ICU 76.1: icu::SimpleTimeZone Class Reference

ICU 76.1 76.1

Public Types | Public Member Functions | Static Public Member Functions
icu::SimpleTimeZone Class Reference

`SimpleTimeZone` is a concrete subclass of `TimeZone` that represents a time zone for use with a Gregorian calendar. More...

`#include <simpletz.h>`

Inheritance diagram for icu::SimpleTimeZone:

## Public Types
enum | TimeMode { WALL_TIME = 0 , STANDARD_TIME , UTC_TIME }
| TimeMode is used, together with a millisecond offset after midnight, to specify a rule transition time. More...
Public Types inherited from icu::BasicTimeZone
enum | { kStandard = 0x01 , kDaylight = 0x03 , kFormer = 0x04 , kLatter = 0x0C }
| The time type option bit flags used by getOffsetFromLocal. More...
Public Types inherited from icu::TimeZone
enum | EDisplayType { SHORT = 1 , LONG , SHORT_GENERIC , LONG_GENERIC , SHORT_GMT , LONG_GMT , SHORT_COMMONLY_USED , GENERIC_LOCATION }
| Enum for use with getDisplayName. More...

## Public Member Functions
| SimpleTimeZone (const SimpleTimeZone &source)
| Copy constructor. More...
SimpleTimeZone & | operator= (const SimpleTimeZone &right)
| Default assignment operator. More...
virtual | ~SimpleTimeZone ()
| Destructor. More...
virtual bool | operator== (const TimeZone &that) const override
| Returns true if the two TimeZone objects are equal; that is, they have the same ID, raw GMT offset, and DST rules. More...
| SimpleTimeZone (int32_t rawOffsetGMT, const UnicodeString &ID)
| Constructs a SimpleTimeZone with the given raw GMT offset and time zone ID, and which doesn't observe daylight savings time. More...
| SimpleTimeZone (int32_t rawOffsetGMT, const UnicodeString &ID, int8_t savingsStartMonth, int8_t savingsStartDayOfWeekInMonth, int8_t savingsStartDayOfWeek, int32_t savingsStartTime, int8_t savingsEndMonth, int8_t savingsEndDayOfWeekInMonth, int8_t savingsEndDayOfWeek, int32_t savingsEndTime, UErrorCode &status)
| Construct a SimpleTimeZone with the given raw GMT offset, time zone ID, and times to start and end daylight savings time. More...
| SimpleTimeZone (int32_t rawOffsetGMT, const UnicodeString &ID, int8_t savingsStartMonth, int8_t savingsStartDayOfWeekInMonth, int8_t savingsStartDayOfWeek, int32_t savingsStartTime, int8_t savingsEndMonth, int8_t savingsEndDayOfWeekInMonth, int8_t savingsEndDayOfWeek, int32_t savingsEndTime, int32_t savingsDST, UErrorCode &status)
| Construct a SimpleTimeZone with the given raw GMT offset, time zone ID, and times to start and end daylight savings time. More...
| SimpleTimeZone (int32_t rawOffsetGMT, const UnicodeString &ID, int8_t savingsStartMonth, int8_t savingsStartDayOfWeekInMonth, int8_t savingsStartDayOfWeek, int32_t savingsStartTime, TimeMode savingsStartTimeMode, int8_t savingsEndMonth, int8_t savingsEndDayOfWeekInMonth, int8_t savingsEndDayOfWeek, int32_t savingsEndTime, TimeMode savingsEndTimeMode, int32_t savingsDST, UErrorCode &status)
| Construct a SimpleTimeZone with the given raw GMT offset, time zone ID, and times to start and end daylight savings time. More...
void | setStartYear (int32_t year)
| Sets the daylight savings starting year, that is, the year this time zone began observing its specified daylight savings time rules. More...
void | setStartRule (int32_t month, int32_t dayOfWeekInMonth, int32_t dayOfWeek, int32_t time, UErrorCode &status)
| Sets the daylight savings starting rule. More...
void | setStartRule (int32_t month, int32_t dayOfWeekInMonth, int32_t dayOfWeek, int32_t time, TimeMode mode, UErrorCode &status)
| Sets the daylight savings starting rule. More...
void | setStartRule (int32_t month, int32_t dayOfMonth, int32_t time, UErrorCode &status)
| Sets the DST start rule to a fixed date within a month. More...
void | setStartRule (int32_t month, int32_t dayOfMonth, int32_t time, TimeMode mode, UErrorCode &status)
| Sets the DST start rule to a fixed date within a month. More...
void | setStartRule (int32_t month, int32_t dayOfMonth, int32_t dayOfWeek, int32_t time, UBool after, UErrorCode &status)
| Sets the DST start rule to a weekday before or after a give date within a month, e.g., the first Monday on or after the 8th. More...
void | setStartRule (int32_t month, int32_t dayOfMonth, int32_t dayOfWeek, int32_t time, TimeMode mode, UBool after, UErrorCode &status)
| Sets the DST start rule to a weekday before or after a give date within a month, e.g., the first Monday on or after the 8th. More...
void | setEndRule (int32_t month, int32_t dayOfWeekInMonth, int32_t dayOfWeek, int32_t time, UErrorCode &status)
| Sets the daylight savings ending rule. More...
void | setEndRule (int32_t month, int32_t dayOfWeekInMonth, int32_t dayOfWeek, int32_t time, TimeMode mode, UErrorCode &status)
| Sets the daylight savings ending rule. More...
void | setEndRule (int32_t month, int32_t dayOfMonth, int32_t time, UErrorCode &status)
| Sets the DST end rule to a fixed date within a month. More...
void | setEndRule (int32_t month, int32_t dayOfMonth, int32_t time, TimeMode mode, UErrorCode &status)
| Sets the DST end rule to a fixed date within a month. More...
void | setEndRule (int32_t month, int32_t dayOfMonth, int32_t dayOfWeek, int32_t time, UBool after, UErrorCode &status)
| Sets the DST end rule to a weekday before or after a give date within a month, e.g., the first Monday on or after the 8th. More...
void | setEndRule (int32_t month, int32_t dayOfMonth, int32_t dayOfWeek, int32_t time, TimeMode mode, UBool after, UErrorCode &status)
| Sets the DST end rule to a weekday before or after a give date within a month, e.g., the first Monday on or after the 8th. More...
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 override
| 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. More...
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 override
| Gets the time zone offset, for current date, modified in case of daylight savings. More...
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, int32_t prevMonthLength, UErrorCode &status) const
| Gets the time zone offset, for current date, modified in case of daylight savings. More...
virtual void | getOffset (UDate date, UBool local, int32_t &rawOffset, int32_t &dstOffset, UErrorCode &ec) const override
| Redeclared TimeZone method. More...
virtual void | getOffsetFromLocal (UDate date, UTimeZoneLocalOption nonExistingTimeOpt, UTimeZoneLocalOption duplicatedTimeOpt, int32_t &rawOffset, int32_t &dstOffset, UErrorCode &status) const override
| Get time zone offsets from local wall time. More...
virtual int32_t | getRawOffset () const override
| 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). More...
virtual void | setRawOffset (int32_t offsetMillis) override
| 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). More...
void | setDSTSavings (int32_t millisSavedDuringDST, UErrorCode &status)
| Sets the amount of time in ms that the clock is advanced during DST. More...
virtual int32_t | getDSTSavings () const override
| Returns the amount of time in ms that the clock is advanced during DST. More...
virtual UBool | useDaylightTime () const override
| Queries if this TimeZone uses Daylight Savings Time. More...
virtual UBool | inDaylightTime (UDate date, UErrorCode &status) const override
| Returns true if the given date is within the period when daylight savings time is in effect; false otherwise. More...
UBool | hasSameRules (const TimeZone &other) const override
| Return true if this zone has the same rules and offset as another zone. More...
virtual SimpleTimeZone * | clone () const override
| Clones TimeZone objects polymorphically. More...
virtual UBool | getNextTransition (UDate base, UBool inclusive, TimeZoneTransition &result) const override
| Gets the first time zone transition after the base time. More...
virtual UBool | getPreviousTransition (UDate base, UBool inclusive, TimeZoneTransition &result) const override
| Gets the most recent time zone transition before the base time. More...
virtual int32_t | countTransitionRules (UErrorCode &status) const override
| Returns the number of `TimeZoneRule`s which represents time transitions, for this time zone, that is, all `TimeZoneRule`s for this time zone except `InitialTimeZoneRule`. More...
virtual void | getTimeZoneRules (const InitialTimeZoneRule *&initial, const TimeZoneRule *trsrules[], int32_t &trscount, UErrorCode &status) const override
| Gets the `InitialTimeZoneRule` and the set of `TimeZoneRule` which represent time transitions for this time zone. More...
virtual UClassID | getDynamicClassID () const override
| Override TimeZone Returns a unique class ID POLYMORPHICALLY. More...
Public Member Functions inherited from icu::BasicTimeZone
virtual | ~BasicTimeZone ()
| Destructor. More...
virtual UBool | hasEquivalentTransitions (const BasicTimeZone &tz, UDate start, UDate end, UBool ignoreDstAmount, UErrorCode &ec) const
| Checks if the time zone has equivalent transitions in the time range. More...
virtual void | getSimpleRulesNear (UDate date, InitialTimeZoneRule *&initial, AnnualTimeZoneRule *&std, AnnualTimeZoneRule *&dst, UErrorCode &status) const
| Gets the set of time zone rules valid at the specified time. More...
void | getOffsetFromLocal (UDate date, int32_t nonExistingTimeOpt, int32_t duplicatedTimeOpt, int32_t &rawOffset, int32_t &dstOffset, UErrorCode &status) const
| Get time zone offsets from local wall time. More...
Public Member Functions inherited from icu::TimeZone
virtual | ~TimeZone ()
bool | operator!= (const TimeZone &that) const
| Returns true if the two TimeZones are NOT equal; that is, if operator==() returns false. More...
UnicodeString & | getID (UnicodeString &ID) const
| Fills in "ID" with the TimeZone's ID. More...
void | setID (const UnicodeString &ID)
| Sets the TimeZone's ID to the specified value. More...
UnicodeString & | getDisplayName (UnicodeString &result) const
| Returns a name of this time zone suitable for presentation to the user in the default locale. More...
UnicodeString & | getDisplayName (const Locale &locale, UnicodeString &result) const
| Returns a name of this time zone suitable for presentation to the user in the specified locale. More...
UnicodeString & | getDisplayName (UBool inDaylight, EDisplayType style, UnicodeString &result) const
| Returns a name of this time zone suitable for presentation to the user in the default locale. More...
UnicodeString & | getDisplayName (UBool inDaylight, EDisplayType style, const Locale &locale, UnicodeString &result) const
| Returns a name of this time zone suitable for presentation to the user in the specified locale. More...
Public Member Functions inherited from icu::UObject
virtual | ~UObject ()
| Destructor. More...

## Static Public Member Functions
static UClassID | getStaticClassID ()
| Return the class ID for this class. More...
Static Public Member Functions inherited from icu::TimeZone
static const TimeZone & | getUnknown ()
| Returns the "unknown" time zone. More...
static const TimeZone * | getGMT ()
| The GMT (=UTC) time zone has a raw offset of zero and does not use daylight savings time. More...
static TimeZone * | createTimeZone (const UnicodeString &ID)
| Creates a `TimeZone` for the given ID. More...
static StringEnumeration * | createTimeZoneIDEnumeration (USystemTimeZoneType zoneType, const char *region, const int32_t *rawOffset, UErrorCode &ec)
| Returns an enumeration over system time zone IDs with the given filter conditions. More...
static StringEnumeration * | createEnumeration ()
| Returns an enumeration over all recognized time zone IDs. More...
static StringEnumeration * | createEnumeration (UErrorCode &status)
| Returns an enumeration over all recognized time zone IDs. More...
static StringEnumeration * | createEnumeration (int32_t rawOffset)
| Returns an enumeration over time zone IDs with a given raw offset from GMT. More...
static StringEnumeration * | createEnumerationForRawOffset (int32_t rawOffset, UErrorCode &status)
| Returns an enumeration over time zone IDs with a given raw offset from GMT. More...
static StringEnumeration * | createEnumeration (const char *region)
| Returns an enumeration over time zone IDs associated with the given region. More...
static StringEnumeration * | createEnumerationForRegion (const char *region, UErrorCode &status)
| Returns an enumeration over time zone IDs associated with the given region. More...
static int32_t | countEquivalentIDs (const UnicodeString &id)
| Returns the number of IDs in the equivalency group that includes the given ID. More...
static const UnicodeString | getEquivalentID (const UnicodeString &id, int32_t index)
| Returns an ID in the equivalency group that includes the given ID. More...
static TimeZone * | detectHostTimeZone ()
| Creates an instance of TimeZone detected from the current host system configuration. More...
static TimeZone * | createDefault ()
| Creates a new copy of the default TimeZone for this host. More...
static TimeZone * | forLocaleOrDefault (const Locale &locale)
| If the locale contains the timezone keyword, creates a copy of that TimeZone. More...
static void | adoptDefault (TimeZone *zone)
| Sets the default time zone (i.e., what's returned by createDefault()) to be the specified time zone. More...
static void | setDefault (const TimeZone &zone)
| Same as adoptDefault(), except that the TimeZone object passed in is NOT adopted; the caller remains responsible for deleting it. More...
static const char * | getTZDataVersion (UErrorCode &status)
| Returns the timezone data version currently used by ICU. More...
static UnicodeString & | getCanonicalID (const UnicodeString &id, UnicodeString &canonicalID, UErrorCode &status)
| Returns the canonical system timezone ID or the normalized custom time zone ID for the given time zone ID. More...
static UnicodeString & | getCanonicalID (const UnicodeString &id, UnicodeString &canonicalID, UBool &isSystemID, UErrorCode &status)
| Returns the canonical system time zone ID or the normalized custom time zone ID for the given time zone ID. More...
static UnicodeString & | getIanaID (const UnicodeString &id, UnicodeString &ianaID, UErrorCode &status)
| Returns the preferred time zone ID in the IANA time zone database for the given time zone ID. More...
static UnicodeString & | getWindowsID (const UnicodeString &id, UnicodeString &winid, UErrorCode &status)
| Converts a system time zone ID to an equivalent Windows time zone ID. More...
static UnicodeString & | getIDForWindowsID (const UnicodeString &winid, const char *region, UnicodeString &id, UErrorCode &status)
| Converts a Windows time zone ID to an equivalent system time zone ID for a region. More...
static UClassID | getStaticClassID ()
| Return the class ID for this class. More...
static int32_t | getRegion (const UnicodeString &id, char *region, int32_t capacity, UErrorCode &status)
| Gets the region code associated with the given system time zone ID. More...
static const char16_t * | getRegion (const UnicodeString &id, UErrorCode &status)
| Returns the region code associated with the given zone, or nullptr if the zone is not known. More...

## Additional Inherited Members
Protected Member Functions inherited from icu::BasicTimeZone
| BasicTimeZone ()
| Default constructor. More...
| BasicTimeZone (const UnicodeString &id)
| Construct a timezone with a given ID. More...
| BasicTimeZone (const BasicTimeZone &source)
| Copy constructor. More...
BasicTimeZone & | operator= (const BasicTimeZone &)=default
| Copy assignment. More...
void | getTimeZoneRulesAfter (UDate start, InitialTimeZoneRule *&initial, UVector *&transitionRules, UErrorCode &status) const
| Gets the set of TimeZoneRule instances applicable to the specified time and after. More...
Protected Member Functions inherited from icu::TimeZone
| TimeZone ()
| Default constructor. More...
| TimeZone (const UnicodeString &id)
| Construct a TimeZone with a given ID. More...
| TimeZone (const TimeZone &source)
| Copy constructor. More...
TimeZone & | operator= (const TimeZone &right)
| Default assignment operator. More...
Static Protected Member Functions inherited from icu::TimeZone
static UResourceBundle * | loadRule (const UResourceBundle *top, const UnicodeString &ruleid, UResourceBundle *oldbundle, UErrorCode &status)
| Utility function. More...
Static Protected Attributes inherited from icu::BasicTimeZone
static constexpr int32_t | kStdDstMask = kDaylight
| A time type option bit mask used by getOffsetFromLocal. More...
static constexpr int32_t | kFormerLatterMask = kLatter
| A time type option bit mask used by getOffsetFromLocal. More...

## Detailed Description

`SimpleTimeZone` is a concrete subclass of `TimeZone` that represents a time zone for use with a Gregorian calendar.

This class does not handle historical changes.

When specifying daylight-savings-time begin and end dates, use a negative value for `dayOfWeekInMonth` to indicate that `SimpleTimeZone` should count from the end of the month backwards. For example, if Daylight Savings Time starts or ends at the last Sunday a month, use `dayOfWeekInMonth = -1` along with `dayOfWeek = UCAL_SUNDAY` to specify the rule.

See also
  Calendar
  GregorianCalendar
  TimeZone

Author
  D. Goldsmith, Mark Davis, Chen-Lieh Huang, Alan Liu

Definition at line 65 of file simpletz.h.

## Member Enumeration Documentation

## ◆ TimeMode

enum icu::SimpleTimeZone::TimeMode

TimeMode is used, together with a millisecond offset after midnight, to specify a rule transition time.

Most rules transition at a local wall time, that is, according to the current time in effect, either standard, or DST. However, some rules transition at local standard time, and some at a specific UTC time. Although it might seem that all times could be converted to wall time, thus eliminating the need for this parameter, this is not the case.

Stable:
  ICU 2.0

Definition at line 79 of file simpletz.h.

## Constructor & Destructor Documentation

## ◆ SimpleTimeZone() [1/5]

icu::SimpleTimeZone::SimpleTimeZone | ( | const SimpleTimeZone & | source | ) |

Copy constructor.

Parameters

  source | the object to be copied.

Stable:
  ICU 2.0

## ◆ ~SimpleTimeZone()

virtual icu::SimpleTimeZone::~SimpleTimeZone | ( |  | ) |
| virtual

Destructor.

Stable:
  ICU 2.0

## ◆ SimpleTimeZone() [2/5]

icu::SimpleTimeZone::SimpleTimeZone | ( | int32_t | rawOffsetGMT,
|  | const UnicodeString & | ID
| ) |  |

Constructs a SimpleTimeZone with the given raw GMT offset and time zone ID, and which doesn't observe daylight savings time.

Normally you should use TimeZone::createInstance() to create a TimeZone instead of creating a SimpleTimeZone directly with this constructor.

Parameters

  rawOffsetGMT | The given base time zone offset to GMT.
  ID | The timezone ID which is obtained from TimeZone.getAvailableIDs.

Stable:
  ICU 2.0

## ◆ SimpleTimeZone() [3/5]

icu::SimpleTimeZone::SimpleTimeZone | ( | int32_t | rawOffsetGMT,
|  | const UnicodeString & | ID,
|  | int8_t | savingsStartMonth,
|  | int8_t | savingsStartDayOfWeekInMonth,
|  | int8_t | savingsStartDayOfWeek,
|  | int32_t | savingsStartTime,
|  | int8_t | savingsEndMonth,
|  | int8_t | savingsEndDayOfWeekInMonth,
|  | int8_t | savingsEndDayOfWeek,
|  | int32_t | savingsEndTime,
|  | UErrorCode & | status
| ) |  |

Construct a SimpleTimeZone with the given raw GMT offset, time zone ID, and times to start and end daylight savings time.

To create a TimeZone that doesn't observe daylight savings time, don't use this constructor; use SimpleTimeZone(rawOffset, ID) instead. Normally, you should use TimeZone.createInstance() to create a TimeZone instead of creating a SimpleTimeZone directly with this constructor.

Various types of daylight-savings time rules can be specified by using different values for startDay and startDayOfWeek and endDay and endDayOfWeek. For a complete explanation of how these parameters work, see the documentation for setStartRule().

Parameters

  rawOffsetGMT | The new SimpleTimeZone's raw GMT offset
  ID | The new SimpleTimeZone's time zone ID.
  savingsStartMonth | The daylight savings starting month. Month is 0-based. eg, 0 for January.
  savingsStartDayOfWeekInMonth | The daylight savings starting day-of-week-in-month. See setStartRule() for a complete explanation.
  savingsStartDayOfWeek | The daylight savings starting day-of-week. See setStartRule() for a complete explanation.
  savingsStartTime | The daylight savings starting time, expressed as the number of milliseconds after midnight.
  savingsEndMonth | The daylight savings ending month. Month is 0-based. eg, 0 for January.
  savingsEndDayOfWeekInMonth | The daylight savings ending day-of-week-in-month. See setStartRule() for a complete explanation.
  savingsEndDayOfWeek | The daylight savings ending day-of-week. See setStartRule() for a complete explanation.
  savingsEndTime | The daylight savings ending time, expressed as the number of milliseconds after midnight.
  status | An UErrorCode to receive the status.

Stable:
  ICU 2.0

## ◆ SimpleTimeZone() [4/5]

icu::SimpleTimeZone::SimpleTimeZone | ( | int32_t | rawOffsetGMT,
|  | const UnicodeString & | ID,
|  | int8_t | savingsStartMonth,
|  | int8_t | savingsStartDayOfWeekInMonth,
|  | int8_t | savingsStartDayOfWeek,
|  | int32_t | savingsStartTime,
|  | int8_t | savingsEndMonth,
|  | int8_t | savingsEndDayOfWeekInMonth,
|  | int8_t | savingsEndDayOfWeek,
|  | int32_t | savingsEndTime,
|  | int32_t | savingsDST,
|  | UErrorCode & | status
| ) |  |

Construct a SimpleTimeZone with the given raw GMT offset, time zone ID, and times to start and end daylight savings time.

To create a TimeZone that doesn't observe daylight savings time, don't use this constructor; use SimpleTimeZone(rawOffset, ID) instead. Normally, you should use TimeZone.createInstance() to create a TimeZone instead of creating a SimpleTimeZone directly with this constructor.

Various types of daylight-savings time rules can be specified by using different values for startDay and startDayOfWeek and endDay and endDayOfWeek. For a complete explanation of how these parameters work, see the documentation for setStartRule().

Parameters

  rawOffsetGMT | The new SimpleTimeZone's raw GMT offset
  ID | The new SimpleTimeZone's time zone ID.
  savingsStartMonth | The daylight savings starting month. Month is 0-based. eg, 0 for January.
  savingsStartDayOfWeekInMonth | The daylight savings starting day-of-week-in-month. See setStartRule() for a complete explanation.
  savingsStartDayOfWeek | The daylight savings starting day-of-week. See setStartRule() for a complete explanation.
  savingsStartTime | The daylight savings starting time, expressed as the number of milliseconds after midnight.
  savingsEndMonth | The daylight savings ending month. Month is 0-based. eg, 0 for January.
  savingsEndDayOfWeekInMonth | The daylight savings ending day-of-week-in-month. See setStartRule() for a complete explanation.
  savingsEndDayOfWeek | The daylight savings ending day-of-week. See setStartRule() for a complete explanation.
  savingsEndTime | The daylight savings ending time, expressed as the number of milliseconds after midnight.
  savingsDST | The number of milliseconds added to standard time to get DST time. Default is one hour.
  status | An UErrorCode to receive the status.

Stable:
  ICU 2.0

## ◆ SimpleTimeZone() [5/5]

icu::SimpleTimeZone::SimpleTimeZone | ( | int32_t | rawOffsetGMT,
|  | const UnicodeString & | ID,
|  | int8_t | savingsStartMonth,
|  | int8_t | savingsStartDayOfWeekInMonth,
|  | int8_t | savingsStartDayOfWeek,
|  | int32_t | savingsStartTime,
|  | TimeMode | savingsStartTimeMode,
|  | int8_t | savingsEndMonth,
|  | int8_t | savingsEndDayOfWeekInMonth,
|  | int8_t | savingsEndDayOfWeek,
|  | int32_t | savingsEndTime,
|  | TimeMode | savingsEndTimeMode,
|  | int32_t | savingsDST,
|  | UErrorCode & | status
| ) |  |

Construct a SimpleTimeZone with the given raw GMT offset, time zone ID, and times to start and end daylight savings time.

To create a TimeZone that doesn't observe daylight savings time, don't use this constructor; use SimpleTimeZone(rawOffset, ID) instead. Normally, you should use TimeZone.createInstance() to create a TimeZone instead of creating a SimpleTimeZone directly with this constructor.

Various types of daylight-savings time rules can be specified by using different values for startDay and startDayOfWeek and endDay and endDayOfWeek. For a complete explanation of how these parameters work, see the documentation for setStartRule().

Parameters

  rawOffsetGMT | The new SimpleTimeZone's raw GMT offset
  ID | The new SimpleTimeZone's time zone ID.
  savingsStartMonth | The daylight savings starting month. Month is 0-based. eg, 0 for January.
  savingsStartDayOfWeekInMonth | The daylight savings starting day-of-week-in-month. See setStartRule() for a complete explanation.
  savingsStartDayOfWeek | The daylight savings starting day-of-week. See setStartRule() for a complete explanation.
  savingsStartTime | The daylight savings starting time, expressed as the number of milliseconds after midnight.
  savingsStartTimeMode | Whether the start time is local wall time, local standard time, or UTC time. Default is local wall time.
  savingsEndMonth | The daylight savings ending month. Month is 0-based. eg, 0 for January.
  savingsEndDayOfWeekInMonth | The daylight savings ending day-of-week-in-month. See setStartRule() for a complete explanation.
  savingsEndDayOfWeek | The daylight savings ending day-of-week. See setStartRule() for a complete explanation.
  savingsEndTime | The daylight savings ending time, expressed as the number of milliseconds after midnight.
  savingsEndTimeMode | Whether the end time is local wall time, local standard time, or UTC time. Default is local wall time.
  savingsDST | The number of milliseconds added to standard time to get DST time. Default is one hour.
  status | An UErrorCode to receive the status.

Stable:
  ICU 2.0

## Member Function Documentation

## ◆ clone()

virtual SimpleTimeZone* icu::SimpleTimeZone::clone | ( |  | ) | const
| overridevirtual

Clones TimeZone objects polymorphically.

Clients are responsible for deleting the TimeZone object cloned.

Returns
  A new copy of this TimeZone object.

Stable:
  ICU 2.0

Implements icu::BasicTimeZone.

## ◆ countTransitionRules()

virtual int32_t icu::SimpleTimeZone::countTransitionRules | ( | UErrorCode & | status | ) | const
| overridevirtual

Returns the number of `TimeZoneRule`s which represents time transitions, for this time zone, that is, all `TimeZoneRule`s for this time zone except `InitialTimeZoneRule`.

The return value range is 0 or any positive value.

Parameters

  status | Receives error status code.

Returns
  The number of `TimeZoneRule`s representing time transitions.

Stable:
  ICU 3.8

Implements icu::BasicTimeZone.

## ◆ getDSTSavings()

virtual int32_t icu::SimpleTimeZone::getDSTSavings | ( |  | ) | const
| overridevirtual

Returns the amount of time in ms that the clock is advanced during DST.

Returns
  the number of milliseconds the time is advanced with respect to standard time when the daylight savings rules are in effect. Typically one hour (+3600000). The amount could be negative, but not 0.

Stable:
  ICU 2.0

Reimplemented from icu::TimeZone.

## ◆ getDynamicClassID()

virtual UClassID icu::SimpleTimeZone::getDynamicClassID | ( |  | ) | const
| overridevirtual

Override TimeZone Returns a unique class ID POLYMORPHICALLY.

Pure virtual override. 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.

Returns
  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

Implements icu::TimeZone.

## ◆ getNextTransition()

virtual UBool icu::SimpleTimeZone::getNextTransition | ( | UDate | base,
|  | UBool | inclusive,
|  | TimeZoneTransition & | result
| ) |  | const
| overridevirtual

Gets the first time zone transition after the base time.

Parameters

  base | The base time.
  inclusive | Whether the base time is inclusive or not.
  result | Receives the first transition after the base time.

Returns
  true if the transition is found.

Stable:
  ICU 3.8

Implements icu::BasicTimeZone.

## ◆ getOffset() [1/4]

void icu::SimpleTimeZone::getOffset | ( | UDate | date,
|  | UBool | local,
|  | int32_t & | rawOffset,
|  | int32_t & | dstOffset,
|  | UErrorCode & | ec
| ) |  | const
| inlineoverridevirtual

Redeclared TimeZone method.

This implementation simply calls the base class method, which otherwise would be hidden.

Stable:
  ICU 2.8

Reimplemented from icu::TimeZone.

Definition at line 929 of file simpletz.h.

## ◆ getOffset() [2/4]

virtual int32_t icu::SimpleTimeZone::getOffset | ( | uint8_t | era,
|  | int32_t | year,
|  | int32_t | month,
|  | int32_t | day,
|  | uint8_t | dayOfWeek,
|  | int32_t | millis,
|  | UErrorCode & | status
| ) |  | const
| overridevirtual

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 in GMT, NOT local time.

Parameters

  era | The reference date's era
  year | The reference date's year
  month | The reference date's month (0-based; 0 is January)
  day | The reference date's day-in-month (1-based)
  dayOfWeek | The reference date's day-of-week (1-based; 1 is Sunday)
  millis | The reference date's milliseconds in day, UTT (NOT local time).
  status | An UErrorCode to receive the status.

Returns
  The offset in milliseconds to add to GMT to get local time.

Stable:
  ICU 2.0

Implements icu::TimeZone.

## ◆ getOffset() [3/4]

virtual int32_t icu::SimpleTimeZone::getOffset | ( | uint8_t | era,
|  | int32_t | year,
|  | int32_t | month,
|  | int32_t | day,
|  | uint8_t | dayOfWeek,
|  | int32_t | milliseconds,
|  | int32_t | monthLength,
|  | int32_t | prevMonthLength,
|  | UErrorCode & | status
| ) |  | const
| virtual

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.

Parameters

  era | the era of the given date.
  year | the year in the given date.
  month | the month in the given date. Month is 0-based. e.g., 0 for January.
  day | the day-in-month of the given date.
  dayOfWeek | the day-of-week of the given date.
  milliseconds | the millis in day in standard local time.
  monthLength | the length of the given month in days.
  prevMonthLength | length of the previous month in days.
  status | An UErrorCode to receive the status.

Returns
  the offset to add to GMT to get local time.

Stable:
  ICU 2.0

## ◆ getOffset() [4/4]

virtual int32_t icu::SimpleTimeZone::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
| overridevirtual

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.

Parameters

  era | the era of the given date.
  year | the year in the given date.
  month | the month in the given date. Month is 0-based. e.g., 0 for January.
  day | the day-in-month of the given date.
  dayOfWeek | the day-of-week of the given date.
  milliseconds | the millis in day in standard local time.
  monthLength | the length of the given month in days.
  status | An UErrorCode to receive the status.

Returns
  the offset to add to GMT to get local time.

Stable:
  ICU 2.0

Implements icu::TimeZone.

## ◆ getOffsetFromLocal()

virtual void icu::SimpleTimeZone::getOffsetFromLocal | ( | UDate | date,
|  | UTimeZoneLocalOption | nonExistingTimeOpt,
|  | UTimeZoneLocalOption | duplicatedTimeOpt,
|  | int32_t & | rawOffset,
|  | int32_t & | dstOffset,
|  | UErrorCode & | status
| ) |  | const
| overridevirtual

Get time zone offsets from local wall time.

Stable:
  ICU 69

Reimplemented from icu::BasicTimeZone.

## ◆ getPreviousTransition()

virtual UBool icu::SimpleTimeZone::getPreviousTransition | ( | UDate | base,
|  | UBool | inclusive,
|  | TimeZoneTransition & | result
| ) |  | const
| overridevirtual

Gets the most recent time zone transition before the base time.

Parameters

  base | The base time.
  inclusive | Whether the base time is inclusive or not.
  result | Receives the most recent transition before the base time.

Returns
  true if the transition is found.

Stable:
  ICU 3.8

Implements icu::BasicTimeZone.

## ◆ getRawOffset()

virtual int32_t icu::SimpleTimeZone::getRawOffset | ( |  | ) | const
| overridevirtual

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).

Returns
  The TimeZone's raw GMT offset.

Stable:
  ICU 2.0

Implements icu::TimeZone.

## ◆ getStaticClassID()

static UClassID icu::SimpleTimeZone::getStaticClassID | ( |  | ) |
| static

Return the class ID for this class.

This is useful only for comparing to a return value from getDynamicClassID(). For example:

    .   Base* polymorphic_pointer = createPolymorphicObject();
    .   if (polymorphic_pointer->getDynamicClassID() ==
    .       Derived::getStaticClassID()) ...

Returns
  The class ID for all objects of this class.

Stable:
  ICU 2.0

## ◆ getTimeZoneRules()

virtual void icu::SimpleTimeZone::getTimeZoneRules | ( | const InitialTimeZoneRule *& | initial,
|  | const TimeZoneRule * | trsrules[],
|  | int32_t & | trscount,
|  | UErrorCode & | status
| ) |  | const
| overridevirtual

Gets the `InitialTimeZoneRule` and the set of `TimeZoneRule` which represent time transitions for this time zone.

On successful return, the argument initial points to non-nullptr `InitialTimeZoneRule` and the array trsrules is filled with 0 or multiple `TimeZoneRule` instances up to the size specified by trscount. The results are referencing the rule instance held by this time zone instance. Therefore, after this time zone is destructed, they are no longer available.

Parameters

  initial | Receives the initial timezone rule
  trsrules | Receives the timezone transition rules
  trscount | On input, specify the size of the array 'transitions' receiving the timezone transition rules. On output, actual number of rules filled in the array will be set.
  status | Receives error status code.

Stable:
  ICU 3.8

Implements icu::BasicTimeZone.

## ◆ hasSameRules()

UBool icu::SimpleTimeZone::hasSameRules | ( | const TimeZone & | other | ) | const
| overridevirtual

Return true if this zone has the same rules and offset as another zone.

Parameters

  other | the TimeZone object to be compared with

Returns
  true if the given zone has the same rules and offset as this one

Stable:
  ICU 2.0

Reimplemented from icu::TimeZone.

## ◆ inDaylightTime()

virtual UBool icu::SimpleTimeZone::inDaylightTime | ( | UDate | date,
|  | UErrorCode & | status
| ) |  | const
| overridevirtual

Returns true if the given date is within the period when daylight savings time is in effect; false otherwise.

If the TimeZone doesn't observe daylight savings time, this functions always returns false. 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.

Parameters

  date | The date to test.
  status | An UErrorCode to receive the status.

Returns
  true if the given date is in Daylight Savings Time; false otherwise.

Deprecated:
  ICU 2.4. Use Calendar::inDaylightTime() instead.

Implements icu::TimeZone.

## ◆ operator=()

SimpleTimeZone& icu::SimpleTimeZone::operator= | ( | const SimpleTimeZone & | right | ) |

Default assignment operator.

Parameters

  right | the object to be copied.

Stable:
  ICU 2.0

## ◆ operator==()

virtual bool icu::SimpleTimeZone::operator== | ( | const TimeZone & | that | ) | const
| overridevirtual

Returns true if the two TimeZone objects are equal; that is, they have the same ID, raw GMT offset, and DST rules.

Parameters

  that | The SimpleTimeZone object to be compared with.

Returns
  true if the given time zone is equal to this time zone; false otherwise.

Stable:
  ICU 2.0

Reimplemented from icu::TimeZone.

## ◆ setDSTSavings()

void icu::SimpleTimeZone::setDSTSavings | ( | int32_t | millisSavedDuringDST,
|  | UErrorCode & | status
| ) |  |

Sets the amount of time in ms that the clock is advanced during DST.

Parameters

  millisSavedDuringDST | the number of milliseconds the time is advanced with respect to standard time when the daylight savings rules are in effect. Typically one hour (+3600000). The amount could be negative, but not 0.
  status | An UErrorCode to receive the status.

Stable:
  ICU 2.0

## ◆ setEndRule() [1/6]

void icu::SimpleTimeZone::setEndRule | ( | int32_t | month,
|  | int32_t | dayOfMonth,
|  | int32_t | dayOfWeek,
|  | int32_t | time,
|  | TimeMode | mode,
|  | UBool | after,
|  | UErrorCode & | status
| ) |  |

Sets the DST end rule to a weekday before or after a give date within a month, e.g., the first Monday on or after the 8th.

Parameters

  month | The month in which this rule occurs (0-based).
  dayOfMonth | A date within that month (1-based).
  dayOfWeek | The day of the week on which this rule occurs.
  time | The time of that day (number of millis after midnight) when DST ends in local wall time, which is daylight time in this case.
  mode | whether the time is local wall time, local standard time, or UTC time. Default is local wall time.
  after | If true, this rule selects the first dayOfWeek on or after dayOfMonth. If false, this rule selects the last dayOfWeek on or before dayOfMonth.
  status | An UErrorCode

Stable:
  ICU 2.0

## ◆ setEndRule() [2/6]

void icu::SimpleTimeZone::setEndRule | ( | int32_t | month,
|  | int32_t | dayOfMonth,
|  | int32_t | dayOfWeek,
|  | int32_t | time,
|  | UBool | after,
|  | UErrorCode & | status
| ) |  |
| inline

Sets the DST end rule to a weekday before or after a give date within a month, e.g., the first Monday on or after the 8th.

Parameters

  month | The month in which this rule occurs (0-based).
  dayOfMonth | A date within that month (1-based).
  dayOfWeek | The day of the week on which this rule occurs.
  time | The time of that day (number of millis after midnight) when DST ends in local wall time, which is daylight time in this case.
  after | If true, this rule selects the first dayOfWeek on or after dayOfMonth. If false, this rule selects the last dayOfWeek on or before dayOfMonth.
  status | An UErrorCode

Stable:
  ICU 2.0

Definition at line 923 of file simpletz.h.

## ◆ setEndRule() [3/6]

void icu::SimpleTimeZone::setEndRule | ( | int32_t | month,
|  | int32_t | dayOfMonth,
|  | int32_t | time,
|  | TimeMode | mode,
|  | UErrorCode & | status
| ) |  |

Sets the DST end rule to a fixed date within a month.

Parameters

  month | The month in which this rule occurs (0-based).
  dayOfMonth | The date in that month (1-based).
  time | The time of that day (number of millis after midnight) when DST ends in local wall time, which is daylight time in this case.
  mode | whether the time is local wall time, local standard time, or UTC time. Default is local wall time.
  status | An UErrorCode

Stable:
  ICU 2.0

## ◆ setEndRule() [4/6]

void icu::SimpleTimeZone::setEndRule | ( | int32_t | month,
|  | int32_t | dayOfMonth,
|  | int32_t | time,
|  | UErrorCode & | status
| ) |  |
| inline

Sets the DST end rule to a fixed date within a month.

Parameters

  month | The month in which this rule occurs (0-based).
  dayOfMonth | The date in that month (1-based).
  time | The time of that day (number of millis after midnight) when DST ends in local wall time, which is daylight time in this case.
  status | An UErrorCode

Stable:
  ICU 2.0

Definition at line 918 of file simpletz.h.

## ◆ setEndRule() [5/6]

void icu::SimpleTimeZone::setEndRule | ( | int32_t | month,
|  | int32_t | dayOfWeekInMonth,
|  | int32_t | dayOfWeek,
|  | int32_t | time,
|  | TimeMode | mode,
|  | UErrorCode & | status
| ) |  |

Sets the daylight savings ending rule.

For example, if Daylight Savings Time ends at the last (-1) Sunday in October, at 2 AM in standard time. Therefore, you can set the end rule by calling:

       setEndRule(UCAL_OCTOBER, -1, UCAL_SUNDAY, 2*60*60*1000);

Various other types of rules can be specified by manipulating the dayOfWeek and dayOfWeekInMonth parameters. For complete details, see the documentation for setStartRule().

Parameters

  month | the daylight savings ending month. Month is 0-based. eg, 0 for January.
  dayOfWeekInMonth | the daylight savings ending day-of-week-in-month. See setStartRule() for a complete explanation.
  dayOfWeek | the daylight savings ending day-of-week. See setStartRule() for a complete explanation.
  time | the daylight savings ending time. Please see the member description for an example.
  mode | whether the time is local wall time, local standard time, or UTC time. Default is local wall time.
  status | An UErrorCode

Stable:
  ICU 2.0

## ◆ setEndRule() [6/6]

void icu::SimpleTimeZone::setEndRule | ( | int32_t | month,
|  | int32_t | dayOfWeekInMonth,
|  | int32_t | dayOfWeek,
|  | int32_t | time,
|  | UErrorCode & | status
| ) |  |
| inline

Sets the daylight savings ending rule.

For example, if Daylight Savings Time ends at the last (-1) Sunday in October, at 2 AM in standard time. Therefore, you can set the end rule by calling:

       setEndRule(UCAL_OCTOBER, -1, UCAL_SUNDAY, 2*60*60*1000);

Various other types of rules can be specified by manipulating the dayOfWeek and dayOfWeekInMonth parameters. For complete details, see the documentation for setStartRule().

Parameters

  month | the daylight savings ending month. Month is 0-based. eg, 0 for January.
  dayOfWeekInMonth | the daylight savings ending day-of-week-in-month. See setStartRule() for a complete explanation.
  dayOfWeek | the daylight savings ending day-of-week. See setStartRule() for a complete explanation.
  time | the daylight savings ending time. Please see the member description for an example.
  status | An UErrorCode

Stable:
  ICU 2.0

Definition at line 912 of file simpletz.h.

## ◆ setRawOffset()

virtual void icu::SimpleTimeZone::setRawOffset | ( | int32_t | offsetMillis | ) |
| overridevirtual

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).

Parameters

  offsetMillis | The new raw GMT offset for this time zone.

Stable:
  ICU 2.0

Implements icu::TimeZone.

## ◆ setStartRule() [1/6]

void icu::SimpleTimeZone::setStartRule | ( | int32_t | month,
|  | int32_t | dayOfMonth,
|  | int32_t | dayOfWeek,
|  | int32_t | time,
|  | TimeMode | mode,
|  | UBool | after,
|  | UErrorCode & | status
| ) |  |

Sets the DST start rule to a weekday before or after a give date within a month, e.g., the first Monday on or after the 8th.

Parameters

  month | The month in which this rule occurs (0-based).
  dayOfMonth | A date within that month (1-based).
  dayOfWeek | The day of the week on which this rule occurs.
  time | The time of that day (number of millis after midnight) when DST takes effect in local wall time, which is standard time in this case.
  mode | whether the time is local wall time, local standard time, or UTC time. Default is local wall time.
  after | If true, this rule selects the first dayOfWeek on or after dayOfMonth. If false, this rule selects the last dayOfWeek on or before dayOfMonth.
  status | An UErrorCode

Stable:
  ICU 2.0

## ◆ setStartRule() [2/6]

void icu::SimpleTimeZone::setStartRule | ( | int32_t | month,
|  | int32_t | dayOfMonth,
|  | int32_t | dayOfWeek,
|  | int32_t | time,
|  | UBool | after,
|  | UErrorCode & | status
| ) |  |
| inline

Sets the DST start rule to a weekday before or after a give date within a month, e.g., the first Monday on or after the 8th.

Parameters

  month | The month in which this rule occurs (0-based).
  dayOfMonth | A date within that month (1-based).
  dayOfWeek | The day of the week on which this rule occurs.
  time | The time of that day (number of millis after midnight) when DST takes effect in local wall time, which is standard time in this case.
  after | If true, this rule selects the first dayOfWeek on or after dayOfMonth. If false, this rule selects the last dayOfWeek on or before dayOfMonth.
  status | An UErrorCode

Stable:
  ICU 2.0

Definition at line 906 of file simpletz.h.

## ◆ setStartRule() [3/6]

void icu::SimpleTimeZone::setStartRule | ( | int32_t | month,
|  | int32_t | dayOfMonth,
|  | int32_t | time,
|  | TimeMode | mode,
|  | UErrorCode & | status
| ) |  |

Sets the DST start rule to a fixed date within a month.

Parameters

  month | The month in which this rule occurs (0-based).
  dayOfMonth | The date in that month (1-based).
  time | The time of that day (number of millis after midnight) when DST takes effect in local wall time, which is standard time in this case.
  mode | whether the time is local wall time, local standard time, or UTC time. Default is local wall time.
  status | An UErrorCode

Stable:
  ICU 2.0

## ◆ setStartRule() [4/6]

void icu::SimpleTimeZone::setStartRule | ( | int32_t | month,
|  | int32_t | dayOfMonth,
|  | int32_t | time,
|  | UErrorCode & | status
| ) |  |
| inline

Sets the DST start rule to a fixed date within a month.

Parameters

  month | The month in which this rule occurs (0-based).
  dayOfMonth | The date in that month (1-based).
  time | The time of that day (number of millis after midnight) when DST takes effect in local wall time, which is standard time in this case.
  status | An UErrorCode

Stable:
  ICU 2.0

Definition at line 900 of file simpletz.h.

## ◆ setStartRule() [5/6]

void icu::SimpleTimeZone::setStartRule | ( | int32_t | month,
|  | int32_t | dayOfWeekInMonth,
|  | int32_t | dayOfWeek,
|  | int32_t | time,
|  | TimeMode | mode,
|  | UErrorCode & | status
| ) |  |

Sets the daylight savings starting rule.

For example, in the U.S., Daylight Savings Time starts at the second Sunday in March, at 2 AM in standard time. Therefore, you can set the start rule by calling: setStartRule(UCAL_MARCH, 2, UCAL_SUNDAY, 2*60*60*1000); The dayOfWeekInMonth and dayOfWeek parameters together specify how to calculate the exact starting date. Their exact meaning depend on their respective signs, allowing various types of rules to be constructed, as follows:

- If both dayOfWeekInMonth and dayOfWeek are positive, they specify the day of week in the month (e.g., (2, WEDNESDAY) is the second Wednesday of the month).
- If dayOfWeek is positive and dayOfWeekInMonth is negative, they specify the day of week in the month counting backward from the end of the month. (e.g., (-1, MONDAY) is the last Monday in the month)
- If dayOfWeek is zero and dayOfWeekInMonth is positive, dayOfWeekInMonth specifies the day of the month, regardless of what day of the week it is. (e.g., (10, 0) is the tenth day of the month)
- If dayOfWeek is zero and dayOfWeekInMonth is negative, dayOfWeekInMonth specifies the day of the month counting backward from the end of the month, regardless of what day of the week it is (e.g., (-2, 0) is the next-to-last day of the month).
- If dayOfWeek is negative and dayOfWeekInMonth is positive, they specify the first specified day of the week on or after the specified day of the month. (e.g., (15, -SUNDAY) is the first Sunday after the 15th of the month [or the 15th itself if the 15th is a Sunday].)
- If dayOfWeek and DayOfWeekInMonth are both negative, they specify the last specified day of the week on or before the specified day of the month. (e.g., (-20, -TUESDAY) is the last Tuesday before the 20th of the month [or the 20th itself if the 20th is a Tuesday].)

Parameters

  month | the daylight savings starting month. Month is 0-based. eg, 0 for January.
  dayOfWeekInMonth | the daylight savings starting day-of-week-in-month. Please see the member description for an example.
  dayOfWeek | the daylight savings starting day-of-week. Please see the member description for an example.
  time | the daylight savings starting time. Please see the member description for an example.
  mode | whether the time is local wall time, local standard time, or UTC time. Default is local wall time.
  status | An UErrorCode

Stable:
  ICU 2.0

## ◆ setStartRule() [6/6]

void icu::SimpleTimeZone::setStartRule | ( | int32_t | month,
|  | int32_t | dayOfWeekInMonth,
|  | int32_t | dayOfWeek,
|  | int32_t | time,
|  | UErrorCode & | status
| ) |  |
| inline

Sets the daylight savings starting rule.

For example, in the U.S., Daylight Savings Time starts at the second Sunday in March, at 2 AM in standard time. Therefore, you can set the start rule by calling: setStartRule(UCAL_MARCH, 2, UCAL_SUNDAY, 2*60*60*1000); The dayOfWeekInMonth and dayOfWeek parameters together specify how to calculate the exact starting date. Their exact meaning depend on their respective signs, allowing various types of rules to be constructed, as follows:

- If both dayOfWeekInMonth and dayOfWeek are positive, they specify the day of week in the month (e.g., (2, WEDNESDAY) is the second Wednesday of the month).
- If dayOfWeek is positive and dayOfWeekInMonth is negative, they specify the day of week in the month counting backward from the end of the month. (e.g., (-1, MONDAY) is the last Monday in the month)
- If dayOfWeek is zero and dayOfWeekInMonth is positive, dayOfWeekInMonth specifies the day of the month, regardless of what day of the week it is. (e.g., (10, 0) is the tenth day of the month)
- If dayOfWeek is zero and dayOfWeekInMonth is negative, dayOfWeekInMonth specifies the day of the month counting backward from the end of the month, regardless of what day of the week it is (e.g., (-2, 0) is the next-to-last day of the month).
- If dayOfWeek is negative and dayOfWeekInMonth is positive, they specify the first specified day of the week on or after the specified day of the month. (e.g., (15, -SUNDAY) is the first Sunday after the 15th of the month [or the 15th itself if the 15th is a Sunday].)
- If dayOfWeek and DayOfWeekInMonth are both negative, they specify the last specified day of the week on or before the specified day of the month. (e.g., (-20, -TUESDAY) is the last Tuesday before the 20th of the month [or the 20th itself if the 20th is a Tuesday].)

Parameters

  month | the daylight savings starting month. Month is 0-based. eg, 0 for January.
  dayOfWeekInMonth | the daylight savings starting day-of-week-in-month. Please see the member description for an example.
  dayOfWeek | the daylight savings starting day-of-week. Please see the member description for an example.
  time | the daylight savings starting time. Please see the member description for an example.
  status | An UErrorCode

Stable:
  ICU 2.0

Definition at line 894 of file simpletz.h.

## ◆ setStartYear()

void icu::SimpleTimeZone::setStartYear | ( | int32_t | year | ) |

Sets the daylight savings starting year, that is, the year this time zone began observing its specified daylight savings time rules.

The time zone is considered not to observe daylight savings time prior to that year; SimpleTimeZone doesn't support historical daylight-savings-time rules.

Parameters

  year | the daylight savings starting year.

Stable:
  ICU 2.0

## ◆ useDaylightTime()

virtual UBool icu::SimpleTimeZone::useDaylightTime | ( |  | ) | const
| overridevirtual

Queries if this TimeZone uses Daylight Savings Time.

Returns
  True if this TimeZone uses Daylight Savings Time; false otherwise.

Stable:
  ICU 2.0

Implements icu::TimeZone.

The documentation for this class was generated from the following file:

- i18n/unicode/simpletz.h