/************************************************************************* * Copyright (c) 1997-2015, International Business Machines Corporation * and others. All Rights Reserved. ************************************************************************** * * File TIMEZONE.H * * Modification History: * * Date Name Description * 04/21/97 aliu Overhauled header. * 07/09/97 helena Changed createInstance to createDefault. * 08/06/97 aliu Removed dependency on internal header for Hashtable. * 08/10/98 stephen Changed getDisplayName() API conventions to match * 08/19/98 stephen Changed createTimeZone() to never return 0 * 09/02/98 stephen Sync to JDK 1.2 8/31 * - Added getOffset(... monthlen ...) * - Added hasSameRules() * 09/15/98 stephen Added getStaticClassID * 12/03/99 aliu Moved data out of static table into icudata.dll. * Hashtable replaced by new static data structures. * 12/14/99 aliu Made GMT public. * 08/15/01 grhoten Made GMT private and added the getGMT() function ************************************************************************** */ #ifndef TIMEZONE_H #define TIMEZONE_H #include "unicode/utypes.h" /** * \file * \brief C++ API: TimeZone object */ #if !UCONFIG_NO_FORMATTING #include "unicode/uobject.h" #include "unicode/unistr.h" #include "unicode/ures.h" #include "unicode/ucal.h" U_NAMESPACE_BEGIN class StringEnumeration; /** * * <code>TimeZone</code> represents a time zone offset, and also figures out daylight * savings. * * <p> * Typically, you get a <code>TimeZone</code> using <code>createDefault</code> * which creates a <code>TimeZone</code> based on the time zone where the program * is running. For example, for a program running in Japan, <code>createDefault</code> * creates a <code>TimeZone</code> object based on Japanese Standard Time. * * <p> * You can also get a <code>TimeZone</code> using <code>createTimeZone</code> along * with a time zone ID. For instance, the time zone ID for the US Pacific * Time zone is "America/Los_Angeles". So, you can get a Pacific Time <code>TimeZone</code> object * with: * \htmlonly<blockquote>\endhtmlonly * <pre> * TimeZone *tz = TimeZone::createTimeZone("America/Los_Angeles"); * </pre> * \htmlonly</blockquote>\endhtmlonly * You can use <code>getAvailableIDs</code> method to iterate through * all the supported time zone IDs, or getCanonicalID method to check * if a time zone ID is supported or not. You can then choose a * supported ID to get a <code>TimeZone</code>. * If the time zone you want is not represented by one of the * supported IDs, then you can create a custom time zone ID with * the following syntax: * * \htmlonly<blockquote>\endhtmlonly * <pre> * GMT[+|-]hh[[:]mm] * </pre> * \htmlonly</blockquote>\endhtmlonly * * For example, you might specify GMT+14:00 as a custom * time zone ID. The <code>TimeZone</code> that is returned * when you specify a custom time zone ID uses the specified * offset from GMT(=UTC) and does not observe daylight saving * time. For example, you might specify GMT+14:00 as a custom * time zone ID to create a TimeZone representing 14 hours ahead * of GMT (with no daylight saving time). In addition, * <code>getCanonicalID</code> can also be used to * normalize a custom time zone ID. * * TimeZone is an abstract class representing a time zone. A TimeZone is needed for * Calendar to produce local time for a particular time zone. A TimeZone comprises * three basic pieces of information: * <ul> * <li>A time zone offset; that, is the number of milliseconds to add or subtract * from a time expressed in terms of GMT to convert it to the same time in that * time zone (without taking daylight savings time into account).</li> * <li>Logic necessary to take daylight savings time into account if daylight savings * time is observed in that time zone (e.g., the days and hours on which daylight * savings time begins and ends).</li> * <li>An ID. This is a text string that uniquely identifies the time zone.</li> * </ul> * * (Only the ID is actually implemented in TimeZone; subclasses of TimeZone may handle * daylight savings time and GMT offset in different ways. Currently we have the following * TimeZone subclasses: RuleBasedTimeZone, SimpleTimeZone, and VTimeZone.) * <P> * The TimeZone class contains a static list containing a TimeZone object for every * combination of GMT offset and daylight-savings time rules currently in use in the * world, each with a unique ID. Each ID consists of a region (usually a continent or * ocean) and a city in that region, separated by a slash, (for example, US Pacific * Time is "America/Los_Angeles.") Because older versions of this class used * three- or four-letter abbreviations instead, there is also a table that maps the older * abbreviations to the newer ones (for example, "PST" maps to "America/Los_Angeles"). * Anywhere the API requires an ID, you can use either form. * <P> * To create a new TimeZone, you call the factory function TimeZone::createTimeZone() * and pass it a time zone ID. You can use the createEnumeration() function to * obtain a list of all the time zone IDs recognized by createTimeZone(). * <P> * You can also use TimeZone::createDefault() to create a TimeZone. This function uses * platform-specific APIs to produce a TimeZone for the time zone corresponding to * the client's computer's physical location. For example, if you're in Japan (assuming * your machine is set up correctly), TimeZone::createDefault() will return a TimeZone * for Japanese Standard Time ("Asia/Tokyo"). */ class U_I18N_API TimeZone : public UObject { public: /** * @stable ICU 2.0 */ virtual ~TimeZone(); /** * Returns the "unknown" time zone. * It behaves like the GMT/UTC time zone but has the * <code>UCAL_UNKNOWN_ZONE_ID</code> = "Etc/Unknown". * createTimeZone() returns a mutable clone of this time zone if the input ID is not recognized. * * @return the "unknown" time zone. * @see UCAL_UNKNOWN_ZONE_ID * @see createTimeZone * @see getGMT * @stable ICU 49 */ static const TimeZone& U_EXPORT2 getUnknown(); /** * The GMT (=UTC) time zone has a raw offset of zero and does not use daylight * savings time. This is a commonly used time zone. * * <p>Note: For backward compatibility reason, the ID used by the time * zone returned by this method is "GMT", although the ICU's canonical * ID for the GMT time zone is "Etc/GMT". * * @return the GMT/UTC time zone. * @see getUnknown * @stable ICU 2.0 */ static const TimeZone* U_EXPORT2 getGMT(void); /** * Creates a <code>TimeZone</code> for the given ID. * @param ID the ID for a <code>TimeZone</code>, such as "America/Los_Angeles", * or a custom ID such as "GMT-8:00". * @return the specified <code>TimeZone</code>, or a mutable clone of getUnknown() * if the given ID cannot be understood or if the given ID is "Etc/Unknown". * The return result is guaranteed to be non-NULL. * If you require that the specific zone asked for be returned, * compare the result with getUnknown() or check the ID of the return result. * @stable ICU 2.0 */ static TimeZone* U_EXPORT2 createTimeZone(const UnicodeString& ID); /** * Returns an enumeration over system time zone IDs with the given * filter conditions. * @param zoneType The system time zone type. * @param region The ISO 3166 two-letter country code or UN M.49 * three-digit area code. When NULL, no filtering * done by region. * @param rawOffset An offset from GMT in milliseconds, ignoring * the effect of daylight savings time, if any. * When NULL, no filtering done by zone offset. * @param ec Output param to filled in with a success or * an error. * @return an enumeration object, owned by the caller. * @stable ICU 4.8 */ static StringEnumeration* U_EXPORT2 createTimeZoneIDEnumeration( USystemTimeZoneType zoneType, const char* region, const int32_t* rawOffset, UErrorCode& ec); /** * Returns an enumeration over all recognized time zone IDs. (i.e., * all strings that createTimeZone() accepts) * * @return an enumeration object, owned by the caller. * @stable ICU 2.4 */ static StringEnumeration* U_EXPORT2 createEnumeration(); /** * Returns an enumeration over time zone IDs with a given raw * offset from GMT. There may be several times zones with the * same GMT offset that differ in the way they handle daylight * savings time. For example, the state of Arizona doesn't * observe daylight savings time. If you ask for the time zone * IDs corresponding to GMT-7:00, you'll get back an enumeration * over two time zone IDs: "America/Denver," which corresponds to * Mountain Standard Time in the winter and Mountain Daylight Time * in the summer, and "America/Phoenix", which corresponds to * Mountain Standard Time year-round, even in the summer. * * @param rawOffset an offset from GMT in milliseconds, ignoring * the effect of daylight savings time, if any * @return an enumeration object, owned by the caller * @stable ICU 2.4 */ static StringEnumeration* U_EXPORT2 createEnumeration(int32_t rawOffset); /** * Returns an enumeration over time zone IDs associated with the * given country. Some zones are affiliated with no country * (e.g., "UTC"); these may also be retrieved, as a group. * * @param country The ISO 3166 two-letter country code, or NULL to * retrieve zones not affiliated with any country. * @return an enumeration object, owned by the caller * @stable ICU 2.4 */ static StringEnumeration* U_EXPORT2 createEnumeration(const char* country); /** * Returns the number of IDs in the equivalency group that * includes the given ID. An equivalency group contains zones * that have the same GMT offset and rules. * * <p>The returned count includes the given ID; it is always >= 1. * The given ID must be a system time zone. If it is not, returns * zero. * @param id a system time zone ID * @return the number of zones in the equivalency group containing * 'id', or zero if 'id' is not a valid system ID * @see #getEquivalentID * @stable ICU 2.0 */ static int32_t U_EXPORT2 countEquivalentIDs(const UnicodeString& id); /** * Returns an ID in the equivalency group that * includes the given ID. An equivalency group contains zones * that have the same GMT offset and rules. * * <p>The given index must be in the range 0..n-1, where n is the * value returned by <code>countEquivalentIDs(id)</code>. For * some value of 'index', the returned value will be equal to the * given id. If the given id is not a valid system time zone, or * if 'index' is out of range, then returns an empty string. * @param id a system time zone ID * @param index a value from 0 to n-1, where n is the value * returned by <code>countEquivalentIDs(id)</code> * @return the ID of the index-th zone in the equivalency group * containing 'id', or an empty string if 'id' is not a valid * system ID or 'index' is out of range * @see #countEquivalentIDs * @stable ICU 2.0 */ static const UnicodeString U_EXPORT2 getEquivalentID(const UnicodeString& id, int32_t index); #ifndef U_HIDE_DRAFT_API /** * Creates an instance of TimeZone detected from the current host * system configuration. Note that ICU4C does not change the default * time zone unless TimeZone::adoptDefault(TimeZone*) or * TimeZone::setDefault(const TimeZone&) is explicitly called by a * user. This method does not update the current ICU's default, * and may return a different TimeZone from the one returned by * TimeZone::createDefault(). * * @return A new instance of TimeZone detected from the current host system * configuration. * @draft ICU 55 */ static TimeZone* U_EXPORT2 detectHostTimeZone(); #endif /** * Creates a new copy of the default TimeZone for this host. Unless the default time * zone has already been set using adoptDefault() or setDefault(), the default is * determined by querying the system using methods in TPlatformUtilities. If the * system routines fail, or if they specify a TimeZone or TimeZone offset which is not * recognized, the TimeZone indicated by the ID kLastResortID is instantiated * and made the default. * * @return A default TimeZone. Clients are responsible for deleting the time zone * object returned. * @stable ICU 2.0 */ static TimeZone* U_EXPORT2 createDefault(void); /** * Sets the default time zone (i.e., what's returned by createDefault()) to be the * specified time zone. If NULL is specified for the time zone, the default time * zone is set to the default host time zone. This call adopts the TimeZone object * passed in; the client is no longer responsible for deleting it. * * <p>This function is not thread safe. It is an error for multiple threads * to concurrently attempt to set the default time zone, or for any thread * to attempt to reference the default zone while another thread is setting it. * * @param zone A pointer to the new TimeZone object to use as the default. * @stable ICU 2.0 */ static void U_EXPORT2 adoptDefault(TimeZone* zone); #ifndef U_HIDE_SYSTEM_API /** * Same as adoptDefault(), except that the TimeZone object passed in is NOT adopted; * the caller remains responsible for deleting it. * * <p>See the thread safety note under adoptDefault(). * * @param zone The given timezone. * @system * @stable ICU 2.0 */ static void U_EXPORT2 setDefault(const TimeZone& zone); #endif /* U_HIDE_SYSTEM_API */ /** * Returns the timezone data version currently used by ICU. * @param status Output param to filled in with a success or an error. * @return the version string, such as "2007f" * @stable ICU 3.8 */ static const char* U_EXPORT2 getTZDataVersion(UErrorCode& status); /** * Returns the canonical system timezone ID or the normalized * custom time zone ID for the given time zone ID. * @param id The input time zone ID to be canonicalized. * @param canonicalID Receives the canonical system time zone ID * or the custom time zone ID in normalized format. * @param status Receives the status. When the given time zone ID * is neither a known system time zone ID nor a * valid custom time zone ID, U_ILLEGAL_ARGUMENT_ERROR * is set. * @return A reference to the result. * @stable ICU 4.0 */ static UnicodeString& U_EXPORT2 getCanonicalID(const UnicodeString& id, UnicodeString& canonicalID, UErrorCode& status); /** * Returns the canonical system time zone ID or the normalized * custom time zone ID for the given time zone ID. * @param id The input time zone ID to be canonicalized. * @param canonicalID Receives the canonical system time zone ID * or the custom time zone ID in normalized format. * @param isSystemID Receives if the given ID is a known system * time zone ID. * @param status Receives the status. When the given time zone ID * is neither a known system time zone ID nor a * valid custom time zone ID, U_ILLEGAL_ARGUMENT_ERROR * is set. * @return A reference to the result. * @stable ICU 4.0 */ static UnicodeString& U_EXPORT2 getCanonicalID(const UnicodeString& id, UnicodeString& canonicalID, UBool& isSystemID, UErrorCode& status); /** * Converts a system time zone ID to an equivalent Windows time zone ID. For example, * Windows time zone ID "Pacific Standard Time" is returned for input "America/Los_Angeles". * * <p>There are system time zones that cannot be mapped to Windows zones. When the input * system time zone ID is unknown or unmappable to a Windows time zone, then the result will be * empty, but the operation itself remains successful (no error status set on return). * * <p>This implementation utilizes <a href="http://unicode.org/cldr/charts/supplemental/zone_tzid.html"> * Zone-Tzid mapping data</a>. The mapping data is updated time to time. To get the latest changes, * please read the ICU user guide section <a href="http://userguide.icu-project.org/datetime/timezone#TOC-Updating-the-Time-Zone-Data"> * Updating the Time Zone Data</a>. * * @param id A system time zone ID. * @param winid Receives a Windows time zone ID. When the input system time zone ID is unknown * or unmappable to a Windows time zone ID, then an empty string is set on return. * @param status Receives the status. * @return A reference to the result (<code>winid</code>). * @see getIDForWindowsID * * @stable ICU 52 */ static UnicodeString& U_EXPORT2 getWindowsID(const UnicodeString& id, UnicodeString& winid, UErrorCode& status); /** * Converts a Windows time zone ID to an equivalent system time zone ID * for a region. For example, system time zone ID "America/Los_Angeles" is returned * for input Windows ID "Pacific Standard Time" and region "US" (or <code>null</code>), * "America/Vancouver" is returned for the same Windows ID "Pacific Standard Time" and * region "CA". * * <p>Not all Windows time zones can be mapped to system time zones. When the input * Windows time zone ID is unknown or unmappable to a system time zone, then the result * will be empty, but the operation itself remains successful (no error status set on return). * * <p>This implementation utilizes <a href="http://unicode.org/cldr/charts/supplemental/zone_tzid.html"> * Zone-Tzid mapping data</a>. The mapping data is updated time to time. To get the latest changes, * please read the ICU user guide section <a href="http://userguide.icu-project.org/datetime/timezone#TOC-Updating-the-Time-Zone-Data"> * Updating the Time Zone Data</a>. * * @param winid A Windows time zone ID. * @param region A null-terminated region code, or <code>NULL</code> if no regional preference. * @param id Receives a system time zone ID. When the input Windows time zone ID is unknown * or unmappable to a system time zone ID, then an empty string is set on return. * @param status Receives the status. * @return A reference to the result (<code>id</code>). * @see getWindowsID * * @stable ICU 52 */ static UnicodeString& U_EXPORT2 getIDForWindowsID(const UnicodeString& winid, const char* region, UnicodeString& id, UErrorCode& status); /** * Returns true if the two TimeZones are equal. (The TimeZone version only compares * IDs, but subclasses are expected to also compare the fields they add.) * * @param that The TimeZone object to be compared with. * @return True if the given TimeZone is equal to this TimeZone; false * otherwise. * @stable ICU 2.0 */ virtual UBool operator==(const TimeZone& that) const; /** * Returns true if the two TimeZones are NOT equal; that is, if operator==() returns * false. * * @param that The TimeZone object to be compared with. * @return True if the given TimeZone is not equal to this TimeZone; false * otherwise. * @stable ICU 2.0 */ UBool operator!=(const TimeZone& that) const {return !operator==(that);} /** * Returns the TimeZone's adjusted GMT offset (i.e., the number of milliseconds to add * to GMT to get local time in this time zone, taking daylight savings time into * account) as of a particular reference date. The reference date is used to determine * whether daylight savings time is in effect and needs to be figured into the offset * that is returned (in other words, what is the adjusted GMT offset in this time zone * at this particular date and time?). For the time zones produced by createTimeZone(), * the reference data is specified according to the Gregorian calendar, and the date * and time fields are local standard time. * * <p>Note: Don't call this method. Instead, call the getOffset(UDate...) overload, * which returns both the raw and the DST offset for a given time. This method * is retained only for backward compatibility. * * @param era The reference date's era * @param year The reference date's year * @param month The reference date's month (0-based; 0 is January) * @param day The reference date's day-in-month (1-based) * @param dayOfWeek The reference date's day-of-week (1-based; 1 is Sunday) * @param millis The reference date's milliseconds in day, local standard time * @param status Output param to filled in with a success or an error. * @return The offset in milliseconds to add to GMT to get local time. * @stable ICU 2.0 */ virtual int32_t getOffset(uint8_t era, int32_t year, int32_t month, int32_t day, uint8_t dayOfWeek, int32_t millis, UErrorCode& status) const = 0; /** * Gets the time zone offset, for current date, modified in case of * daylight savings. This is the offset to add *to* UTC to get local time. * * <p>Note: Don't call this method. Instead, call the getOffset(UDate...) overload, * which returns both the raw and the DST offset for a given time. This method * is retained only for backward compatibility. * * @param era the era of the given date. * @param year the year in the given date. * @param month the month in the given date. * Month is 0-based. e.g., 0 for January. * @param day the day-in-month of the given date. * @param dayOfWeek the day-of-week of the given date. * @param milliseconds the millis in day in <em>standard</em> local time. * @param monthLength the length of the given month in days. * @param status Output param to filled in with a success or an error. * @return the offset to add *to* GMT to get local time. * @stable ICU 2.0 */ virtual int32_t getOffset(uint8_t era, int32_t year, int32_t month, int32_t day, uint8_t dayOfWeek, int32_t milliseconds, int32_t monthLength, UErrorCode& status) const = 0; /** * Returns the time zone raw and GMT offset for the given moment * in time. Upon return, local-millis = GMT-millis + rawOffset + * dstOffset. All computations are performed in the proleptic * Gregorian calendar. The default implementation in the TimeZone * class delegates to the 8-argument getOffset(). * * @param date moment in time for which to return offsets, in * units of milliseconds from January 1, 1970 0:00 GMT, either GMT * time or local wall time, depending on `local'. * @param local if true, `date' is local wall time; otherwise it * is in GMT time. * @param rawOffset output parameter to receive the raw offset, that * is, the offset not including DST adjustments * @param dstOffset output parameter to receive the DST offset, * that is, the offset to be added to `rawOffset' to obtain the * total offset between local and GMT time. If DST is not in * effect, this value is zero; otherwise it is a positive value, * typically one hour. * @param ec input-output error code * * @stable ICU 2.8 */ virtual void getOffset(UDate date, UBool local, int32_t& rawOffset, int32_t& dstOffset, UErrorCode& ec) const; /** * Sets the TimeZone's raw GMT offset (i.e., the number of milliseconds to add * to GMT to get local time, before taking daylight savings time into account). * * @param offsetMillis The new raw GMT offset for this time zone. * @stable ICU 2.0 */ virtual void setRawOffset(int32_t offsetMillis) = 0; /** * Returns the TimeZone's raw GMT offset (i.e., the number of milliseconds to add * to GMT to get local time, before taking daylight savings time into account). * * @return The TimeZone's raw GMT offset. * @stable ICU 2.0 */ virtual int32_t getRawOffset(void) const = 0; /** * Fills in "ID" with the TimeZone's ID. * * @param ID Receives this TimeZone's ID. * @return A reference to 'ID' * @stable ICU 2.0 */ UnicodeString& getID(UnicodeString& ID) const; /** * Sets the TimeZone's ID to the specified value. This doesn't affect any other * fields (for example, if you say< * blockquote><pre> * . TimeZone* foo = TimeZone::createTimeZone("America/New_York"); * . foo.setID("America/Los_Angeles"); * </pre>\htmlonly</blockquote>\endhtmlonly * the time zone's GMT offset and daylight-savings rules don't change to those for * Los Angeles. They're still those for New York. Only the ID has changed.) * * @param ID The new time zone ID. * @stable ICU 2.0 */ void setID(const UnicodeString& ID); /** * Enum for use with getDisplayName * @stable ICU 2.4 */ enum EDisplayType { /** * Selector for short display name * @stable ICU 2.4 */ SHORT = 1, /** * Selector for long display name * @stable ICU 2.4 */ LONG, /** * Selector for short generic display name * @stable ICU 4.4 */ SHORT_GENERIC, /** * Selector for long generic display name * @stable ICU 4.4 */ LONG_GENERIC, /** * Selector for short display name derived * from time zone offset * @stable ICU 4.4 */ SHORT_GMT, /** * Selector for long display name derived * from time zone offset * @stable ICU 4.4 */ LONG_GMT, /** * Selector for short display name derived * from the time zone's fallback name * @stable ICU 4.4 */ SHORT_COMMONLY_USED, /** * Selector for long display name derived * from the time zone's fallback name * @stable ICU 4.4 */ GENERIC_LOCATION }; /** * Returns a name of this time zone suitable for presentation to the user * in the default locale. * This method returns the long name, not including daylight savings. * If the display name is not available for the locale, * then this method returns a string in the localized GMT offset format * such as <code>GMT[+-]HH:mm</code>. * @param result the human-readable name of this time zone in the default locale. * @return A reference to 'result'. * @stable ICU 2.0 */ UnicodeString& getDisplayName(UnicodeString& result) const; /** * Returns a name of this time zone suitable for presentation to the user * in the specified locale. * This method returns the long name, not including daylight savings. * If the display name is not available for the locale, * then this method returns a string in the localized GMT offset format * such as <code>GMT[+-]HH:mm</code>. * @param locale the locale in which to supply the display name. * @param result the human-readable name of this time zone in the given locale * or in the default locale if the given locale is not recognized. * @return A reference to 'result'. * @stable ICU 2.0 */ UnicodeString& getDisplayName(const Locale& locale, UnicodeString& result) const; /** * Returns a name of this time zone suitable for presentation to the user * in the default locale. * If the display name is not available for the locale, * then this method returns a string in the localized GMT offset format * such as <code>GMT[+-]HH:mm</code>. * @param daylight if true, return the daylight savings name. * @param style * @param result the human-readable name of this time zone in the default locale. * @return A reference to 'result'. * @stable ICU 2.0 */ UnicodeString& getDisplayName(UBool daylight, EDisplayType style, UnicodeString& result) const; /** * Returns a name of this time zone suitable for presentation to the user * in the specified locale. * If the display name is not available for the locale, * then this method returns a string in the localized GMT offset format * such as <code>GMT[+-]HH:mm</code>. * @param daylight if true, return the daylight savings name. * @param style * @param locale the locale in which to supply the display name. * @param result the human-readable name of this time zone in the given locale * or in the default locale if the given locale is not recognized. * @return A refence to 'result'. * @stable ICU 2.0 */ UnicodeString& getDisplayName(UBool daylight, EDisplayType style, const Locale& locale, UnicodeString& result) const; /** * Queries if this time zone uses daylight savings time. * @return true if this time zone uses daylight savings time, * false, otherwise. * <p><strong>Note:</strong>The default implementation of * ICU TimeZone uses the tz database, which supports historic * rule changes, for system time zones. With the implementation, * there are time zones that used daylight savings time in the * past, but no longer used currently. For example, Asia/Tokyo has * never used daylight savings time since 1951. Most clients would * expect that this method to return <code>FALSE</code> for such case. * The default implementation of this method returns <code>TRUE</code> * when the time zone uses daylight savings time in the current * (Gregorian) calendar year. * <p>In Java 7, <code>observesDaylightTime()</code> was added in * addition to <code>useDaylightTime()</code>. In Java, <code>useDaylightTime()</code> * only checks if daylight saving time is observed by the last known * rule. This specification might not be what most users would expect * if daylight saving time is currently observed, but not scheduled * in future. In this case, Java's <code>userDaylightTime()</code> returns * <code>false</code>. To resolve the issue, Java 7 added <code>observesDaylightTime()</code>, * which takes the current rule into account. The method <code>observesDaylightTime()</code> * was added in ICU4J for supporting API signature compatibility with JDK. * In general, ICU4C also provides JDK compatible methods, but the current * implementation <code>userDaylightTime()</code> serves the purpose * (takes the current rule into account), <code>observesDaylightTime()</code> * is not added in ICU4C. In addition to <code>useDaylightTime()</code>, ICU4C * <code>BasicTimeZone</code> class (Note that <code>TimeZone::createTimeZone(const UnicodeString &ID)</code> * always returns a <code>BasicTimeZone</code>) provides a series of methods allowing * historic and future time zone rule iteration, so you can check if daylight saving * time is observed or not within a given period. * * @stable ICU 2.0 */ virtual UBool useDaylightTime(void) const = 0; /** * Queries if the given date is in daylight savings time in * this time zone. * This method is wasteful since it creates a new GregorianCalendar and * deletes it each time it is called. This is a deprecated method * and provided only for Java compatibility. * * @param date the given UDate. * @param status Output param filled in with success/error code. * @return true if the given date is in daylight savings time, * false, otherwise. * @deprecated ICU 2.4. Use Calendar::inDaylightTime() instead. */ virtual UBool inDaylightTime(UDate date, UErrorCode& status) const = 0; /** * Returns true if this zone has the same rule and offset as another zone. * That is, if this zone differs only in ID, if at all. * @param other the <code>TimeZone</code> object to be compared with * @return true if the given zone is the same as this one, * with the possible exception of the ID * @stable ICU 2.0 */ virtual UBool hasSameRules(const TimeZone& other) const; /** * Clones TimeZone objects polymorphically. Clients are responsible for deleting * the TimeZone object cloned. * * @return A new copy of this TimeZone object. * @stable ICU 2.0 */ virtual TimeZone* clone(void) const = 0; /** * Return the class ID for this class. This is useful only for * comparing to a return value from getDynamicClassID(). * @return The class ID for all objects of this class. * @stable ICU 2.0 */ static UClassID U_EXPORT2 getStaticClassID(void); /** * Returns a unique class ID POLYMORPHICALLY. This method is to * implement a simple version of RTTI, since not all C++ compilers support genuine * RTTI. Polymorphic operator==() and clone() methods call this method. * <P> * Concrete subclasses of TimeZone must use the UOBJECT_DEFINE_RTTI_IMPLEMENTATION * macro from uobject.h in their implementation to provide correct RTTI information. * @return The class ID for this object. All objects of a given class have the * same class ID. Objects of other classes have different class IDs. * @stable ICU 2.0 */ virtual UClassID getDynamicClassID(void) const = 0; /** * Returns the amount of time to be added to local standard time * to get local wall clock time. * <p> * The default implementation always returns 3600000 milliseconds * (i.e., one hour) if this time zone observes Daylight Saving * Time. Otherwise, 0 (zero) is returned. * <p> * If an underlying TimeZone implementation subclass supports * historical Daylight Saving Time changes, this method returns * the known latest daylight saving value. * * @return the amount of saving time in milliseconds * @stable ICU 3.6 */ virtual int32_t getDSTSavings() const; /** * Gets the region code associated with the given * system time zone ID. The region code is either ISO 3166 * 2-letter country code or UN M.49 3-digit area code. * When the time zone is not associated with a specific location, * for example - "Etc/UTC", "EST5EDT", then this method returns * "001" (UN M.49 area code for World). * * @param id The system time zone ID. * @param region Output buffer for receiving the region code. * @param capacity The size of the output buffer. * @param status Receives the status. When the given time zone ID * is not a known system time zone ID, * U_ILLEGAL_ARGUMENT_ERROR is set. * @return The length of the output region code. * @stable ICU 4.8 */ static int32_t U_EXPORT2 getRegion(const UnicodeString& id, char *region, int32_t capacity, UErrorCode& status); protected: /** * Default constructor. ID is initialized to the empty string. * @stable ICU 2.0 */ TimeZone(); /** * Construct a TimeZone with a given ID. * @param id a system time zone ID * @stable ICU 2.0 */ TimeZone(const UnicodeString &id); /** * Copy constructor. * @param source the object to be copied. * @stable ICU 2.0 */ TimeZone(const TimeZone& source); /** * Default assignment operator. * @param right the object to be copied. * @stable ICU 2.0 */ TimeZone& operator=(const TimeZone& right); #ifndef U_HIDE_INTERNAL_API /** * Utility function. For internally loading rule data. * @param top Top resource bundle for tz data * @param ruleid ID of rule to load * @param oldbundle Old bundle to reuse or NULL * @param status Status parameter * @return either a new bundle or *oldbundle * @internal */ static UResourceBundle* loadRule(const UResourceBundle* top, const UnicodeString& ruleid, UResourceBundle* oldbundle, UErrorCode&status); #endif /* U_HIDE_INTERNAL_API */ private: friend class ZoneMeta; static TimeZone* createCustomTimeZone(const UnicodeString&); // Creates a time zone based on the string. /** * Finds the given ID in the Olson tzdata. If the given ID is found in the tzdata, * returns the pointer to the ID resource. This method is exposed through ZoneMeta class * for ICU internal implementation and useful for building hashtable using a time zone * ID as a key. * @param id zone id string * @return the pointer of the ID resource, or NULL. */ static const UChar* findID(const UnicodeString& id); /** * Resolve a link in Olson tzdata. When the given id is known and it's not a link, * the id itself is returned. When the given id is known and it is a link, then * dereferenced zone id is returned. When the given id is unknown, then it returns * NULL. * @param id zone id string * @return the dereferenced zone or NULL */ static const UChar* dereferOlsonLink(const UnicodeString& id); /** * Returns the region code associated with the given zone, * or NULL if the zone is not known. * @param id zone id string * @return the region associated with the given zone */ static const UChar* getRegion(const UnicodeString& id); public: #ifndef U_HIDE_INTERNAL_API /** * Returns the region code associated with the given zone, * or NULL if the zone is not known. * @param id zone id string * @param status Status parameter * @return the region associated with the given zone * @internal */ static const UChar* getRegion(const UnicodeString& id, UErrorCode& status); #endif /* U_HIDE_INTERNAL_API */ private: /** * Parses the given custom time zone identifier * @param id id A string of the form GMT[+-]hh:mm, GMT[+-]hhmm, or * GMT[+-]hh. * @param sign Receves parsed sign, 1 for positive, -1 for negative. * @param hour Receives parsed hour field * @param minute Receives parsed minute field * @param second Receives parsed second field * @return Returns TRUE when the given custom id is valid. */ static UBool parseCustomID(const UnicodeString& id, int32_t& sign, int32_t& hour, int32_t& minute, int32_t& second); /** * Parse a custom time zone identifier and return the normalized * custom time zone identifier for the given custom id string. * @param id a string of the form GMT[+-]hh:mm, GMT[+-]hhmm, or * GMT[+-]hh. * @param normalized Receives the normalized custom ID * @param status Receives the status. When the input ID string is invalid, * U_ILLEGAL_ARGUMENT_ERROR is set. * @return The normalized custom id string. */ static UnicodeString& getCustomID(const UnicodeString& id, UnicodeString& normalized, UErrorCode& status); /** * Returns the normalized custome time zone ID for the given offset fields. * @param hour offset hours * @param min offset minutes * @param sec offset seconds * @param negative sign of the offset, TRUE for negative offset. * @param id Receves the format result (normalized custom ID) * @return The reference to id */ static UnicodeString& formatCustomID(int32_t hour, int32_t min, int32_t sec, UBool negative, UnicodeString& id); UnicodeString fID; // this time zone's ID friend class TZEnumeration; }; // ------------------------------------- inline UnicodeString& TimeZone::getID(UnicodeString& ID) const { ID = fID; return ID; } // ------------------------------------- inline void TimeZone::setID(const UnicodeString& ID) { fID = ID; } U_NAMESPACE_END #endif /* #if !UCONFIG_NO_FORMATTING */ #endif //_TIMEZONE //eof