BUG: remove millisecond field that raises valueerror
This would appear in the `dir` and cause tab completion to a field that would raise a `ValueError`. When I brought this up in gitter it seemed like it was safe to remove it.

I couldn't find any tests that hit this descriptor.

yeh, I think this was historicaly left in. can you add a test (assert that it raises), so when someone tries to add it back it will fail!. ping on green.
 Added the test, build is now passing
 thanks!
