Not only date/datetime/time fields are broken. Also type=number does not work consistently across different locales and different browsers. Some don't let you type decimal comma.
Now, I also happen to be working on refactor of our Intl code, so I should be able to help with the number field being inconsistent. If you can file a bug and prepare a minimized testcase, I'd be happy to fix it! :)
[0] https://bugzilla.mozilla.org/show_bug.cgi?id=888320 [1] https://bugzilla.mozilla.org/show_bug.cgi?id=1069609
Id est: use max="100000". Then on one IE/Edge 16000 is an error but 15000 is OK. Different IE/Edge box its 18000 cap.
I have to make a custom UI component to make this work (riotjs)