std::chrono::utc_clock::from_sys

 

C++

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Standard library headers

Named requirements

Feature test macros (C++20)

Language support library

Concepts library (C++20)

Diagnostics library

Memory management library

Metaprogramming library (C++11)

General utilities library

Containers library

Iterators library

Ranges library (C++20)

Algorithms library

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Date and time library

Input/output library

Filesystem library (C++17)

Concurrency support library (C++11)

Execution control library (C++26)

Technical specifications

Symbols index

External libraries

 

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::utc_clock

Member functions

utc_clock::now

utc_clock::to_sys

utc_clock::from_sys

Time point I/O

operator<<

formatter<std::chrono::utc_time>

from_stream

Leap second insertion information

leap_second_info

get_leap_second_info

 

template< class Duration > static std::chrono::utc_time<std::common_type_t<Duration, std::chrono::seconds>>     from_sys( const std::chrono::sys_time<Duration>& t );		(since C++20)

Converts a sys_time t to a utc_time u that represents the same point in time.

u.time_since_epoch() - t.time_since_epoch() is equal to the number of leap seconds that was inserted between t and 1 January 1970. If t is the exact date of a leap second insertion, that leap second is counted as inserted.

Return value

A utc_time representing the same point in time as t.

See also

to_sys [static]	converts utc_time to sys_time (public static member function)
clock_cast (C++20)	convert time points of one clock to another (function template)

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