26.0.91. Haven't built it totally clean yet, will try that way if no one else can dupe. Maybe there's a stale variable in my build process somewhere, but I thought being able to toggle the but with scope types was a signal against that possibility.

On Mon, Mar 5, 2018, 21:39 Eli Zaretskii <eliz@gnu.org> wrote:
> From: Jacob MacDonald <jaccarmac@gmail.com>
> Date: Tue, 06 Mar 2018 00:46:22 +0000
>
> To reproduce: On a Windows version of Emacs:
>
> Evaluate (parse-time-string "2018-03-05")
>
> A list of all nils is returned.

In what version of Emacs do you see this?  I cannot reproduce neither
in the current emacs-26 branch nor on master.