The test is unstable and it's not really interesting to test exactly how
threads are handled.

the DST transition.  Patch by Joe Peterson.

the DST transition.  Patch by Joe Peterson.

Thanks to Eric Snow for the patch.

time.process_time() is CPU time, not a number of seconds.

Issue #14521: Make result of float('nan') and float('-nan') more consistent across platforms.  Further, don't rely on Py_HUGE_VAL for float('inf').