std::timespec (3) Linux Manual Page

std::timespec – std::timespec

Synopsis

Defined in header <ctime>
struct timespec; (since C++17)
Structure holding an interval broken down into seconds and nanoseconds.

Member objects

std::time_t tv_sec whole seconds – >= 0
long tv_nsec nanoseconds – [0, 999999999]

See also

timespec_get returns the calendar time based on a given time base
              (function)
(since C++17)
              calendar time type
tm (class)