1 // Copyright (C) 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 * @return A new instance of TimeZone detected from the current host system 288 * configuration. 289 * @stable ICU 55 290 */ 291 static TimeZone* U_EXPORT2 detectHostTimeZone(); 292 293 /** 294 * Creates a new copy of the default TimeZone for this host. Unless the default time 295 * zone has already been set using adoptDefault() or setDefault(), the default is 296 * determined by querying the system using methods in TPlatformUtilities. If the 297 * system routines fail, or if they specify a TimeZone or TimeZone offset which is not 298 * recognized, the TimeZone indicated by the ID kLastResortID is instantiated 299 * and made the default. 300 * 301 * @return A default TimeZone. Clients are responsible for deleting the time zone 302 * object returned. 303 * @stable ICU 2.0 304 */ 305 static TimeZone* U_EXPORT2 createDefault(void); 306 307 /** 308 * Sets the default time zone (i.e., what's returned by createDefault()) to be the 309 * specified time zone. If NULL is specified for the time zone, the default time 310 * zone is set to the default host time zone. This call adopts the TimeZone object 311 * passed in; the client is no longer responsible for deleting it. 312 * 313 * <p>This function is not thread safe. It is an error for multiple threads 314 * to concurrently attempt to set the default time zone, or for any thread 315 * to attempt to reference the default zone while another thread is setting it. 316 * 317 * @param zone A pointer to the new TimeZone object to use as the default. 318 * @stable ICU 2.0 319 */ 320 static void U_EXPORT2 adoptDefault(TimeZone* zone); 321 322 #ifndef U_HIDE_SYSTEM_API 323 /** 324 * Same as adoptDefault(), except that the TimeZone object passed in is NOT adopted; 325 * the caller remains responsible for deleting it. 326 * 327 * <p>See the thread safety note under adoptDefault(). 328 * 329 * @param zone The given timezone. 330 * @system 331 * @stable ICU 2.0 332 */ 333 static void U_EXPORT2 setDefault(const TimeZone& zone); 334 #endif /* U_HIDE_SYSTEM_API */ 335 336 /** 337 * Returns the timezone data version currently used by ICU. 338 * @param status Output param to filled in with a success or an error. 339 * @return the version string, such as "2007f" 340 * @stable ICU 3.8 341 */ 342 static const char* U_EXPORT2 getTZDataVersion(UErrorCode& status); 343 344 /** 345 * Returns the canonical system timezone ID or the normalized 346 * custom time zone ID for the given time zone ID. 347 * @param id The input time zone ID to be canonicalized. 348 * @param canonicalID Receives the canonical system time zone ID 349 * or the custom time zone ID in normalized format. 350 * @param status Receives the status. When the given time zone ID 351 * is neither a known system time zone ID nor a 352 * valid custom time zone ID, U_ILLEGAL_ARGUMENT_ERROR 353 * is set. 354 * @return A reference to the result. 355 * @stable ICU 4.0 356 */ 357 static UnicodeString& U_EXPORT2 getCanonicalID(const UnicodeString& id, 358 UnicodeString& canonicalID, UErrorCode& status); 359 360 /** 361 * Returns the canonical system time zone ID or the normalized 362 * custom time zone ID for the given time zone ID. 363 * @param id The input time zone ID to be canonicalized. 364 * @param canonicalID Receives the canonical system time zone ID 365 * or the custom time zone ID in normalized format. 366 * @param isSystemID Receives if the given ID is a known system 367 * time zone ID. 368 * @param status Receives the status. When the given time zone ID 369 * is neither a known system time zone ID nor a 370 * valid custom time zone ID, U_ILLEGAL_ARGUMENT_ERROR 371 * is set. 372 * @return A reference to the result. 373 * @stable ICU 4.0 374 */ 375 static UnicodeString& U_EXPORT2 getCanonicalID(const UnicodeString& id, 376 UnicodeString& canonicalID, UBool& isSystemID, UErrorCode& status); 377 378 /** 379 * Converts a system time zone ID to an equivalent Windows time zone ID. For example, 380 * Windows time zone ID "Pacific Standard Time" is returned for input "America/Los_Angeles". 381 * 382 * <p>There are system time zones that cannot be mapped to Windows zones. When the input 383 * system time zone ID is unknown or unmappable to a Windows time zone, then the result will be 384 * empty, but the operation itself remains successful (no error status set on return). 385 * 386 * <p>This implementation utilizes <a href="http://unicode.org/cldr/charts/supplemental/zone_tzid.html"> 387 * Zone-Tzid mapping data</a>. The mapping data is updated time to time. To get the latest changes, 388 * please read the ICU user guide section <a href="http://userguide.icu-project.org/datetime/timezone#TOC-Updating-the-Time-Zone-Data"> 389 * Updating the Time Zone Data</a>. 390 * 391 * @param id A system time zone ID. 392 * @param winid Receives a Windows time zone ID. When the input system time zone ID is unknown 393 * or unmappable to a Windows time zone ID, then an empty string is set on return. 394 * @param status Receives the status. 395 * @return A reference to the result (<code>winid</code>). 396 * @see getIDForWindowsID 397 * 398 * @stable ICU 52 399 */ 400 static UnicodeString& U_EXPORT2 getWindowsID(const UnicodeString& id, 401 UnicodeString& winid, UErrorCode& status); 402 403 /** 404 * Converts a Windows time zone ID to an equivalent system time zone ID 405 * for a region. For example, system time zone ID "America/Los_Angeles" is returned 406 * for input Windows ID "Pacific Standard Time" and region "US" (or <code>null</code>), 407 * "America/Vancouver" is returned for the same Windows ID "Pacific Standard Time" and 408 * region "CA". 409 * 410 * <p>Not all Windows time zones can be mapped to system time zones. When the input 411 * Windows time zone ID is unknown or unmappable to a system time zone, then the result 412 * will be empty, but the operation itself remains successful (no error status set on return). 413 * 414 * <p>This implementation utilizes <a href="http://unicode.org/cldr/charts/supplemental/zone_tzid.html"> 415 * Zone-Tzid mapping data</a>. The mapping data is updated time to time. To get the latest changes, 416 * please read the ICU user guide section <a href="http://userguide.icu-project.org/datetime/timezone#TOC-Updating-the-Time-Zone-Data"> 417 * Updating the Time Zone Data</a>. 418 * 419 * @param winid A Windows time zone ID. 420 * @param region A null-terminated region code, or <code>NULL</code> if no regional preference. 421 * @param id Receives a system time zone ID. When the input Windows time zone ID is unknown 422 * or unmappable to a system time zone ID, then an empty string is set on return. 423 * @param status Receives the status. 424 * @return A reference to the result (<code>id</code>). 425 * @see getWindowsID 426 * 427 * @stable ICU 52 428 */ 429 static UnicodeString& U_EXPORT2 getIDForWindowsID(const UnicodeString& winid, const char* region, 430 UnicodeString& id, UErrorCode& status); 431 432 /** 433 * Returns true if the two TimeZones are equal. (The TimeZone version only compares 434 * IDs, but subclasses are expected to also compare the fields they add.) 435 * 436 * @param that The TimeZone object to be compared with. 437 * @return True if the given TimeZone is equal to this TimeZone; false 438 * otherwise. 439 * @stable ICU 2.0 440 */ 441 virtual UBool operator==(const TimeZone& that) const; 442 443 /** 444 * Returns true if the two TimeZones are NOT equal; that is, if operator==() returns 445 * false. 446 * 447 * @param that The TimeZone object to be compared with. 448 * @return True if the given TimeZone is not equal to this TimeZone; false 449 * otherwise. 450 * @stable ICU 2.0 451 */ 452 UBool operator!=(const TimeZone& that) const {return !operator==(that);} 453 454 /** 455 * Returns the TimeZone's adjusted GMT offset (i.e., the number of milliseconds to add 456 * to GMT to get local time in this time zone, taking daylight savings time into 457 * account) as of a particular reference date. The reference date is used to determine 458 * whether daylight savings time is in effect and needs to be figured into the offset 459 * that is returned (in other words, what is the adjusted GMT offset in this time zone 460 * at this particular date and time?). For the time zones produced by createTimeZone(), 461 * the reference data is specified according to the Gregorian calendar, and the date 462 * and time fields are local standard time. 463 * 464 * <p>Note: Don't call this method. Instead, call the getOffset(UDate...) overload, 465 * which returns both the raw and the DST offset for a given time. This method 466 * is retained only for backward compatibility. 467 * 468 * @param era The reference date's era 469 * @param year The reference date's year 470 * @param month The reference date's month (0-based; 0 is January) 471 * @param day The reference date's day-in-month (1-based) 472 * @param dayOfWeek The reference date's day-of-week (1-based; 1 is Sunday) 473 * @param millis The reference date's milliseconds in day, local standard time 474 * @param status Output param to filled in with a success or an error. 475 * @return The offset in milliseconds to add to GMT to get local time. 476 * @stable ICU 2.0 477 */ 478 virtual int32_t getOffset(uint8_t era, int32_t year, int32_t month, int32_t day, 479 uint8_t dayOfWeek, int32_t millis, UErrorCode& status) const = 0; 480 481 /** 482 * Gets the time zone offset, for current date, modified in case of 483 * daylight savings. This is the offset to add *to* UTC to get local time. 484 * 485 * <p>Note: Don't call this method. Instead, call the getOffset(UDate...) overload, 486 * which returns both the raw and the DST offset for a given time. This method 487 * is retained only for backward compatibility. 488 * 489 * @param era the era of the given date. 490 * @param year the year in the given date. 491 * @param month the month in the given date. 492 * Month is 0-based. e.g., 0 for January. 493 * @param day the day-in-month of the given date. 494 * @param dayOfWeek the day-of-week of the given date. 495 * @param milliseconds the millis in day in <em>standard</em> local time. 496 * @param monthLength the length of the given month in days. 497 * @param status Output param to filled in with a success or an error. 498 * @return the offset to add *to* GMT to get local time. 499 * @stable ICU 2.0 500 */ 501 virtual int32_t getOffset(uint8_t era, int32_t year, int32_t month, int32_t day, 502 uint8_t dayOfWeek, int32_t milliseconds, 503 int32_t monthLength, UErrorCode& status) const = 0; 504 505 /** 506 * Returns the time zone raw and GMT offset for the given moment 507 * in time. Upon return, local-millis = GMT-millis + rawOffset + 508 * dstOffset. All computations are performed in the proleptic 509 * Gregorian calendar. The default implementation in the TimeZone 510 * class delegates to the 8-argument getOffset(). 511 * 512 * @param date moment in time for which to return offsets, in 513 * units of milliseconds from January 1, 1970 0:00 GMT, either GMT 514 * time or local wall time, depending on `local'. 515 * @param local if true, `date' is local wall time; otherwise it 516 * is in GMT time. 517 * @param rawOffset output parameter to receive the raw offset, that 518 * is, the offset not including DST adjustments 519 * @param dstOffset output parameter to receive the DST offset, 520 * that is, the offset to be added to `rawOffset' to obtain the 521 * total offset between local and GMT time. If DST is not in 522 * effect, this value is zero; otherwise it is a positive value, 523 * typically one hour. 524 * @param ec input-output error code 525 * 526 * @stable ICU 2.8 527 */ 528 virtual void getOffset(UDate date, UBool local, int32_t& rawOffset, 529 int32_t& dstOffset, UErrorCode& ec) const; 530 531 /** 532 * Sets the TimeZone's raw GMT offset (i.e., the number of milliseconds to add 533 * to GMT to get local time, before taking daylight savings time into account). 534 * 535 * @param offsetMillis The new raw GMT offset for this time zone. 536 * @stable ICU 2.0 537 */ 538 virtual void setRawOffset(int32_t offsetMillis) = 0; 539 540 /** 541 * Returns the TimeZone's raw GMT offset (i.e., the number of milliseconds to add 542 * to GMT to get local time, before taking daylight savings time into account). 543 * 544 * @return The TimeZone's raw GMT offset. 545 * @stable ICU 2.0 546 */ 547 virtual int32_t getRawOffset(void) const = 0; 548 549 /** 550 * Fills in "ID" with the TimeZone's ID. 551 * 552 * @param ID Receives this TimeZone's ID. 553 * @return A reference to 'ID' 554 * @stable ICU 2.0 555 */ 556 UnicodeString& getID(UnicodeString& ID) const; 557 558 /** 559 * Sets the TimeZone's ID to the specified value. This doesn't affect any other 560 * fields (for example, if you say< 561 * blockquote><pre> 562 * . TimeZone* foo = TimeZone::createTimeZone("America/New_York"); 563 * . foo.setID("America/Los_Angeles"); 564 * </pre>\htmlonly</blockquote>\endhtmlonly 565 * the time zone's GMT offset and daylight-savings rules don't change to those for 566 * Los Angeles. They're still those for New York. Only the ID has changed.) 567 * 568 * @param ID The new time zone ID. 569 * @stable ICU 2.0 570 */ 571 void setID(const UnicodeString& ID); 572 573 /** 574 * Enum for use with getDisplayName 575 * @stable ICU 2.4 576 */ 577 enum EDisplayType { 578 /** 579 * Selector for short display name 580 * @stable ICU 2.4 581 */ 582 SHORT = 1, 583 /** 584 * Selector for long display name 585 * @stable ICU 2.4 586 */ 587 LONG, 588 /** 589 * Selector for short generic display name 590 * @stable ICU 4.4 591 */ 592 SHORT_GENERIC, 593 /** 594 * Selector for long generic display name 595 * @stable ICU 4.4 596 */ 597 LONG_GENERIC, 598 /** 599 * Selector for short display name derived 600 * from time zone offset 601 * @stable ICU 4.4 602 */ 603 SHORT_GMT, 604 /** 605 * Selector for long display name derived 606 * from time zone offset 607 * @stable ICU 4.4 608 */ 609 LONG_GMT, 610 /** 611 * Selector for short display name derived 612 * from the time zone's fallback name 613 * @stable ICU 4.4 614 */ 615 SHORT_COMMONLY_USED, 616 /** 617 * Selector for long display name derived 618 * from the time zone's fallback name 619 * @stable ICU 4.4 620 */ 621 GENERIC_LOCATION 622 }; 623 624 /** 625 * Returns a name of this time zone suitable for presentation to the user 626 * in the default locale. 627 * This method returns the long name, not including daylight savings. 628 * If the display name is not available for the locale, 629 * then this method returns a string in the localized GMT offset format 630 * such as <code>GMT[+-]HH:mm</code>. 631 * @param result the human-readable name of this time zone in the default locale. 632 * @return A reference to 'result'. 633 * @stable ICU 2.0 634 */ 635 UnicodeString& getDisplayName(UnicodeString& result) const; 636 637 /** 638 * Returns a name of this time zone suitable for presentation to the user 639 * in the specified locale. 640 * This method returns the long name, not including daylight savings. 641 * If the display name is not available for the locale, 642 * then this method returns a string in the localized GMT offset format 643 * such as <code>GMT[+-]HH:mm</code>. 644 * @param locale the locale in which to supply the display name. 645 * @param result the human-readable name of this time zone in the given locale 646 * or in the default locale if the given locale is not recognized. 647 * @return A reference to 'result'. 648 * @stable ICU 2.0 649 */ 650 UnicodeString& getDisplayName(const Locale& locale, UnicodeString& result) const; 651 652 /** 653 * Returns a name of this time zone suitable for presentation to the user 654 * in the default locale. 655 * If the display name is not available for the locale, 656 * then this method returns a string in the localized GMT offset format 657 * such as <code>GMT[+-]HH:mm</code>. 658 * @param daylight if true, return the daylight savings name. 659 * @param style 660 * @param result the human-readable name of this time zone in the default locale. 661 * @return A reference to 'result'. 662 * @stable ICU 2.0 663 */ 664 UnicodeString& getDisplayName(UBool daylight, EDisplayType style, UnicodeString& result) const; 665 666 /** 667 * Returns a name of this time zone suitable for presentation to the user 668 * in the specified locale. 669 * If the display name is not available for the locale, 670 * then this method returns a string in the localized GMT offset format 671 * such as <code>GMT[+-]HH:mm</code>. 672 * @param daylight if true, return the daylight savings name. 673 * @param style 674 * @param locale the locale in which to supply the display name. 675 * @param result the human-readable name of this time zone in the given locale 676 * or in the default locale if the given locale is not recognized. 677 * @return A refence to 'result'. 678 * @stable ICU 2.0 679 */ 680 UnicodeString& getDisplayName(UBool daylight, EDisplayType style, const Locale& locale, UnicodeString& result) const; 681 682 /** 683 * Queries if this time zone uses daylight savings time. 684 * @return true if this time zone uses daylight savings time, 685 * false, otherwise. 686 * <p><strong>Note:</strong>The default implementation of 687 * ICU TimeZone uses the tz database, which supports historic 688 * rule changes, for system time zones. With the implementation, 689 * there are time zones that used daylight savings time in the 690 * past, but no longer used currently. For example, Asia/Tokyo has 691 * never used daylight savings time since 1951. Most clients would 692 * expect that this method to return <code>FALSE</code> for such case. 693 * The default implementation of this method returns <code>TRUE</code> 694 * when the time zone uses daylight savings time in the current 695 * (Gregorian) calendar year. 696 * <p>In Java 7, <code>observesDaylightTime()</code> was added in 697 * addition to <code>useDaylightTime()</code>. In Java, <code>useDaylightTime()</code> 698 * only checks if daylight saving time is observed by the last known 699 * rule. This specification might not be what most users would expect 700 * if daylight saving time is currently observed, but not scheduled 701 * in future. In this case, Java's <code>userDaylightTime()</code> returns 702 * <code>false</code>. To resolve the issue, Java 7 added <code>observesDaylightTime()</code>, 703 * which takes the current rule into account. The method <code>observesDaylightTime()</code> 704 * was added in ICU4J for supporting API signature compatibility with JDK. 705 * In general, ICU4C also provides JDK compatible methods, but the current 706 * implementation <code>userDaylightTime()</code> serves the purpose 707 * (takes the current rule into account), <code>observesDaylightTime()</code> 708 * is not added in ICU4C. In addition to <code>useDaylightTime()</code>, ICU4C 709 * <code>BasicTimeZone</code> class (Note that <code>TimeZone::createTimeZone(const UnicodeString &ID)</code> 710 * always returns a <code>BasicTimeZone</code>) provides a series of methods allowing 711 * historic and future time zone rule iteration, so you can check if daylight saving 712 * time is observed or not within a given period. 713 * 714 * @stable ICU 2.0 715 */ 716 virtual UBool useDaylightTime(void) const = 0; 717 718 /** 719 * Queries if the given date is in daylight savings time in 720 * this time zone. 721 * This method is wasteful since it creates a new GregorianCalendar and 722 * deletes it each time it is called. This is a deprecated method 723 * and provided only for Java compatibility. 724 * 725 * @param date the given UDate. 726 * @param status Output param filled in with success/error code. 727 * @return true if the given date is in daylight savings time, 728 * false, otherwise. 729 * @deprecated ICU 2.4. Use Calendar::inDaylightTime() instead. 730 */ 731 virtual UBool inDaylightTime(UDate date, UErrorCode& status) const = 0; 732 733 /** 734 * Returns true if this zone has the same rule and offset as another zone. 735 * That is, if this zone differs only in ID, if at all. 736 * @param other the <code>TimeZone</code> object to be compared with 737 * @return true if the given zone is the same as this one, 738 * with the possible exception of the ID 739 * @stable ICU 2.0 740 */ 741 virtual UBool hasSameRules(const TimeZone& other) const; 742 743 /** 744 * Clones TimeZone objects polymorphically. Clients are responsible for deleting 745 * the TimeZone object cloned. 746 * 747 * @return A new copy of this TimeZone object. 748 * @stable ICU 2.0 749 */ 750 virtual TimeZone* clone(void) const = 0; 751 752 /** 753 * Return the class ID for this class. This is useful only for 754 * comparing to a return value from getDynamicClassID(). 755 * @return The class ID for all objects of this class. 756 * @stable ICU 2.0 757 */ 758 static UClassID U_EXPORT2 getStaticClassID(void); 759 760 /** 761 * Returns a unique class ID POLYMORPHICALLY. This method is to 762 * implement a simple version of RTTI, since not all C++ compilers support genuine 763 * RTTI. Polymorphic operator==() and clone() methods call this method. 764 * <P> 765 * Concrete subclasses of TimeZone must use the UOBJECT_DEFINE_RTTI_IMPLEMENTATION 766 * macro from uobject.h in their implementation to provide correct RTTI information. 767 * @return The class ID for this object. All objects of a given class have the 768 * same class ID. Objects of other classes have different class IDs. 769 * @stable ICU 2.0 770 */ 771 virtual UClassID getDynamicClassID(void) const = 0; 772 773 /** 774 * Returns the amount of time to be added to local standard time 775 * to get local wall clock time. 776 * <p> 777 * The default implementation always returns 3600000 milliseconds 778 * (i.e., one hour) if this time zone observes Daylight Saving 779 * Time. Otherwise, 0 (zero) is returned. 780 * <p> 781 * If an underlying TimeZone implementation subclass supports 782 * historical Daylight Saving Time changes, this method returns 783 * the known latest daylight saving value. 784 * 785 * @return the amount of saving time in milliseconds 786 * @stable ICU 3.6 787 */ 788 virtual int32_t getDSTSavings() const; 789 790 /** 791 * Gets the region code associated with the given 792 * system time zone ID. The region code is either ISO 3166 793 * 2-letter country code or UN M.49 3-digit area code. 794 * When the time zone is not associated with a specific location, 795 * for example - "Etc/UTC", "EST5EDT", then this method returns 796 * "001" (UN M.49 area code for World). 797 * 798 * @param id The system time zone ID. 799 * @param region Output buffer for receiving the region code. 800 * @param capacity The size of the output buffer. 801 * @param status Receives the status. When the given time zone ID 802 * is not a known system time zone ID, 803 * U_ILLEGAL_ARGUMENT_ERROR is set. 804 * @return The length of the output region code. 805 * @stable ICU 4.8 806 */ 807 static int32_t U_EXPORT2 getRegion(const UnicodeString& id, 808 char *region, int32_t capacity, UErrorCode& status); 809 810 protected: 811 812 /** 813 * Default constructor. ID is initialized to the empty string. 814 * @stable ICU 2.0 815 */ 816 TimeZone(); 817 818 /** 819 * Construct a TimeZone with a given ID. 820 * @param id a system time zone ID 821 * @stable ICU 2.0 822 */ 823 TimeZone(const UnicodeString &id); 824 825 /** 826 * Copy constructor. 827 * @param source the object to be copied. 828 * @stable ICU 2.0 829 */ 830 TimeZone(const TimeZone& source); 831 832 /** 833 * Default assignment operator. 834 * @param right the object to be copied. 835 * @stable ICU 2.0 836 */ 837 TimeZone& operator=(const TimeZone& right); 838 839 #ifndef U_HIDE_INTERNAL_API 840 /** 841 * Utility function. For internally loading rule data. 842 * @param top Top resource bundle for tz data 843 * @param ruleid ID of rule to load 844 * @param oldbundle Old bundle to reuse or NULL 845 * @param status Status parameter 846 * @return either a new bundle or *oldbundle 847 * @internal 848 */ 849 static UResourceBundle* loadRule(const UResourceBundle* top, const UnicodeString& ruleid, UResourceBundle* oldbundle, UErrorCode&status); 850 #endif /* U_HIDE_INTERNAL_API */ 851 852 private: 853 friend class ZoneMeta; 854 855 856 static TimeZone* createCustomTimeZone(const UnicodeString&); // Creates a time zone based on the string. 857 858 /** 859 * Finds the given ID in the Olson tzdata. If the given ID is found in the tzdata, 860 * returns the pointer to the ID resource. This method is exposed through ZoneMeta class 861 * for ICU internal implementation and useful for building hashtable using a time zone 862 * ID as a key. 863 * @param id zone id string 864 * @return the pointer of the ID resource, or NULL. 865 */ 866 static const UChar* findID(const UnicodeString& id); 867 868 /** 869 * Resolve a link in Olson tzdata. When the given id is known and it's not a link, 870 * the id itself is returned. When the given id is known and it is a link, then 871 * dereferenced zone id is returned. When the given id is unknown, then it returns 872 * NULL. 873 * @param id zone id string 874 * @return the dereferenced zone or NULL 875 */ 876 static const UChar* dereferOlsonLink(const UnicodeString& id); 877 878 /** 879 * Returns the region code associated with the given zone, 880 * or NULL if the zone is not known. 881 * @param id zone id string 882 * @return the region associated with the given zone 883 */ 884 static const UChar* getRegion(const UnicodeString& id); 885 886 public: 887 #ifndef U_HIDE_INTERNAL_API 888 /** 889 * Returns the region code associated with the given zone, 890 * or NULL if the zone is not known. 891 * @param id zone id string 892 * @param status Status parameter 893 * @return the region associated with the given zone 894 * @internal 895 */ 896 static const UChar* getRegion(const UnicodeString& id, UErrorCode& status); 897 #endif /* U_HIDE_INTERNAL_API */ 898 899 private: 900 /** 901 * Parses the given custom time zone identifier 902 * @param id id A string of the form GMT[+-]hh:mm, GMT[+-]hhmm, or 903 * GMT[+-]hh. 904 * @param sign Receves parsed sign, 1 for positive, -1 for negative. 905 * @param hour Receives parsed hour field 906 * @param minute Receives parsed minute field 907 * @param second Receives parsed second field 908 * @return Returns TRUE when the given custom id is valid. 909 */ 910 static UBool parseCustomID(const UnicodeString& id, int32_t& sign, int32_t& hour, 911 int32_t& minute, int32_t& second); 912 913 /** 914 * Parse a custom time zone identifier and return the normalized 915 * custom time zone identifier for the given custom id string. 916 * @param id a string of the form GMT[+-]hh:mm, GMT[+-]hhmm, or 917 * GMT[+-]hh. 918 * @param normalized Receives the normalized custom ID 919 * @param status Receives the status. When the input ID string is invalid, 920 * U_ILLEGAL_ARGUMENT_ERROR is set. 921 * @return The normalized custom id string. 922 */ 923 static UnicodeString& getCustomID(const UnicodeString& id, UnicodeString& normalized, 924 UErrorCode& status); 925 926 /** 927 * Returns the normalized custome time zone ID for the given offset fields. 928 * @param hour offset hours 929 * @param min offset minutes 930 * @param sec offset seconds 931 * @param negative sign of the offset, TRUE for negative offset. 932 * @param id Receves the format result (normalized custom ID) 933 * @return The reference to id 934 */ 935 static UnicodeString& formatCustomID(int32_t hour, int32_t min, int32_t sec, 936 UBool negative, UnicodeString& id); 937 938 UnicodeString fID; // this time zone's ID 939 940 friend class TZEnumeration; 941 }; 942 943 944 // ------------------------------------- 945 946 inline UnicodeString& 947 TimeZone::getID(UnicodeString& ID) const 948 { 949 ID = fID; 950 return ID; 951 } 952 953 // ------------------------------------- 954 955 inline void 956 TimeZone::setID(const UnicodeString& ID) 957 { 958 fID = ID; 959 } 960 U_NAMESPACE_END 961 962 #endif /* #if !UCONFIG_NO_FORMATTING */ 963 964 #endif //_TIMEZONE 965 //eof 966
