# RuleBasedTimeZone Class Reference

a BasicTimeZone subclass implemented in terms of InitialTimeZoneRule and TimeZoneRule instances More...

`#include <rbtz.h>`

Inheritance diagram for RuleBasedTimeZone:

## Public Member Functions
| RuleBasedTimeZone (const UnicodeString &id, InitialTimeZoneRule *initialRule)
| Constructs a `RuleBasedTimeZone` object with the ID and the `InitialTimeZoneRule`.
| RuleBasedTimeZone (const RuleBasedTimeZone &source)
| Copy constructor.
virtual | ~RuleBasedTimeZone ()
| Destructor.
RuleBasedTimeZone & | operator= (const RuleBasedTimeZone &right)
| Assignment operator.
virtual UBool | operator== (const TimeZone &that) const
| Return true if the given `TimeZone` objects are semantically equal.
virtual UBool | operator!= (const TimeZone &that) const
| Return true if the given `TimeZone` objects are semantically unequal.
void | addTransitionRule (TimeZoneRule *rule, UErrorCode &status)
| Adds the `TimeZoneRule` which represents time transitions.
void | complete (UErrorCode &status)
| Makes the `TimeZoneRule` ready to handle actual timezone calcuation APIs.
virtual TimeZone * | clone (void) const
| Clones TimeZone objects polymorphically.
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
| 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.
virtual int32_t | getOffset (uint8_t era, int32_t year, int32_t month, int32_t day, uint8_t dayOfWeek, int32_t millis, int32_t monthLength, UErrorCode &status) const
| Gets the time zone offset, for current date, modified in case of daylight savings.
virtual void | getOffset (UDate date, UBool local, int32_t &rawOffset, int32_t &dstOffset, UErrorCode &ec) const
| Returns the time zone raw and GMT offset for the given moment in time.
virtual void | setRawOffset (int32_t offsetMillis)
| 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).
virtual int32_t | getRawOffset (void) const
| 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).
virtual UBool | useDaylightTime (void) const
| Queries if this time zone uses daylight savings time.
virtual UBool | inDaylightTime (UDate date, UErrorCode &status) const
| Queries if the given date is in daylight savings time in this time zone.
virtual UBool | hasSameRules (const TimeZone &other) const
| Returns true if this zone has the same rule and offset as another zone.
virtual UBool | getNextTransition (UDate base, UBool inclusive, TimeZoneTransition &result)
| Gets the first time zone transition after the base time.
virtual UBool | getPreviousTransition (UDate base, UBool inclusive, TimeZoneTransition &result)
| Gets the most recent time zone transition before the base time.
virtual int32_t | countTransitionRules (UErrorCode &status)
| 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`.
virtual void | getTimeZoneRules (const InitialTimeZoneRule *&initial, const TimeZoneRule *trsrules[], int32_t &trscount, UErrorCode &status)
| Gets the `InitialTimeZoneRule` and the set of `TimeZoneRule` which represent time transitions for this time zone.
virtual void | getOffsetFromLocal (UDate date, int32_t nonExistingTimeOpt, int32_t duplicatedTimeOpt, int32_t &rawOffset, int32_t &dstOffset, UErrorCode &status)
| Get time zone offsets from local wall time.
virtual UClassID | getDynamicClassID (void) const
| Returns a unique class ID POLYMORPHICALLY.
## Static Public Member Functions
static UClassID | getStaticClassID (void)
| Return the class ID for this class.

## Detailed Description

a BasicTimeZone subclass implemented in terms of InitialTimeZoneRule and TimeZoneRule instances

See also:
  BasicTimeZone
  InitialTimeZoneRule
  TimeZoneRule

Definition at line 34 of file rbtz.h.

## Constructor & Destructor Documentation

RuleBasedTimeZone::RuleBasedTimeZone | ( | const UnicodeString & | id,
|  | InitialTimeZoneRule * | initialRule |
| ) |  |  |

Constructs a `RuleBasedTimeZone` object with the ID and the `InitialTimeZoneRule`.

The input `InitialTimeZoneRule` is adopted by this `RuleBasedTimeZone`, thus the caller must not delete it.

Parameters:

  | id | The time zone ID.
  | initialRule | The initial time zone rule.

Stable:
  ICU 3.8

RuleBasedTimeZone::RuleBasedTimeZone | ( | const RuleBasedTimeZone & | source | ) |

Copy constructor.

Parameters:

  | source | The RuleBasedTimeZone object to be copied.

Stable:
  ICU 3.8

virtual RuleBasedTimeZone::~RuleBasedTimeZone | ( |  | ) | `[virtual]`

Destructor.

Stable:
  ICU 3.8

## Member Function Documentation

void RuleBasedTimeZone::addTransitionRule | ( | TimeZoneRule * | rule,
|  | UErrorCode & | status |
| ) |  |  |

Adds the `TimeZoneRule` which represents time transitions.

The `TimeZoneRule` must have start times, that is, the result of isTransitionRule() must be true. Otherwise, U_ILLEGAL_ARGUMENT_ERROR is set to the error code. The input `TimeZoneRule` is adopted by this `RuleBasedTimeZone` on successful completion of this method, thus, the caller must not delete it when no error is returned. After all rules are added, the caller must call complete() method to make this `RuleBasedTimeZone` ready to handle common time zone functions.

Parameters:

  | rule | The `TimeZoneRule`.
  | status | Output param to filled in with a success or an error.

Stable:
  ICU 3.8

virtual TimeZone* RuleBasedTimeZone::clone | ( | void |  | ) | const`[virtual]`

Clones TimeZone objects polymorphically.

Clients are responsible for deleting the TimeZone object cloned.

Returns:
  A new copy of this TimeZone object.

Stable:
  ICU 3.8

Implements TimeZone.

void RuleBasedTimeZone::complete | ( | UErrorCode & | status | ) |

Makes the `TimeZoneRule` ready to handle actual timezone calcuation APIs.

This method collects time zone rules specified by the caller via the constructor and addTransitionRule() and builds internal structure for making the object ready to support time zone APIs such as getOffset(), getNextTransition() and others.

Parameters:

  | status | Output param to filled in with a success or an error.

Stable:
  ICU 3.8

virtual int32_t RuleBasedTimeZone::countTransitionRules | ( | UErrorCode & | status | ) | `[virtual]`

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 BasicTimeZone.

virtual UClassID RuleBasedTimeZone::getDynamicClassID | ( | void |  | ) | const`[virtual]`

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 3.8

Implements TimeZone.

virtual UBool RuleBasedTimeZone::getNextTransition | ( | UDate | base,
|  | UBool | inclusive,
|  | TimeZoneTransition & | result |
| ) |  |  | `[virtual]`

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 BasicTimeZone.

virtual void RuleBasedTimeZone::getOffset | ( | UDate | date,
|  | UBool | local,
|  | int32_t & | rawOffset,
|  | int32_t & | dstOffset,
|  | UErrorCode & | ec |
| ) |  |  | const`[virtual]`

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().

Parameters:

  | 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'.
  | local | if true, `date' is local wall time; otherwise it is in GMT time.
  | rawOffset | output parameter to receive the raw offset, that is, the offset not including DST adjustments
  | 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.
  | ec | input-output error code

Stable:
  ICU 3.8

Reimplemented from TimeZone.

virtual int32_t RuleBasedTimeZone::getOffset | ( | uint8_t | era,
|  | int32_t | year,
|  | int32_t | month,
|  | int32_t | day,
|  | uint8_t | dayOfWeek,
|  | int32_t | millis,
|  | int32_t | monthLength,
|  | 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.

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.

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, local standard time
  | monthLength | The length of the given month in days.
  | status | Output param to filled in with a success or an error.

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

Stable:
  ICU 3.8

Implements TimeZone.

virtual int32_t RuleBasedTimeZone::getOffset | ( | uint8_t | era,
|  | int32_t | year,
|  | int32_t | month,
|  | int32_t | day,
|  | uint8_t | dayOfWeek,
|  | int32_t | millis,
|  | UErrorCode & | status |
| ) |  |  | const`[virtual]`

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.

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.

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, local standard time
  | status | Output param to filled in with a success or an error.

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

Stable:
  ICU 3.8

Implements TimeZone.

virtual void RuleBasedTimeZone::getOffsetFromLocal | ( | UDate | date,
|  | int32_t | nonExistingTimeOpt,
|  | int32_t | duplicatedTimeOpt,
|  | int32_t & | rawOffset,
|  | int32_t & | dstOffset,
|  | UErrorCode & | status |
| ) |  |  | `[virtual]`

Get time zone offsets from local wall time.

Internal:
  Do not use. This API is for internal use only.

Reimplemented from BasicTimeZone.

virtual UBool RuleBasedTimeZone::getPreviousTransition | ( | UDate | base,
|  | UBool | inclusive,
|  | TimeZoneTransition & | result |
| ) |  |  | `[virtual]`

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 BasicTimeZone.

virtual int32_t RuleBasedTimeZone::getRawOffset | ( | void |  | ) | const`[virtual]`

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 3.8

Implements TimeZone.

static UClassID RuleBasedTimeZone::getStaticClassID | ( | void |  | ) | `[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() ==
     .       erived::getStaticClassID()) ...

Returns:
  The class ID for all objects of this class.

Stable:
  ICU 3.8

Reimplemented from TimeZone.

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

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-NULL `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 BasicTimeZone.

virtual UBool RuleBasedTimeZone::hasSameRules | ( | const TimeZone & | other | ) | const`[virtual]`

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.

Parameters:

  | other | the `TimeZone` object to be compared with

Returns:
  true if the given zone is the same as this one, with the possible exception of the ID

Stable:
  ICU 3.8

virtual UBool RuleBasedTimeZone::inDaylightTime | ( | UDate | date,
|  | UErrorCode & | status |
| ) |  |  | const`[virtual]`

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.

Parameters:

  | date | the given UDate.
  | status | Output param filled in with success/error code.

Returns:
  true if the given date is in daylight savings time, false, otherwise.

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

Implements TimeZone.

virtual UBool RuleBasedTimeZone::operator!= | ( | const TimeZone & | that | ) | const`[virtual]`

Return true if the given `TimeZone` objects are semantically unequal.

Objects of different subclasses are considered unequal.

Parameters:

  | that | The object to be compared with.

Returns:
  true if the given `TimeZone` objects are semantically unequal.

Stable:
  ICU 3.8

RuleBasedTimeZone& RuleBasedTimeZone::operator= | ( | const RuleBasedTimeZone & | right | ) |

Assignment operator.

Parameters:

  | right | The object to be copied.

Stable:
  ICU 3.8

Reimplemented from TimeZone.

virtual UBool RuleBasedTimeZone::operator== | ( | const TimeZone & | that | ) | const`[virtual]`

Return true if the given `TimeZone` objects are semantically equal.

Objects of different subclasses are considered unequal.

Parameters:

  | that | The object to be compared with.

Returns:
  true if the given `TimeZone` objects are semantically equal.

Stable:
  ICU 3.8

virtual void RuleBasedTimeZone::setRawOffset | ( | int32_t | offsetMillis | ) | `[virtual]`

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 3.8

Implements TimeZone.

virtual UBool RuleBasedTimeZone::useDaylightTime | ( | void |  | ) | const`[virtual]`

Queries if this time zone uses daylight savings time.

Returns:
  true if this time zone uses daylight savings time, false, otherwise.

Stable:
  ICU 3.8

Implements TimeZone.

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

- rbtz.h

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