411 REFERENCE · Wikibooks
C++ Language/Std/CRuntime/Time/PreciseTime
Reference material by Wikibooks contributors. This retains its source identity and is not 411 news reporting.
The current time obtained by std::time() is appropriate for uses like the timestamp of a file.
But for a more precise measurement of time, set a std::chrono::time_point<std::chrono::high_resolution_clock> object to the value returned by std::chrono::high_resolution_clock::now().
Additional information about precisely measuring time (includes interactive examples)