std::timespec

 

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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)

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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

 

C-style date and time utilities

Functions

Time manipulation

difftime

time

clock

timespec_get (C++17)

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asctime

ctime

strftime

wcsftime

gmtime

localtime

mktime

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CLOCKS_PER_SEC

Types

tm

time_t

clock_t

timespec (C++17)

 

Defined in header <ctime>
struct timespec;		(since C++17)

See More

Structure holding an interval broken down into seconds and nanoseconds.

Data members

Member	Description
std::time_t tv_sec	whole seconds, the value is >= 0 (public member object)
tv_nsec	nanoseconds, the value is in range [0, 999999999] (public member object)

The declaration order of tv_sec and tv_nsec is unspecified. Implementation may add other data members to timespec.

Notes

The type of tv_nsec is long long on some platforms, which is currently non-conforming in C++, but is allowed in C since C23.

Example

Run this code

#include <ctime>
#include <iostream>

int main()
{
    std::timespec ts;
    std::timespec_get(&ts, TIME_UTC);
    char buff[0x80];
    std::strftime(buff, sizeof buff, "%D %T", std::gmtime(&ts.tv_sec));

//  auto [sec, nsec] = ts; // UB: structured bindings should not be used because the
                           // declaration order and data member list are unspecified

    std::cout << "Current time: " << buff << " (UTC)\n"
              << "Raw timespec.tv_sec: " << ts.tv_sec << '\n'
              << "Raw timespec.tv_nsec: " << ts.tv_nsec << '\n';
}

Possible output:

Current time: 04/06/23 12:03:31 (UTC)
Raw timespec.tv_sec: 1680782611
Raw timespec.tv_nsec: 678437213

See also

timespec_get (C++17)	returns the calendar time in seconds and nanoseconds based on a given time base (function)
tm	calendar time type (class)
C documentation for timespec