std::chrono::zoned_time

 

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Date and time library

Time point time_point (C++11) clock_time_conversion (C++20)   clock_cast (C++20) Duration duration (C++11) Clocks system_clock (C++11) steady_clock (C++11) is_clock (C++20) utc_clock (C++20) tai_clock (C++20) high_resolution_clock (C++11) gps_clock (C++20) file_clock (C++20) local_t (C++20) Time of day is_amis_pm (C++20)(C++20) make12make24 (C++20)(C++20) hh_mm_ss (C++20)

Calendar day (C++20) month (C++20) year (C++20) weekday (C++20) operator/ (C++20) year_month_day (C++20) year_month_day_last (C++20) year_month_weekday (C++20) year_month_weekday_last (C++20)   weekday_indexed (C++20) weekday_last (C++20) month_day (C++20) month_day_last (C++20) month_weekday (C++20) month_weekday_last (C++20) year_month (C++20) last_speclast (C++20)(C++20) chrono I/O parse (C++20)

Time zone tzdb (C++20) tzdb_list (C++20) get_tzdbget_tzdb_listreload_tzdbremote_version (C++20)(C++20)(C++20)(C++20) sys_info (C++20) local_info (C++20) nonexistent_local_time (C++20) ambiguous_local_time (C++20) locate_zone (C++20) current_zone (C++20) time_zone (C++20) choose (C++20) zoned_traits (C++20) zoned_time (C++20) time_zone_link (C++20) leap_second (C++20) leap_second_info (C++20) get_leap_second_info (C++20) C-style date and time

 

std::chrono::zoned_time

Member functions

zoned_time::zoned_time

zoned_time::operator=

zoned_time::get_time_zone

zoned_time::get_sys_timezoned_time::operator sys_time

zoned_time::get_local_timezoned_time::operator local_time

zoned_time::get_info

Nonmember functions

operator==

operator<<

Helper classes

formatter<std::chrono::zoned_time>

hash<std::chrono::zoned_time> (C++26)

Deduction guides

 

Defined in header <chrono>
template<     class Duration,     class TimeZonePtr =conststd::chrono::time_zone* >class zoned_time;		(since C++20)
using zoned_seconds = std::chrono::zoned_time<std::chrono::seconds>;		(since C++20)

The class zoned_time represents a logical pairing of a time zone and a std::chrono::time_point whose resolution is Duration.

An invariant of zoned_time is that it always refers to a valid time zone and represents an existing and unambiguous time point in that time zone. Consistent with this invariant, zoned_time has no move constructor or move assignment operator; attempts to move a zoned_time will perform a copy.

The program is ill-formed if Duration is not a specialization of std::chrono::duration.

The template parameter TimeZonePtr allows users to supply their own time zone pointer types and further customize the behavior of zoned_time via std::chrono::zoned_traits. Custom time zone types need not support all the operations supported by std::chrono::time_zone, only those used by the functions actually called on the zoned_time.

TimeZonePtr must be MoveConstructible. Move-only TimeZonePtrs are allowed but difficult to use, as the zoned_time will be immovable and it is not possible to access the stored TimeZonePtr.

Member types

Member type	Definition
duration	std::common_type_t<Duration, std::chrono::seconds>

Member functions

(constructor)	constructs a zoned_time (public member function)
operator=	assigns value to a zoned_time (public member function)
get_time_zone	obtains a copy of the time zone pointer (public member function)
operator local_timeget_local_time	obtains the stored time point as a local_time (public member function)
operator sys_timeget_sys_time	obtains the stored time point as a sys_time (public member function)
get_info	obtain information about the time zone at the stored time point (public member function)

Non-member functions

operator== (C++20)	compares two zoned_time values (function template)
operator<< (C++20)	outputs a zoned_time into a stream (function template)

Helper classes

std::formatter<std::chrono::zoned_time> (C++20)	formatting support for zoned_time (class template specialization)
std::hash<std::chrono::zoned_time> (C++26)	hash support for std::chrono::zoned_time (class template specialization)

Helper specializations

template<class Duration > constexprbool enable_nonlocking_formatter_optimization   <chrono::zoned_time<Duration, const chrono::time_zone*>>=true;		(since C++23)

This specialization of std::enable_nonlocking_formatter_optimization enables efficient implementation of std::print and std::println for printing a chrono::zoned_time object.

Example

Run this code

#include <algorithm>#include <chrono>#include <iomanip>#include <iostream>#include <stdexcept>#include <string_view>   int main(){constexprstd::string_view locations[]={"Africa/Casablanca", "America/Argentina/Buenos_Aires", "America/Barbados", "America/Indiana/Petersburg", "America/Tarasco_Bar", "Antarctica/Casey", "Antarctica/Vostok", "Asia/Magadan", "Asia/Manila", "Asia/Shanghai", "Asia/Tokyo", "Atlantic/Bermuda", "Australia/Darwin", "Europe/Isle_of_Man", "Europe/Laputa", "Indian/Christmas", "Indian/Cocos", "Pacific/Galapagos", };   constexprauto width = std::ranges::max_element(locations, {}, [](constauto& s){return s.length();})->length();   for(constauto location : locations)try{// may throw if 'location' is not in the time zone databaseconst std::chrono::zoned_time zt{location, std::chrono::system_clock::now()};std::cout<<std::setw(width)<< location <<" - Zoned Time: "<< zt <<'\n';}catch(std::runtime_error& ex){std::cout<<"Error: "<< ex.what()<<'\n';}}

Possible output:

 Africa/Casablanca - Zoned Time: 2023-06-29 20:58:34.697449319 +01 America/Argentina/Buenos_Aires - Zoned Time: 2023-06-29 16:58:34.709957354 -03 America/Barbados - Zoned Time: 2023-06-29 15:58:34.709977888 AST America/Indiana/Petersburg - Zoned Time: 2023-06-29 15:58:34.709998072 EDT Error: tzdb: cannot locate zone: America/Tarasco_Bar Antarctica/Casey - Zoned Time: 2023-06-30 06:58:34.710093685 +11 Antarctica/Vostok - Zoned Time: 2023-06-30 01:58:34.710107932 +06 Asia/Magadan - Zoned Time: 2023-06-30 06:58:34.710121831 +11 Asia/Manila - Zoned Time: 2023-06-30 03:58:34.710134751 PST Asia/Shanghai - Zoned Time: 2023-06-30 03:58:34.710153259 CST Asia/Tokyo - Zoned Time: 2023-06-30 04:58:34.710172815 JST Atlantic/Bermuda - Zoned Time: 2023-06-29 16:58:34.710191043 ADT Australia/Darwin - Zoned Time: 2023-06-30 05:28:34.710236720 ACST Europe/Isle_of_Man - Zoned Time: 2023-06-29 20:58:34.710256834 BST Error: tzdb: cannot locate zone: Europe/Laputa Indian/Christmas - Zoned Time: 2023-06-30 02:58:34.710360409 +07 Indian/Cocos - Zoned Time: 2023-06-30 02:28:34.710377520 +0630 Pacific/Galapagos - Zoned Time: 2023-06-29 13:58:34.710389952 -06

See also

time_zone (C++20)

represents a time zone (class)