xtd::time_zone_info::adjustment_rule Class Reference

Inheritance diagram for xtd::time_zone_info::adjustment_rule:

Definition

Provides information about a time zone adjustment, such as the transition to and from daylight saving time.

class adjustment_rule : public xtd::iequatable<adjustment_rule>, public xtd::object

Inheritance

xtd::object → xtd::adjustment_rule

Implements

xtd::iequatable <>

Namespace

xtd

Library

xtd.core

Remarks

The xtd::time_zone_info::adjustment_rule class defines the effective start and end dates of a particular time change to and from daylight saving time, respectively, as well as its delta (the exact amount by which the adjustment causes the time zone's standard time to change). In addition, two properties return xtd::txtd::time_zone_info::transition_time objects that define when each transition to and from standard time occurs.

Note

An instance of the xtd::time_zone_info::adjustment_rule class is immutable. Once an object has been created, its values cannot be modified.

Remarks

To create a xtd::time_zone_info::adjustment_rule object, call the static xtd::time_zone_info::adjustment_rule::create_adjustment_rule method. You can then supply an array of xtd::time_zone_info::adjustment_rule objects to two of the overloads of the xtd::time_zone_info::create_custom_time_zone method. To retrieve the adjustment rules of a particular time zone, call its xtd::time_zone_info::get_adjustment_rules method, which returns an array of xtd::time_zone_info::adjustment_rule objects.

Public Properties
auto	date_end () const noexcept -> const xtd::date_time &
	Gets the date when the adjustment rule ceases to be in effect.
auto	date_start () const noexcept -> const xtd::date_time &
	Gets the date when the adjustment rule takes effect.
auto	daylight_delta () const noexcept -> xtd::time_span
	Gets the amount of time that is required to form the time zone's daylight saving time. This amount of time is added to the time zone's offset from Coordinated Universal Time (UTC).
auto	daylight_transition_end () const noexcept -> transition_time
	Gets information about the annual transition from daylight saving time back to standard time.
auto	daylight_transition_start () const noexcept -> transition_time
	Gets information about the annual transition from standard time to daylight saving time.

Public Methods
auto	equals (const xtd::object &obj) const noexcept -> bool override
	Determines whether the specified object is equal to the current object.
auto	equals (const adjustment_rule &ar) const noexcept -> bool override
	Determines whether the specified object is equal to the current object.
auto	get_hash_code () const noexcept -> xtd::usize override
	Serves as a hash function for a particular type.

Additional Inherited Members
virtual auto	equals (const adjustment_rule &) const noexcept -> bool=0
	Indicates whether the current object is equal to another object of the same type.
	object ()=default
	Create a new instance of the ultimate base class object.
virtual auto	get_type () const noexcept -> type_object
	Gets the type of the current instance.
template<typename object_t>
auto	memberwise_clone () const -> xtd::unique_ptr_object< object_t >
	Creates a shallow copy of the current object.
virtual auto	to_string () const -> xtd::string
	Returns a xtd::string that represents the current object.
template<typename object_a_t, typename object_b_t>
static auto	equals (const object_a_t &object_a, const object_b_t &object_b) noexcept -> bool
	Determines whether the specified object instances are considered equal.
template<typename object_a_t, typename object_b_t>
static auto	reference_equals (const object_a_t &object_a, const object_b_t &object_b) noexcept -> bool
	Determines whether the specified object instances are the same instance.

Member Function Documentation

date_end()

auto xtd::time_zone_info::adjustment_rule::date_end ( ) const -> const xtd::date_time &

nodiscardnoexcept

Gets the date when the adjustment rule ceases to be in effect.

Returns

A xtd::date_time value that indicates the end date of the adjustment rule.

Remarks

The value of the xtd::time_zone_info::adjustment_rule::date_end property is a date value without a time component.

Because the end date of the current adjustment rule is typically not known, you can assign

date_time::max_value().date() 

to the xtd::time_zone_info::adjustment_rule::date_end property when you create a custom adjustment rule.

Warning

Unless there is a compelling reason to do otherwise, you should define the adjustment rule's end date to occur within the time interval during which the time zone observes standard time. Unless there is a compelling reason to do so, you should not define the adjustment rule's end date to occur within the time interval during which the time zone observes daylight saving time. For example, if a time zone's transition from daylight saving time occurs on the third Sunday of March and its transition to daylight saving time occurs on the first Sunday of October, the effective end date of the adjustment rule should not be December 31 of a particular year, since that date occurs within the period of daylight saving time.

date_start()

auto xtd::time_zone_info::adjustment_rule::date_start ( ) const -> const xtd::date_time &

nodiscardnoexcept

Gets the date when the adjustment rule takes effect.

Returns

A xtd::date_time value that indicates when the adjustment rule takes effect.

Remarks

The value of the xtd::time_zone_info::adjustment_rule::date_start property is a date value without a time component. It defines the date on which a particular adjustment rule goes into effect. This is the date in which a set of transitions (which typically are defined by one transition to daylight savings time and one transition back to standard time) go into effect. For example, an adjustment rule might go into effect on January 1, 2017, that provides for a transition to daylight savings time on the second Sunday of March and for a transition back to standard time on the first Sunday of November. Note that the starting date of the adjustment rule is not tied to the date of the first transition.

You can assign

date_time::min_value().date() 

to the xtd::time_zone_info::adjustment_rule::date_end property when you create a custom adjustment rule for use in a time zone-aware application that does not have to work with historic time zone information.

Warning

Unless there is a compelling reason to do otherwise, you should define the adjustment rule's start date to occur within the time interval during which the time zone observes standard time. Unless there is a compelling reason to do so, you should not define the adjustment rule's start date to occur within the time interval during which the time zone observes daylight saving time. For example, if a time zone's transition from daylight saving time occurs on the third Sunday of March and its transition to daylight saving time occurs on the first Sunday of October, the effective start date of the adjustment rule should not be January 1 of a particular year, since that date occurs within the period of daylight saving time.

daylight_delta()

auto xtd::time_zone_info::adjustment_rule::daylight_delta ( ) const -> xtd::time_span

nodiscardnoexcept

Gets the amount of time that is required to form the time zone's daylight saving time. This amount of time is added to the time zone's offset from Coordinated Universal Time (UTC).

Returns

A xtd::time_span object that indicates the amount of time to add to the standard time changes as a result of the adjustment rule.

Remarks

The following formula defines a time zone's daylight saving time:

time_tone_time = base_utc_offset + daylight_delta + utc_time

The value of the xtd::time_zone_info::adjustment_rule::daylight_delta property can range from 14 hours to -14 hours.

Note

The xtd::time_zone_info::adjustment_rule::daylight_delta property measures the difference between the time zone's standard time and its daylight saving time. It does not apply to changes in a time zone's standard offset from Coordinated Universal Time (UTC). To represent a time zone that has changed its standard time offset from UTC, you must call the CreateCustomTimeZone method to create a new time zone.

Remarks

The most common value of the xtd::time_zone_info::adjustment_rule::daylight_delta property is 1.0 hours. The application of the daylight saving time adjustment rule increases the time zone's offset from Coordinated Universal Time (UTC) by one hour.

daylight_transition_end()

auto xtd::time_zone_info::adjustment_rule::daylight_transition_end ( ) const -> transition_time

nodiscardnoexcept

Gets information about the annual transition from daylight saving time back to standard time.

Returns

A xtd::time_zone_info::transition_time object that defines the annual transition from daylight saving time back to the time zone's standard time.

Remarks

The xtd::time_zone_info::transition_time object returned by the xtd::time_zone_info::transition_time::daylight_transition_end property defines either a fixed-date rule or a floating-date rule for the return to standard time. A fixed-date rule provides the month, day, and time of day on which the transition occurs. A floating-date rule provides the month, week, day of the week, and time of day on which the transition occurs.

daylight_transition_start()

auto xtd::time_zone_info::adjustment_rule::daylight_transition_start ( ) const -> transition_time

nodiscardnoexcept

Gets information about the annual transition from standard time to daylight saving time.

Returns

A xtd::time_zone_info::transition_time object that defines the annual transition from a time zone's standard time to daylight saving time.

Remarks

The xtd::time_zone_info::transition_time object returned by the xtd::time_zone_info::transition_time::daylight_transition_start property defines either a fixed-date rule or a floating-date rule for the transition to daylight saving time. A fixed-date rule provides the month, day, and time of day on which the transition occurs. A floating-date rule provides the month, the week, the day of the week, and the time of day on which the transition occurs.

equals() [1/2]

auto xtd::time_zone_info::adjustment_rule::equals ( const xtd::object & obj ) const -> bool

nodiscardoverridevirtualnoexcept

Determines whether the specified object is equal to the current object.

Parameters

obj	The object to compare with the current object.

Returns

true if the specified object is equal to the current object. otherwise, false.

Reimplemented from xtd::object.

equals() [2/2]

auto xtd::time_zone_info::adjustment_rule::equals ( const adjustment_rule & ar ) const -> bool

nodiscardoverridenoexcept

Determines whether the specified object is equal to the current object.

Parameters

ar	The object to compare with the current object.

Returns

true if the specified object is equal to the current object. otherwise, false.

get_hash_code()

auto xtd::time_zone_info::adjustment_rule::get_hash_code ( ) const -> xtd::usize

nodiscardoverridevirtualnoexcept

Serves as a hash function for a particular type.

Returns

A hash code for the current object.

Reimplemented from xtd::object.

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

• xtd.core/include/xtd/time_zone_info.hpp