It returns 1551766256847 (so the same as https://www.epochconverter.com/, i.e. "Unix Time"), there's no reason to assume it returns something else with VS2019 (AFAICS), until/unless it supports C++20 and the std explicitly changes the behavior  (forces MS to break backward compatibility), you can be assured that it will be doing that for a while (until the Y38 problem raises its head).

degski