bug#51321: 29.0.50; date in modelines

[Daniel Martín]

Eli Zaretskii <eliz@gnu.org> writes:

>
> I don't know what this means in terms of LC_* locale settings that
> Emacs sees.  can some macOS expert please chime in and help me
> understand where is the problem here?

It depends on how you start Emacs.  The common case on macOS is that
people start Emacs from the GUI, and in that case the OS doesn't
configure the locale environment variables.  What the NS port does is it
uses the OS API to get the locale and applies the environment variables
manually (see ns_init_locale in nsterm.m).

I see that ns_init_locale only sets LANG, which seems insufficient for
this use case.  Perhaps we need to extend ns_init_locale to set other
LC_ variables as well (LC_TIME is the key here).

A workaround for now without modifying Emacs (it may be useful for the
OP) is to evaluate the following ELisp form:

(setq system-time-locale "da_DK.UTF-8")

If I'm not mistaken, this would make display-local-time print Danish
dates when the date format is %c, %a, etc.