locale-info
locale-info is a built-in function in `C source code
'.
(locale-info ITEM)
Access locale data ITEM for the current C locale, if available.
ITEM should be one of the following:
`codeset', returning the character set as a string (locale item CODESET);
`days', returning a 7-element vector of day names (locale items DAY_n);
`months', returning a 12-element vector of month names (locale items MON_n);
`paper', returning a list (WIDTH HEIGHT) for the default paper size,
both measured in millimeters (locale items PAPER_WIDTH, PAPER_HEIGHT).
If the system can't provide such information through a call to
`nl_langinfo', or if ITEM isn't from the list above, return nil.
See also Info node `(libc)Locales'.
The data read from the system are decoded using `locale-coding-system'.