Ask HN: Is there a library implemnting Markus Kuhn's time.h?

Markus Kuhn's proposed improvements to <time.h> looks nice,[1] but the many timebases were not really added to C11. I wonder if anyone has made a library implmenting the interface (even just the timespec/xtime part)?

  [1]: https://news.ycombinator.com/item?id=8410220

The timespec/xtime part seems to map nicely to clock_gettime() + libtai, but I would really like to see something that makes it available on Windows too.