Hello,
We have checked again and noticed the month, day, etc in the language settings are for the display date on the page, and not for the graph. By default, the date locale in the graph will try to use the locale date in the browser setting.
Currently, most of the language variables for the public page are translateable, except for the Admin CP. Some wording in the Admin CP is directly written in the code to reduce language variable size.
Regards,