xtd::time_zone_info::adjustement_rule Class Reference

Inheritance diagram for xtd::time_zone_info::adjustement_rule:

Definition

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

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

Inheritance

xtd::object → xtd::adjustement_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
const xtd::date_time &	date_end () const noexcept
	Gets the date when the adjustment rule ceases to be in effect.
const xtd::date_time &	date_start () const noexcept
	Gets the date when the adjustment rule takes effect.
xtd::time_span	daylight_delta () const noexcept
	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).
transition_time	daylight_transition_end () const noexcept
	Gets information about the annual transition from daylight saving time back to standard time.
transition_time	daylight_transition_start () const noexcept
	Gets information about the annual transition from standard time to daylight saving time.

Public Methods
bool	equals (const adjustement_rule &ar) const noexcept override
virtual bool	equals (const object &obj) const noexcept
	Determines whether the specified object is equal to the current object.
template<typename object_a_t , typename object_b_t >
static bool	equals (const object_a_t &object_a, const object_b_t &object_b) noexcept
	Determines whether the specified object instances are considered equal.

Additional Inherited Members
Public Member Functions inherited from xtd::iequatable< adjustement_rule >
virtual bool	equals (const adjustement_rule &) const noexcept=0
	Indicates whether the current object is equal to another object of the same type.
Public Member Functions inherited from xtd::object
	object ()=default
	Create a new instance of the ultimate base class object.
virtual size_t	get_hash_code () const noexcept
	Serves as a hash function for a particular type.
virtual type_object	get_type () const noexcept
	Gets the type of the current instance.
template<typename object_t >
xtd::uptr< object_t >	memberwise_clone () const
	Creates a shallow copy of the current object.
virtual xtd::string	to_string () const noexcept
	Returns a xtd::string that represents the current object.
Static Public Member Functions inherited from xtd::object
template<typename object_a_t , typename object_b_t >
static bool	equals (const object_a_t &object_a, const object_b_t &object_b) noexcept
	Determines whether the specified object instances are considered equal.
template<typename object_a_t , typename object_b_t >
static bool	reference_equals (const object_a_t &object_a, const object_b_t &object_b) noexcept
	Determines whether the specified object instances are the same instance.

Member Function Documentation

date_end()

const xtd::date_time & xtd::time_zone_info::adjustement_rule::date_end ( ) const

noexcept

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::adjustement_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::adjustement_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()

const xtd::date_time & xtd::time_zone_info::adjustement_rule::date_start ( ) const

noexcept

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::adjustement_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::adjustement_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()

xtd::time_span xtd::time_zone_info::adjustement_rule::daylight_delta ( ) const

noexcept

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::adjustement_rule::daylight_delta property can range from 14 hours to -14 hours.

Note

The xtd::time_zone_info::adjustement_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::adjustement_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()

transition_time xtd::time_zone_info::adjustement_rule::daylight_transition_end ( ) const

noexcept

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()

transition_time xtd::time_zone_info::adjustement_rule::daylight_transition_start ( ) const

noexcept

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]

virtual bool xtd::object::equals ( const object &  obj ) const

virtualnoexcept

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.

Examples

The following code example compares the current instance with another object.

#include <xtd/console>
 
using namespace xtd;
 
auto main() -> int {
  auto object1 = new_ptr<object>();
  auto object2 = new_ptr<object>();
  
  auto object3 = object2;
  console::write_line(object1->equals(*object3));
  console::write_line(*object1 == *object3);
  object3 = object1;
  console::write_line(object1->equals(*object3));
  console::write_line(*object1 == *object3);
}
 
// This code produces the following output :
//
// false
// false
// true
// true

Reimplemented from xtd::object.

equals() [2/2]

template<typename object_a_t , typename object_b_t >

static bool xtd::object::equals ( const object_a_t &  object_a, const object_b_t &  object_b  )

inlinestaticnoexcept

Determines whether the specified object instances are considered equal.

Parameters

object_a	The first object to compare.
object_b	The second object to compare.

Returns

true if object_a is the same instance as object_b or if both are null references or if object_a(object_b) returns true. otherwise, false.

Examples

The following code example compares different objects.

#include <xtd/console>
 
using namespace xtd;
 
auto main() -> int {
  string s1 = "Tom";
  string s2 = "Carol";
  console::write_line("object::equals(\"{0}\", \"{1}\") => {2}", s1, s2, object::equals(s1, s2));
  
  s1 = "Tom";
  s2 = "Tom";
  console::write_line("object::equals(\"{0}\", \"{1}\") => {2}", s1, s2, object::equals(s1, s2));
  
  s1 = "";
  s2 = "Tom";
  console::write_line("object::equals(\"{0}\", \"{1}\") => {2}", s1, s2, object::equals(s1, s2));
  
  s1 = "Carol";
  s2 = "";
  console::write_line("object::equals(\"{0}\", \"{1}\") => {2}", s1, s2, object::equals(s1, s2));
  
  s1 = "";
  s2 = "";
  console::write_line("object::equals(\"{0}\", \"{1}\") => {2}", s1, s2, object::equals(s1, s2));
}
 
// This code produces the following output :
//
// object::equals("Tom", "Carol") => false
// object::equals("Tom", "Tom") => true
// object::equals("", "Tom") => false
// object::equals("Carol", "") => false
// object::equals("", "") => true

---

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

• xtd.core/include/xtd/time_zone_info.h