I got a few failures on my Windows machine running `PCbuild\python_d.exe -m test -j0 -rW` [1], only one of which looks relevant [2]:

======================================================================
FAIL: test_monotonic (test.test_time.TimeTestCase)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "P:\Projects\OSS\Python\hg.python.org\default\cpython\lib\test\test_time.
py", line 397, in test_monotonic
    support.check_time_delta(0.5, dt, 0.5, clock='monotonic')
  File "P:\Projects\OSS\Python\hg.python.org\default\cpython\lib\test\support\__
init__.py", line 2241, in check_time_delta
    message))
AssertionError: timing 608.0 ms seconds > max timing 500.0 ms seconds; the clock
 'monotonic' has a resolution of 15.6 ms; tolerate 1.0 ms seconds

----------------------------------------------------------------------
Ran 45 tests in 1.869s

FAILED (failures=1, skipped=12)
test test_time failed

It may be interesting to also run this on a couple of the Windows buildbot 'custom' builders, particularly the XP bot (which has an odd resolution for time.monotonic) and the x86 Server 2003 bot (which is notoriously slow).

[1] excluding test_urllib2_localnet and test_asyncio, test_urllib2_localnet doesn't play nice with my network and test_asyncio had an output-eating failure on a previous attempt
[2] the other failures were test_os, test_ssl, and test_socket.  I believe their failures to be issues with my machine.