone() to never return 0 18 * 09/02/98 stephen Sync to JDK 1.2 8/31 19 * - Added getOffset(... monthlen ...) 20 * - Added hasSameRules() 21 * 09/15/98 stephen Added getStaticClassID 22 * 12/03/99 aliu Moved data out of static table into icudata.dll. 23 * Hashtable replaced by new static data structures. 24 * 12/14/99 aliu Made GMT public. 25 * 08/15/01 grhoten Made GMT private and added the getGMT() function 26 ************************************************************************** 27 */ 28 29 #ifndef TIMEZONE_H 30 #define TIMEZONE_H 31 32 #include "unicode/utypes.h" 33 34 /** 35 * \file 36 * \brief C++ API: TimeZone object 37 */ 38 39 #if !UCONFIG_NO_FORMATTING 40 41 #include "unicode/uobject.h" 42 #include "unicode/unistr.h" 43 #include "unicode/ures.h" 44 #include "unicode/ucal.h" 45 46 U_NAMESPACE_BEGIN 47 48 class StringEnumeration; 49 50 /** 51 * 52 * <code>TimeZone</code> represents a time zone offset, and also figures out daylight 53 * savings. 54 * 55 * <p> 56 * Typically, you get a <code>TimeZone</code> using <code>createDefault</code> 57 * which creates a <code>TimeZone</code> based on the time zone where the program 58 * is running. For example, for a program running in Japan, <code>createDefault</code> 59 * creates a <code>TimeZone</code> object based on Japanese Standard Time. 60 * 61 * <p> 62 * You can also get a <code>TimeZone</code> using <code>createTimeZone</code> along 63 * with a time zone ID. For instance, the time zone ID for the US Pacific 64 * Time zone is "America/Los_Angeles". So, you can get a Pacific Time <code>TimeZone</code> object 65 * with: 66 * \htmlonly<blockquote>\endhtmlonly 67 * <pre> 68 * TimeZone *tz = TimeZone::createTimeZone("America/Los_Angeles"); 69 * </pre> 70 * \htmlonly</blockquote>\endhtmlonly 71 * You can use the <code>createEnumeration</code> method to iterate through 72 * all the supported time zone IDs, or the <code>getCanonicalID</code> method to check 73 * if a time zone ID is supported or not. You can then choose a 74 * supported ID to get a <code>TimeZone</code>. 75 * If the time zone you want is not represented by one of the 76 * supported IDs, then you can create a custom time zone ID with 77 * the following syntax: 78 * 79 * \htmlonly<blockquote>\endhtmlonly 80 * <pre> 81 * GMT[+|-]hh[[:]mm] 82 * </pre> 83 * \htmlonly</blockquote>\endhtmlonly 84 * 85 * For example, you might specify GMT+14:00 as a custom 86 * time zone ID. The <code>TimeZone</code> that is returned 87 * when you specify a custom time zone ID uses the specified 88 * offset from GMT(=UTC) and does not observe daylight saving 89 * time. For example, you might specify GMT+14:00 as a custom 90 * time zone ID to create a TimeZone representing 14 hours ahead 91 * of GMT (with no daylight saving time). In addition, 92 * <code>getCanonicalID</code> can also be used to 93 * normalize a custom time zone ID. 94 * 95 * TimeZone is an abstract class representing a time zone. A TimeZone is needed for 96 * Calendar to produce local time for a particular time zone. A TimeZone comprises 97 * three basic pieces of information: 98 * <ul> 99 * <li>A time zone offset; that, is the number of milliseconds to add or subtract 100 * from a time expressed in terms of GMT to convert it to the same time in that 101 * time zone (without taking daylight savings time into account).</li> 102 * <li>Logic necessary to take daylight savings time into account if daylight savings 103 * time is observed in that time zone (e.g., the days and hours on which daylight 104 * savings time begins and ends).</li> 105 * <li>An ID. This is a text string that uniquely identifies the time zone.</li> 106 * </ul> 107 * 108 * (Only the ID is actually implemented in TimeZone; subclasses of TimeZone may handle 109 * daylight savings time and GMT offset in different ways. Currently we have the following 110 * TimeZone subclasses: RuleBasedTimeZone, SimpleTimeZone, and VTimeZone.) 111 * <P> 112 * The TimeZone class contains a static list containing a TimeZone object for every 113 * combination of GMT offset and daylight-savings time rules currently in use in the 114 * world, each with a unique ID. Each ID consists of a region (usually a continent or 115 * ocean) and a city in that region, separated by a slash, (for example, US Pacific 116 * Time is "America/Los_Angeles.") Because older versions of this class used 117 * three- or four-letter abbreviations instead, there is also a table that maps the older 118 * abbreviations to the newer ones (for example, "PST" maps to "America/Los_Angeles"). 119 * Anywhere the API requires an ID, you can use either form. 120 * <P> 121 * To create a new TimeZone, you call the factory function TimeZone::createTimeZone() 122 * and pass it a time zone ID. You can use the createEnumeration() function to 123 * obtain a list of all the time zone IDs recognized by createTimeZone(). 124 * <P> 125 * You can also use TimeZone::createDefault() to create a TimeZone. This function uses 126 * platform-specific APIs to produce a TimeZone for the time zone corresponding to 127 * the client's computer's physical location. For example, if you're in Japan (assuming 128 * your machine is set up correctly), TimeZone::createDefault() will return a TimeZone 129 * for Japanese Standard Time ("Asia/Tokyo"). 130 */ 131 class U_I18N_API TimeZone : public UObject { 132 public: 133 /** 134 * @stable ICU 2.0 135 */ 136 virtual ~TimeZone(); 137 138 /** 139 * Returns the "unknown" time zone. 140 * It behaves like the GMT/UTC time zone but has the 141 * <code>UCAL_UNKNOWN_ZONE_ID</code> = "Etc/Unknown". 142 * createTimeZone() returns a mutable clone of this time zone if the input ID is not recognized. 143 * 144 * @return the "unknown" time zone. 145 * @see UCAL_UNKNOWN_ZONE_ID 146 * @see createTimeZone 147 * @see getGMT 148 * @stable ICU 49 149 */ 150 static const TimeZone& U_EXPORT2 getUnknown(); 151 152 /** 153 * The GMT (=UTC) time zone has a raw offset of zero and does not use daylight 154 * savings time. This is a commonly used time zone. 155 * 156 * <p>Note: For backward compatibility reason, the ID used by the time 157 * zone returned by this method is "GMT", although the ICU's canonical 158 * ID for the GMT time zone is "Etc/GMT". 159 * 160 * @return the GMT/UTC time zone. 161 * @see getUnknown 162 * @stable ICU 2.0 163 */ 164 static const TimeZone* U_EXPORT2 getGMT(void); 165 166 /** 167 * Creates a <code>TimeZone</code> for the given ID. 168 * @param ID the ID for a <code>TimeZone</code>, such as "America/Los_Angeles", 169 * or a custom ID such as "GMT-8:00". 170 * @return the specified <code>TimeZone</code>, or a mutable clone of getUnknown() 171 * if the given ID cannot be understood or if the given ID is "Etc/Unknown". 172 * The return result is guaranteed to be non-NULL. 173 * If you require that the specific zone asked for be returned, 174 * compare the result with getUnknown() or check the ID of the return result. 175 * @stable ICU 2.0 176 */ 177 static TimeZone* U_EXPORT2 createTimeZone(const UnicodeString& ID); 178 179 /** 180 * Returns an enumeration over system time zone IDs with the given 181 * filter conditions. 182 * @param zoneType The system time zone type. 183 * @param region The ISO 3166 two-letter country code or UN M.49 184 * three-digit area code. When NULL, no filtering 185 * done by region. 186 * @param rawOffset An offset from GMT in milliseconds, ignoring 187 * the effect of daylight savings time, if any. 188 * When NULL, no filtering done by zone offset. 189 * @param ec Output param to filled in with a success or 190 * an error. 191 * @return an enumeration object, owned by the caller. 192 * @stable ICU 4.8 193 */ 194 static StringEnumeration* U_EXPORT2 createTimeZoneIDEnumeration( 195 USystemTimeZoneType zoneType, 196 const char* region, 197 const int32_t* rawOffset, 198 UErrorCode& ec); 199 200 /** 201 * Returns an enumeration over all recognized time zone IDs. (i.e., 202 * all strings that createTimeZone() accepts) 203 * 204 * @return an enumeration object, owned by the caller. 205 * @stable ICU 2.4 206 */ 207 static StringEnumeration* U_EXPORT2 createEnumeration(); 208 209 /** 210 * Returns an enumeration over time zone IDs with a given raw 211 * offset from GMT. There may be several times zones with the 212 * same GMT offset that differ in the way they handle daylight 213 * savings time. For example, the state of Arizona doesn't 214 * observe daylight savings time. If you ask for the time zone 215 * IDs corresponding to GMT-7:00, you'll get back an enumeration 216 * over two time zone IDs: "America/Denver," which corresponds to 217 * Mountain Standard Time in the winter and Mountain Daylight Time 218 * in the summer, and "America/Phoenix", which corresponds to 219 * Mountain Standard Time year-round, even in the summer. 220 * 221 * @param rawOffset an offset from GMT in milliseconds, ignoring 222 * the effect of daylight savings time, if any 223 * @return an enumeration object, owned by the caller 224 * @stable ICU 2.4 225 */ 226 static StringEnumeration* U_EXPORT2 createEnumeration(int32_t rawOffset); 227 228 /** 229 * Returns an enumeration over time zone IDs associated with the 230 * given country. Some zones are affiliated with no country 231 * (e.g., "UTC"); these may also be retrieved, as a group. 232 * 233 * @param country The ISO 3166 two-letter country code, or NULL to 234 * retrieve zones not affiliated with any country. 235 * @return an enumeration object, owned by the caller 236 * @stable ICU 2.4 237 */ 238 static StringEnumeration* U_EXPORT2 createEnumeration(const char* country); 239 240 /** 241 * Returns the number of IDs in the equivalency group that 242 * includes the given ID. An equivalency group contains zones 243 * that have the same GMT offset and rules. 244 * 245 * <p>The returned count includes the given ID; it is always >= 1. 246 * The given ID must be a system time zone. If it is not, returns 247 * zero. 248 * @param id a system time zone ID 249 * @return the number of zones in the equivalency group containing 250 * 'id', or zero if 'id' is not a valid system ID 251 * @see #getEquivalentID 252 * @stable ICU 2.0 253 */ 254 static int32_t U_EXPORT2 countEquivalentIDs(const UnicodeString& id); 255 256 /** 257 * Returns an ID in the equivalency group that 258 * includes the given ID. An equivalency group contains zones 259 * that have the same GMT offset and rules. 260 * 261 * <p>The given index must be in the range 0..n-1, where n is the 262 * value returned by <code>countEquivalentIDs(id)</code>. For 263 * some value of 'index', the returned value will be equal to the 264 * given id. If the given id is not a valid system time zone, or 265 * if 'index' is out of range, then returns an empty string. 266 * @param id a system time zone ID 267 * @param index a value from 0 to n-1, where n is the value 268 * returned by <code>countEquivalentIDs(id)</code> 269 * @return the ID of the index-th zone in the equivalency group 270 * containing 'id', or an empty string if 'id' is not a valid 271 * system ID or 'index' is out of range 272 * @see #countEquivalentIDs 273 * @stable ICU 2.0 274 */ 275 static const UnicodeString U_EXPORT2 getEquivalentID(const UnicodeString& id, 276 int32_t index); 277 278 /** 279 * Creates an instance of TimeZone detected from the current host 280 * system configuration. Note that ICU4C does not change the default 281 * time zone unless TimeZone::adoptDefault(TimeZone*) or 282 * TimeZone::setDefault(const TimeZone&) is explicitly called by a 283 * user. This method does not update the current ICU's default, 284 * and may return a different TimeZone from the one returned by 285 * TimeZone::createDefault(). 286 * 287 * <p>This function is not thread safe.</p> 288 * 289 * @return A new instance of TimeZone detected from the current host system 290 * configuration. 291 * @stable ICU 55 292 */ 293 static TimeZone* U_EXPORT2 detectHostTimeZone(); 294 295 /** 296 * Creates a new copy of the default TimeZone for this host. Unless the default time 297 * zone has already been set using adoptDefault() or setDefault(), the default is 298 * determined by querying the system using methods in TPlatformUtilities. If the 299 * system routines fail, or if they specify a TimeZone or TimeZone offset which is not 300 * recognized, the TimeZone indicated by the ID kLastResortID is instantiated 301 * and made the default. 302 * 303 * @return A default TimeZone. Clients are responsible for deleting the time zone 304 * object returned. 305 * @stable ICU 2.0 306 */ 307 static TimeZone* U_EXPORT2 createDefault(void); 308 309 /** 310 * Sets the default time zone (i.e., what's returned by createDefault()) to be the 311 * specified time zone. If NULL is specified for the time zone, the default time 312 * zone is set to the default host time zone. This call adopts the TimeZone object 313 * passed in; the client is no longer responsible for deleting it. 314 * 315 * <p>This function is not thread safe. It is an error for multiple threads 316 * to concurrently attempt to set the default time zone, or for any thread 317 * to attempt to reference the default zone while another thread is setting it. 318 * 319 * @param zone A pointer to the new TimeZone object to use as the default. 320 * @stable ICU 2.0 321 */ 322 static void U_EXPORT2 adoptDefault(TimeZone* zone); 323 324 #ifndef U_HIDE_SYSTEM_API 325 /** 326 * Same as adoptDefault(), except that the TimeZone object passed in is NOT adopted; 327 * the caller remains responsible for deleting it. 328 * 329 * <p>See the thread safety note under adoptDefault(). 330 * 331 * @param zone The given timezone. 332 * @system 333 * @stable ICU 2.0 334 */ 335 static void U_EXPORT2 setDefault(const TimeZone& zone); 336 #endif /* U_HIDE_SYSTEM_API */ 337 338 /** 339 * Returns the timezone data version currently used by ICU. 340 * @param status Output param to filled in with a success or an error. 341 * @return the version string, such as "2007f" 342 * @stable ICU 3.8 343 */ 344 static const char* U_EXPORT2 getTZDataVersion(UErrorCode& status); 345 346 /** 347 * Returns the canonical system timezone ID or the normalized 348 * custom time zone ID for the given time zone ID. 349 * @param id The input time zone ID to be canonicalized. 350 * @param canonicalID Receives the canonical system time zone ID 351 * or the custom time zone ID in normalized format. 352 * @param status Receives the status. When the given time zone ID 353 * is neither a known system time zone ID nor a 354 * valid custom time zone ID, U_ILLEGAL_ARGUMENT_ERROR 355 * is set. 356 * @return A reference to the result. 357 * @stable ICU 4.0 358 */ 359 static UnicodeString& U_EXPORT2 getCanonicalID(const UnicodeString& id, 360 UnicodeString& canonicalID, UErrorCode& status); 361 362 /** 363 * Returns the canonical system time zone ID or the normalized 364 * custom time zone ID for the given time zone ID. 365 * @param id The input time zone ID to be canonicalized. 366 * @param canonicalID Receives the canonical system time zone ID 367 * or the custom time zone ID in normalized format. 368 * @param isSystemID Receives if the given ID is a known system 369 * time zone ID. 370 * @param status Receives the status. When the given time zone ID 371 * is neither a known system time zone ID nor a 372 * valid custom time zone ID, U_ILLEGAL_ARGUMENT_ERROR 373 * is set. 374 * @return A reference to the result. 375 * @stable ICU 4.0 376 */ 377 static UnicodeString& U_EXPORT2 getCanonicalID(const UnicodeString& id, 378 UnicodeString& canonicalID, UBool& isSystemID, UErrorCode& status); 379 380 /** 381 * Converts a system time zone ID to an equivalent Windows time zone ID. For example, 382 * Windows time zone ID "Pacific Standard Time" is returned for input "America/Los_Angeles". 383 * 384 * <p>There are system time zones that cannot be mapped to Windows zones. When the input 385 * system time zone ID is unknown or unmappable to a Windows time zone, then the result will be 386 * empty, but the operation itself remains successful (no error status set on return). 387 * 388 * <p>This implementation utilizes <a href="http://unicode.org/cldr/charts/supplemental/zone_tzid.html"> 389 * Zone-Tzid mapping data</a>. The mapping data is updated time to time. To get the latest changes, 390 * please read the ICU user guide section <a href="http://userguide.icu-project.org/datetime/timezone#TOC-Updating-the-Time-Zone-Data"> 391 * Updating the Time Zone Data</a>. 392 * 393 * @param id A system time zone ID. 394 * @param winid Receives a Windows time zone ID. When the input system time zone ID is unknown 395 * or unmappable to a Windows time zone ID, then an empty string is set on return. 396 * @param status Receives the status. 397 * @return A reference to the result (<code>winid</code>). 398 * @see getIDForWindowsID 399 * 400 * @stable ICU 52 401 */ 402 static UnicodeString& U_EXPORT2 getWindowsID(const UnicodeString& id, 403 UnicodeString& winid, UErrorCode& status); 404 405 /** 406 * Converts a Windows time zone ID to an equivalent system time zone ID 407 * for a region. For example, system time zone ID "America/Los_Angeles" is returned 408 * for input Windows ID "Pacific Standard Time" and region "US" (or <code>null</code>), 409 * "America/Vancouver" is returned for the same Windows ID "Pacific Standard Time" and 410 * region "CA". 411 * 412 * <p>Not all Windows time zones can be mapped to system time zones. When the input 413 * Windows time zone ID is unknown or unmappable to a system time zone, then the result 414 * will be empty, but the operation itself remains successful (no error status set on return). 415 * 416 * <p>This implementation utilizes <a href="http://unicode.org/cldr/charts/supplemental/zone_tzid.html"> 417 * Zone-Tzid mapping data</a>. The mapping data is updated time to time. To get the latest changes, 418 * please read the ICU user guide section <a href="http://userguide.icu-project.org/datetime/timezone#TOC-Updating-the-Time-Zone-Data"> 419 * Updating the Time Zone Data</a>. 420 * 421 * @param winid A Windows time zone ID. 422 * @param region A null-terminated region code, or <code>NULL</code> if no regional preference. 423 * @param id Receives a system time zone ID. When the input Windows time zone ID is unknown 424 * or unmappable to a system time zone ID, then an empty string is set on return. 425 * @param status Receives the status. 426 * @return A reference to the result (<code>id</code>). 427 * @see getWindowsID 428 * 429 * @stable ICU 52 430 */ 431 static UnicodeString& U_EXPORT2 getIDForWindowsID(const UnicodeString& winid, const char* region, 432 UnicodeString& id, UErrorCode& status); 433 434 /** 435 * Returns true if the two TimeZones are equal. (The TimeZone version only compares 436 * IDs, but subclasses are expected to also compare the fields they add.) 437 * 438 * @param that The TimeZone object to be compared with. 439 * @return True if the given TimeZone is equal to this TimeZone; false 440 * otherwise. 441 * @stable ICU 2.0 442 */ 443 virtual UBool operator==(const TimeZone& that) const; 444 445 /** 446 * Returns true if the two TimeZones are NOT equal; that is, if operator==() returns 447 * false. 448 * 449 * @param that The TimeZone object to be compared with. 450 * @return True if the given TimeZone is not equal to this TimeZone; false 451 * otherwise. 452 * @stable ICU 2.0 453 */ 454 UBool operator!=(const TimeZone& that) const {return !operator==(that);} 455 456 /** 457 * Returns the TimeZone's adjusted GMT offset (i.e., the number of milliseconds to add 458 * to GMT to get local time in this time zone, taking daylight savings time into 459 * account) as of a particular reference date. The reference date is used to determine 460 * whether daylight savings time is in effect and needs to be figured into the offset 461 * that is returned (in other words, what is the adjusted GMT offset in this time zone 462 * at this particular date and time?). For the time zones produced by createTimeZone(), 463 * the reference data is specified according to the Gregorian calendar, and the date 464 * and time fields are local standard time. 465 * 466 * <p>Note: Don't call this method. Instead, call the getOffset(UDate...) overload, 467 * which returns both the raw and the DST offset for a given time. This method 468 * is retained only for backward compatibility. 469 * 470 * @param era The reference date's era 471 * @param year The reference date's year 472 * @param month The reference date's month (0-based; 0 is January) 473 * @param day The reference date's day-in-month (1-based) 474 * @param dayOfWeek The reference date's day-of-week (1-based; 1 is Sunday) 475 * @param millis The reference date's milliseconds in day, local standard time 476 * @param status Output param to filled in with a success or an error. 477 * @return The offset in milliseconds to add to GMT to get local time. 478 * @stable ICU 2.0 479 */ 480 virtual int32_t getOffset(uint8_t era, int32_t year, int32_t month, int32_t day, 481 uint8_t dayOfWeek, int32_t millis, UErrorCode& status) const = 0; 482 483 /** 484 * Gets the time zone offset, for current date, modified in case of 485 * daylight savings. This is the offset to add *to* UTC to get local time. 486 * 487 * <p>Note: Don't call this method. Instead, call the getOffset(UDate...) overload, 488 * which returns both the raw and the DST offset for a given time. This method 489 * is retained only for backward compatibility. 490 * 491 * @param era the era of the given date. 492 * @param year the year in the given date. 493 * @param month the month in the given date. 494 * Month is 0-based. e.g., 0 for January. 495 * @param day the day-in-month of the given date. 496 * @param dayOfWeek the day-of-week of the given date. 497 * @param milliseconds the millis in day in <em>standard</em> local time. 498 * @param monthLength the length of the given month in days. 499 * @param status Output param to filled in with a success or an error. 500 * @return the offset to add *to* GMT to get local time. 501 * @stable ICU 2.0 502 */ 503 virtual int32_t getOffset(uint8_t era, int32_t year, int32_t month, int32_t day, 504 uint8_t dayOfWeek, int32_t milliseconds, 505 int32_t monthLength, UErrorCode& status) const = 0; 506 507 /** 508 * Returns the time zone raw and GMT offset for the given moment 509 * in time. Upon return, local-millis = GMT-millis + rawOffset + 510 * dstOffset. All computations are performed in the proleptic 511 * Gregorian calendar. The default implementation in the TimeZone 512 * class delegates to the 8-argument getOffset(). 513 * 514 * @param date moment in time for which to return offsets, in 515 * units of milliseconds from January 1, 1970 0:00 GMT, either GMT 516 * time or local wall time, depending on `local'. 517 * @param local if true, `date' is local wall time; otherwise it 518 * is in GMT time. 519 * @param rawOffset output parameter to receive the raw offset, that 520 * is, the offset not including DST adjustments 521 * @param dstOffset output parameter to receive the DST offset, 522 * that is, the offset to be added to `rawOffset' to obtain the 523 * total offset between local and GMT time. If DST is not in 524 * effect, this value is zero; otherwise it is a positive value, 525 * typically one hour. 526 * @param ec input-output error code 527 * 528 * @stable ICU 2.8 529 */ 530 virtual void getOffset(UDate date, UBool local, int32_t& rawOffset, 531 int32_t& dstOffset, UErrorCode& ec) const; 532 533 /** 534 * Sets the TimeZone's raw GMT offset (i.e., the number of milliseconds to add 535 * to GMT to get local time, before taking daylight savings time into account). 536 * 537 * @param offsetMillis The new raw GMT offset for this time zone. 538 * @stable ICU 2.0 539 */ 540 virtual void setRawOffset(int32_t offsetMillis) = 0; 541 542 /** 543 * Returns the TimeZone's raw GMT offset (i.e., the number of milliseconds to add 544 * to GMT to get local time, before taking daylight savings time into account). 545 * 546 * @return The TimeZone's raw GMT offset. 547 * @stable ICU 2.0 548 */ 549 virtual int32_t getRawOffset(void) const = 0; 550 551 /** 552 * Fills in "ID" with the TimeZone's ID. 553 * 554 * @param ID Receives this TimeZone's ID. 555 * @return A reference to 'ID' 556 * @stable ICU 2.0 557 */ 558 UnicodeString& getID(UnicodeString& ID) const; 559 560 /** 561 * Sets the TimeZone's ID to the specified value. This doesn't affect any other 562 * fields (for example, if you say< 563 * blockquote><pre> 564 * . TimeZone* foo = TimeZone::createTimeZone("America/New_York"); 565 * . foo.setID("America/Los_Angeles"); 566 * </pre>\htmlonly</blockquote>\endhtmlonly 567 * the time zone's GMT offset and daylight-savings rules don't change to those for 568 * Los Angeles. They're still those for New York. Only the ID has changed.) 569 * 570 * @param ID The new time zone ID. 571 * @stable ICU 2.0 572 */ 573 void setID(const UnicodeString& ID); 574 575 /** 576 * Enum for use with getDisplayName 577 * @stable ICU 2.4 578 */ 579 enum EDisplayType { 580 /** 581 * Selector for short display name 582 * @stable ICU 2.4 583 */ 584 SHORT = 1, 585 /** 586 * Selector for long display name 587 * @stable ICU 2.4 588 */ 589 LONG, 590 /** 591 * Selector for short generic display name 592 * @stable ICU 4.4 593 */ 594 SHORT_GENERIC, 595 /** 596 * Selector for long generic display name 597 * @stable ICU 4.4 598 */ 599 LONG_GENERIC, 600 /** 601 * Selector for short display name derived 602 * from time zone offset 603 * @stable ICU 4.4 604 */ 605 SHORT_GMT, 606 /** 607 * Selector for long display name derived 608 * from time zone offset 609 * @stable ICU 4.4 610 */ 611 LONG_GMT, 612 /** 613 * Selector for short display name derived 614 * from the time zone's fallback name 615 * @stable ICU 4.4 616 */ 617 SHORT_COMMONLY_USED, 618 /** 619 * Selector for long display name derived 620 * from the time zone's fallback name 621 * @stable ICU 4.4 622 */ 623 GENERIC_LOCATION 624 }; 625 626 /** 627 * Returns a name of this time zone suitable for presentation to the user 628 * in the default locale. 629 * This method returns the long name, not including daylight savings. 630 * If the display name is not available for the locale, 631 * then this method returns a string in the localized GMT offset format 632 * such as <code>GMT[+-]HH:mm</code>. 633 * @param result the human-readable name of this time zone in the default locale. 634 * @return A reference to 'result'. 635 * @stable ICU 2.0 636 */ 637 UnicodeString& getDisplayName(UnicodeString& result) const; 638 639 /** 640 * Returns a name of this time zone suitable for presentation to the user 641 * in the specified locale. 642 * This method returns the long name, not including daylight savings. 643 * If the display name is not available for the locale, 644 * then this method returns a string in the localized GMT offset format 645 * such as <code>GMT[+-]HH:mm</code>. 646 * @param locale the locale in which to supply the display name. 647 * @param result the human-readable name of this time zone in the given locale 648 * or in the default locale if the given locale is not recognized. 649 * @return A reference to 'result'. 650 * @stable ICU 2.0 651 */ 652 UnicodeString& getDisplayName(const Locale& locale, UnicodeString& result) const; 653 654 /** 655 * Returns a name of this time zone suitable for presentation to the user 656 * in the default locale. 657 * If the display name is not available for the locale, 658 * then this method returns a string in the localized GMT offset format 659 * such as <code>GMT[+-]HH:mm</code>. 660 * @param daylight if true, return the daylight savings name. 661 * @param style 662 * @param result the human-readable name of this time zone in the default locale. 663 * @return A reference to 'result'. 664 * @stable ICU 2.0 665 */ 666 UnicodeString& getDisplayName(UBool daylight, EDisplayType style, UnicodeString& result) const; 667 668 /** 669 * Returns a name of this time zone suitable for presentation to the user 670 * in the specified locale. 671 * If the display name is not available for the locale, 672 * then this method returns a string in the localized GMT offset format 673 * such as <code>GMT[+-]HH:mm</code>. 674 * @param daylight if true, return the daylight savings name. 675 * @param style 676 * @param locale the locale in which to supply the display name. 677 * @param result the human-readable name of this time zone in the given locale 678 * or in the default locale if the given locale is not recognized. 679 * @return A refence to 'result'. 680 * @stable ICU 2.0 681 */ 682 UnicodeString& getDisplayName(UBool daylight, EDisplayType style, const Locale& locale, UnicodeString& result) const; 683 684 /** 685 * Queries if this time zone uses daylight savings time. 686 * @return true if this time zone uses daylight savings time, 687 * false, otherwise. 688 * <p><strong>Note:</strong>The default implementation of 689 * ICU TimeZone uses the tz database, which supports historic 690 * rule changes, for system time zones. With the implementation, 691 * there are time zones that used daylight savings time in the 692 * past, but no longer used currently. For example, Asia/Tokyo has 693 * never used daylight savings time since 1951. Most clients would 694 * expect that this method to return <code>FALSE</code> for such case. 695 * The default implementation of this method returns <code>TRUE</code> 696 * when the time zone uses daylight savings time in the current 697 * (Gregorian) calendar year. 698 * <p>In Java 7, <code>observesDaylightTime()</code> was added in 699 * addition to <code>useDaylightTime()</code>. In Java, <code>useDaylightTime()</code> 700 * only checks if daylight saving time is observed by the last known 701 * rule. This specification might not be what most users would expect 702 * if daylight saving time is currently observed, but not scheduled 703 * in future. In this case, Java's <code>userDaylightTime()</code> returns 704 * <code>false</code>. To resolve the issue, Java 7 added <code>observesDaylightTime()</code>, 705 * which takes the current rule into account. The method <code>observesDaylightTime()</code> 706 * was added in ICU4J for supporting API signature compatibility with JDK. 707 * In general, ICU4C also provides JDK compatible methods, but the current 708 * implementation <code>userDaylightTime()</code> serves the purpose 709 * (takes the current rule into account), <code>observesDaylightTime()</code> 710 * is not added in ICU4C. In addition to <code>useDaylightTime()</code>, ICU4C 711 * <code>BasicTimeZone</code> class (Note that <code>TimeZone::createTimeZone(const UnicodeString &ID)</code> 712 * always returns a <code>BasicTimeZone</code>) provides a series of methods allowing 713 * historic and future time zone rule iteration, so you can check if daylight saving 714 * time is observed or not within a given period. 715 * 716 * @stable ICU 2.0 717 */ 718 virtual UBool useDaylightTime(void) const = 0; 719 720 /** 721 * Queries if the given date is in daylight savings time in 722 * this time zone. 723 * This method is wasteful since it creates a new GregorianCalendar and 724 * deletes it each time it is called. This is a deprecated method 725 * and provided only for Java compatibility. 726 * 727 * @param date the given UDate. 728 * @param status Output param filled in with success/error code. 729 * @return true if the given date is in daylight savings time, 730 * false, otherwise. 731 * @deprecated ICU 2.4. Use Calendar::inDaylightTime() instead. 732 */ 733 virtual UBool inDaylightTime(UDate date, UErrorCode& status) const = 0; 734 735 /** 736 * Returns true if this zone has the same rule and offset as another zone. 737 * That is, if this zone differs only in ID, if at all. 738 * @param other the <code>TimeZone</code> object to be compared with 739 * @return true if the given zone is the same as this one, 740 * with the possible exception of the ID 741 * @stable ICU 2.0 742 */ 743 virtual UBool hasSameRules(const TimeZone& other) const; 744 745 /** 746 * Clones TimeZone objects polymorphically. Clients are responsible for deleting 747 * the TimeZone object cloned. 748 * 749 * @return A new copy of this TimeZone object. 750 * @stable ICU 2.0 751 */ 752 virtual TimeZone* clone(void) const = 0; 753 754 /** 755 * Return the class ID for this class. This is useful only for 756 * comparing to a return value from getDynamicClassID(). 757 * @return The class ID for all objects of this class. 758 * @stable ICU 2.0 759 */ 760 static UClassID U_EXPORT2 getStaticClassID(void); 761 762 /** 763 * Returns a unique class ID POLYMORPHICALLY. This method is to 764 * implement a simple version of RTTI, since not all C++ compilers support genuine 765 * RTTI. Polymorphic operator==() and clone() methods call this method. 766 * <P> 767 * Concrete subclasses of TimeZone must use the UOBJECT_DEFINE_RTTI_IMPLEMENTATION 768 * macro from uobject.h in their implementation to provide correct RTTI information. 769 * @return The class ID for this object. All objects of a given class have the 770 * same class ID. Objects of other classes have different class IDs. 771 * @stable ICU 2.0 772 */ 773 virtual UClassID getDynamicClassID(void) const = 0; 774 775 /** 776 * Returns the amount of time to be added to local standard time 777 * to get local wall clock time. 778 * <p> 779 * The default implementation always returns 3600000 milliseconds 780 * (i.e., one hour) if this time zone observes Daylight Saving 781 * Time. Otherwise, 0 (zero) is returned. 782 * <p> 783 * If an underlying TimeZone implementation subclass supports 784 * historical Daylight Saving Time changes, this method returns 785 * the known latest daylight saving value. 786 * 787 * @return the amount of saving time in milliseconds 788 * @stable ICU 3.6 789 */ 790 virtual int32_t getDSTSavings() const; 791 792 /** 793 * Gets the region code associated with the given 794 * system time zone ID. The region code is either ISO 3166 795 * 2-letter country code or UN M.49 3-digit area code. 796 * When the time zone is not associated with a specific location, 797 * for example - "Etc/UTC", "EST5EDT", then this method returns 798 * "001" (UN M.49 area code for World). 799 * 800 * @param id The system time zone ID. 801 * @param region Output buffer for receiving the region code. 802 * @param capacity The size of the output buffer. 803 * @param status Receives the status. When the given time zone ID 804 * is not a known system time zone ID, 805 * U_ILLEGAL_ARGUMENT_ERROR is set. 806 * @return The length of the output region code. 807 * @stable ICU 4.8 808 */ 809 static int32_t U_EXPORT2 getRegion(const UnicodeString& id, 810 char *region, int32_t capacity, UErrorCode& status); 811 812 protected: 813 814 /** 815 * Default constructor. ID is initialized to the empty string. 816 * @stable ICU 2.0 817 */ 818 TimeZone(); 819 820 /** 821 * Construct a TimeZone with a given ID. 822 * @param id a system time zone ID 823 * @stable ICU 2.0 824 */ 825 TimeZone(const UnicodeString &id); 826 827 /** 828 * Copy constructor. 829 * @param source the object to be copied. 830 * @stable ICU 2.0 831 */ 832 TimeZone(const TimeZone& source); 833 834 /** 835 * Default assignment operator. 836 * @param right the object to be copied. 837 * @stable ICU 2.0 838 */ 839 TimeZone& operator=(const TimeZone& right); 840 841 #ifndef U_HIDE_INTERNAL_API 842 /** 843 * Utility function. For internally loading rule data. 844 * @param top Top resource bundle for tz data 845 * @param ruleid ID of rule to load 846 * @param oldbundle Old bundle to reuse or NULL 847 * @param status Status parameter 848 * @return either a new bundle or *oldbundle 849 * @internal 850 */ 851 static UResourceBundle* loadRule(const UResourceBundle* top, const UnicodeString& ruleid, UResourceBundle* oldbundle, UErrorCode&status); 852 #endif /* U_HIDE_INTERNAL_API */ 853 854 private: 855 friend class ZoneMeta; 856 857 858 static TimeZone* createCustomTimeZone(const UnicodeString&); // Creates a time zone based on the string. 859 860 /** 861 * Finds the given ID in the Olson tzdata. If the given ID is found in the tzdata, 862 * returns the pointer to the ID resource. This method is exposed through ZoneMeta class 863 * for ICU internal implementation and useful for building hashtable using a time zone 864 * ID as a key. 865 * @param id zone id string 866 * @return the pointer of the ID resource, or NULL. 867 */ 868 static const char16_t* findID(const UnicodeString& id); 869 870 /** 871 * Resolve a link in Olson tzdata. When the given id is known and it's not a link, 872 * the id itself is returned. When the given id is known and it is a link, then 873 * dereferenced zone id is returned. When the given id is unknown, then it returns 874 * NULL. 875 * @param id zone id string 876 * @return the dereferenced zone or NULL 877 */ 878 static const char16_t* dereferOlsonLink(const UnicodeString& id); 879 880 /** 881 * Returns the region code associated with the given zone, 882 * or NULL if the zone is not known. 883 * @param id zone id string 884 * @return the region associated with the given zone 885 */ 886 static const char16_t* getRegion(const UnicodeString& id); 887 888 public: 889 #ifndef U_HIDE_INTERNAL_API 890 /** 891 * Returns the region code associated with the given zone, 892 * or NULL if the zone is not known. 893 * @param id zone id string 894 * @param status Status parameter 895 * @return the region associated with the given zone 896 * @internal 897 */ 898 static const char16_t* getRegion(const UnicodeString& id, UErrorCode& status); 899 #endif /* U_HIDE_INTERNAL_API */ 900 901 private: 902 /** 903 * Parses the given custom time zone identifier 904 * @param id id A string of the form GMT[+-]hh:mm, GMT[+-]hhmm, or 905 * GMT[+-]hh. 906 * @param sign Receves parsed sign, 1 for positive, -1 for negative. 907 * @param hour Receives parsed hour field 908 * @param minute Receives parsed minute field 909 * @param second Receives parsed second field 910 * @return Returns TRUE when the given custom id is valid. 911 */ 912 static UBool parseCustomID(const UnicodeString& id, int32_t& sign, int32_t& hour, 913 int32_t& minute, int32_t& second); 914 915 /** 916 * Parse a custom time zone identifier and return the normalized 917 * custom time zone identifier for the given custom id string. 918 * @param id a string of the form GMT[+-]hh:mm, GMT[+-]hhmm, or 919 * GMT[+-]hh. 920 * @param normalized Receives the normalized custom ID 921 * @param status Receives the status. When the input ID string is invalid, 922 * U_ILLEGAL_ARGUMENT_ERROR is set. 923 * @return The normalized custom id string. 924 */ 925 static UnicodeString& getCustomID(const UnicodeString& id, UnicodeString& normalized, 926 UErrorCode& status); 927 928 /** 929 * Returns the normalized custome time zone ID for the given offset fields. 930 * @param hour offset hours 931 * @param min offset minutes 932 * @param sec offset seconds 933 * @param negative sign of the offset, TRUE for negative offset. 934 * @param id Receves the format result (normalized custom ID) 935 * @return The reference to id 936 */ 937 static UnicodeString& formatCustomID(int32_t hour, int32_t min, int32_t sec, 938 UBool negative, UnicodeString& id); 939 940 UnicodeString fID; // this time zone's ID 941 942 friend class TZEnumeration; 943 }; 944 945 946 // ------------------------------------- 947 948 inline UnicodeString& 949 TimeZone::getID(UnicodeString& ID) const 950 { 951 ID = fID; 952 return ID; 953 } 954 955 // ------------------------------------- 956 957 inline void 958 TimeZone::setID(const UnicodeString& ID) 959 { 960 fID = ID; 961 } 962 U_NAMESPACE_END 963 964 #endif /* #if !UCONFIG_NO_FORMATTING */ 965 966 #endif //_TIMEZONE 967 //eof 968
