Date format not adapting to language/region

[Altonss]

The date and time format is here not adapted to my locale (french).

On the side bar, the month is not translated: Can this string be localised?

[Altonss]

I found some string on weblate, but I don't know how to translate, it says there is an error... https://weblate.skyjake.fi/translate/lagrange/ui/fr/?q=has%3Adismissed-check&offset=2

[skyjake]

I found some string on weblate

That one is unrelated to these. At least the first one looks like it needs a new string added to the .po files.

[Altonss]

That one is unrelated to these.

Yes it is unrelated, I just mentioned it because it is related to date format and I wanted to debug it xD