Defined in header <ctime>
int timespec_get( std::timespec* ts, int base)
(since C++17)
#define TIME_UTC /* implementation-defined */
(since C++17)
1) Modifies the std::timespec object pointed to by ts to hold the current calendar time in the time base base.
2) Expands to a value suitable for use as the base argument of std::timespec_get

Other macro constants beginning with TIME_ may be provided by the implementation to indicate additional time bases.

If base is TIME_UTC, then.

  • ts->tv_sec is set to the number of seconds since an implementation defined epoch, truncated to a whole value
  • ts->tv_nsec member is set to the integral number of nanoseconds, rounded to the resolution of the system clock


ts - pointer to an object of type std::timespec
base - TIME_UTC or another nonzero integer value indicating the time base

Return value

The value of base if successful, zero otherwise.


The POSIX function clock_gettime(CLOCK_REALTIME, ts) may also be used to populate a std::timespec with the time since the Epoch.


#include <cstdio>
#include <ctime>
int main()
    std::timespec ts;
    std::timespec_get(&ts, TIME_UTC);
    char buff[100];
    std::strftime(buff, sizeof buff, "%D %T", std::gmtime(&ts.tv_sec));
    std::printf("Current time: %s.%09ld UTC\n", buff, ts.tv_nsec);

Possible output:

Current time: 06/24/16 20:07:42.949494132 UTC

See also

(since C++17)
time in seconds and nanoseconds
returns the current time of the system as time since epoch

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