Where are the legal values for LC_TIME listed?

It’s easy to guess values for, say, countries in Europe:

This:

create function to_char_demo()
returns table(z text)
language plpgsql
as $body$
declare
-- Counted from midnight 1-Jan-1970 UTC.
secs constant double precision not null := 94996756799.456789;
t constant timestamp not null := to_timestamp(-secs) at time zone 'UTC';
fmt_1 constant text not null := 'TMDay / TMMonth';
fmt_2 constant text not null := 'TMDy dd-TMMon-yyyy hh24:mi:ss.us BC';
begin
set lc_time = 'en_US';
z := to_char(t, fmt_1); return next;
z := to_char(t, fmt_2); return next;
z := ''; return next;

set lc_time = 'it_IT';
z := to_char(t, fmt_1); return next;
z := to_char(t, fmt_2); return next;
z := ''; return next;

set lc_time = 'fi_FI';
z := to_char(t, fmt_1); return next;
z := to_char(t, fmt_2); return next;
end;
$body$;

select z from to_char_demo();

…brings this result:

Monday / September
Mon 03-Sep-1042 12:00:00.543216 BC

Lunedì / Settembre
Lun 03-Set-1042 12:00:00.543216 BC

Maanantai / Syyskuu
Ma 03-Syy-1042 12:00:00.543216 BC

But what do I use for, say, Simplified Chinese? Nothing that I guess works. And, unlike is the case with “set IntervalStyle”, a bad value doesn’t bring a hint (or a doc ref) that gives the LoV.

The obvious search (LC_TIME in the search box of the PG doc for the current version) gets no useful hits. Nor does this:

https://www.google.com/search?client=safari&rls=en&q=LC_TIME+site:https://www.postgresql.org/docs/13/&ie=UTF-8&oe=UTF-8 <https://www.google.com/search?client=safari&rls=en&q=LC_TIME+site:https://www.postgresql.org/docs/13/&ie=UTF-8&oe=UTF-8>