[DatePicker] October turns into September for some years when localized

[amangeot]

Hello,
There is a funny issue with some dates in DatePicker component when it is localized. Some years display "October" as "September" around 1990.

You can see it on the demo, going for the localized examples, with "fr locale" for example. Select year 1990, and go for September, then October:
http://www.material-ui.com/#/components/date-picker

Tested on Windows 10, Chrome

[mbrookes]

I can't reproduce, but I'm in the UK, so wondering if its (also?) related to this #7070 ? I know we have other open issues for similar problems. I couldn't find the one I was looking for.

DatePicker & TimePicker need an overhaul for next, but they're big hairy components, so no-one has tried to tackle them yet...

[MathieuCh]

An user of our platform just reported this issue with fr as locale language, In 1995 the month of october is named september. (Tested on Windows 8.1, Chrome)

Weird issue 👍

[franciscocpg]

Same for me

pt-BR locale

fr locale

en locale

It doesn't make any sense that days are "changing" because of locale. After all, it's the same gregorian calendar, right?

[NonameSLdev]

Huh. I'm getting even odder behaviour:

(If you missed the point: July, August, August, September, November)

[oliviertassinari]

Closing for #4787