# std::chrono::zoned_time<Duration,TimeZonePtr>::zoned_time

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< cpp‎ | chrono‎ | zoned time

zoned_time(); | (1) | (since C++20)
zoned_time( const std::chrono::sys_time<Duration>& st ); | (2) | (since C++20)
zoned_time( const zoned_time& other) = default; | (3) | (since C++20)
template< class Duration2 > zoned_time( const std::chrono::zoned_time<Duration2, TimeZonePtr>& other ); | (4) | (since C++20)
explicit zoned_time( TimeZonePtr z ); | (5) | (since C++20)
explicit zoned_time( std::string_view name ); | (6) | (since C++20)
zoned_time( TimeZonePtr z, const std::chrono::sys_time<Duration>& st ); | (7) | (since C++20)
zoned_time( std::string_view name, const std::chrono::sys_time<Duration>& st ); | (8) | (since C++20)
zoned_time( TimeZonePtr z, const std::chrono::local_time<Duration>& tp ); | (9) | (since C++20)
zoned_time( std::string_view name, const std::chrono::local_time<Duration>& tp ); | (10) | (since C++20)
zoned_time( TimeZonePtr z, const std::chrono::local_time<Duration>& tp, std::chrono::choose c ); | (11) | (since C++20)
zoned_time( std::string_view name, const std::chrono::local_time<Duration>& tp, std::chrono::choose c ); | (12) | (since C++20)
template< class Duration2, class TimeZonePtr2 > zoned_time( TimeZonePtr z, const std::chrono::zoned_time<Duration2, TimeZonePtr2>& zt ); | (13) | (since C++20)
template< class Duration2, class TimeZonePtr2 > zoned_time( TimeZonePtr z, const std::chrono::zoned_time<Duration2, TimeZonePtr2>& zt, std::chrono::choose ); | (14) | (since C++20)
template< class Duration2, class TimeZonePtr2 > zoned_time( std::string_view name, const std::chrono::zoned_time<Duration2, TimeZonePtr2>& zt ); | (15) | (since C++20)
template< class Duration2, class TimeZonePtr2 > zoned_time( std::string_view name, const std::chrono::zoned_time<Duration2, TimeZonePtr2>& zt, std::chrono::choose ); | (16) | (since C++20)

Constructs a `zoned_time` object, initializing the stored time zone pointer and time point according to the following table, where `traits` is std::chrono::zoned_traits<TimeZonePtr>:

Overload | Time zone pointer (denoted `zone`) | Time point (a std::chrono::sys_time<duration>) | Notes
--- | --- | --- | ---
(1) | traits::default_zone() | default constructed | (a)
(2) | `st`
(3) | other.get_time_zone() | other.get_sys_time() | (b)
(4) | other.get_time_zone() | other.get_sys_time() | (e)
(5) | std::move(z) | default constructed |
(6) | traits::locate_zone(name) | (c)
(7) | std::move(z) | `st` |
(8) | traits::locate_zone(name) | (c)
(9) | std::move(z) | zone->to_sys(tp) | (d)
(10) | traits::locate_zone(name) | (c,d)
(11) | std::move(z) | zone->to_sys(tp, c) | (d)
(12) | traits::locate_zone(name) | (c,d)
(13-14) | std::move(z) | zt.get_sys_time() | (e)
(15-16) | traits::locate_zone(name) | (c,e)

a) Constructors specified to call traits::default_zone() (1-2) do not participate in overload resolution if that expression is not well-formed.
b) The defaulted copy constructor (3) is defined as deleted if std::is_copy_constructible_v<TimeZonePtr> is false.
c) Constructors with a std::string_view parameter `name` (6,8,10,12,15-16) do not participate in overload resolution if traits::locate_zone(name) is not well-formed or if that expression is not convertible to `TimeZonePtr`.
d) Constructors specified to call zone->to_sys (9-12) do not participate in overload resolution if that call expression is not well-formed or if the result is not convertible to std::chrono::sys_time<duration>.
e) Constructors with a template parameter `Duration2` (4,13-16) do not participate in overload resolution if `Duration2` is not convertible to `Duration`.

The behavior is undefined if the time zone pointer (initialized as described above) does not refer to a time zone.

### Notes

`zoned_time` does not have a move constructor and attempting to move one will perform a copy instead using the defaulted copy constructor (3). Thus, when `TimeZonePtr` is a move-only type, `zoned_time` is immovable: it can be neither moved nor copied.

The constructors (14,16) accept a std::chrono::choose parameter, but that parameter has no effect.

### Example

Run this code

    #include <chrono>
    #include <iostream>
    #include <string_view>

    int main()
    {
        using std::chrono_literals::operator""y;
        using std::operator""sv;

        const auto now = std::chrono::floor<std::chrono::minutes>(std::chrono::system_clock::now());

        {
            std::cout << std::chrono::zoned_time{} << " : default\n";
        }
        {
            constexpr std::string_view location {"America/Phoenix"sv};
            std::cout << std::chrono::zoned_time{ location } << " : " << location << '\n';
        }
        {
            const std::chrono::time_zone* TimeZonePtr = std::chrono::locate_zone("UTC");
            std::cout << std::chrono::zoned_time{ TimeZonePtr } << " : UTC time zone\n";
        }
        {
            constexpr auto location{"Europe/Rome"sv};
            std::cout << std::chrono::zoned_time{ location, std::chrono::local_days{2021y/12/31} }
                      << " : " << location << '\n';
        }
        {
            constexpr auto location {"Europe/Rome"sv};
            constexpr auto some_date = std::chrono::sys_time<std::chrono::days>{2021y/12/31};
            std::cout << std::chrono::zoned_time{ location, some_date } << " : " << location << '\n';
        }
        {
            constexpr auto location {"Europe/Rome"sv};
            std::cout << std::chrono::zoned_time{ location, now } << " : " << location << '\n';
        }
        {
            constexpr auto NewYork {"America/New_York"sv};
            constexpr auto Tokyo {"Asia/Tokyo"sv};
            const std::chrono::zoned_time tz_Tokyo {Tokyo, now};
            const std::chrono::zoned_time tz_NewYork {NewYork, now};
            std::cout << std::chrono::zoned_time{ Tokyo, tz_NewYork } << " : " << Tokyo << '\n';
            std::cout << std::chrono::zoned_time{ NewYork, tz_Tokyo } << " : " << NewYork << '\n';
        }
    }

Possible output:

    1970-01-01 00:00:00 UTC : default
    1969-12-31 17:00:00 MST : America/Phoenix
    1970-01-01 00:00:00 UTC : UTC time zone
    2021-12-31 00:00:00 CET : Europe/Rome
    2021-12-31 01:00:00 CET : Europe/Rome
    2021-09-20 23:04:00 CEST : Europe/Rome
    2021-09-21 06:04:00 JST : Asia/Tokyo
    2021-09-20 17:04:00 EDT : America/New_York

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