Re: Where are the legal values for LC_TIME listed?

[Bryn Llewellyn]

t...@sss.pgh.pa.us wrote:

> Bryn wrote:
> 
>> It’s easy to guess values for, say, countries in Europe:
> 
> On Unix-ish systems, "locale -a" should provide the set of available values.  
> We don't attempt to document this because it's so installation-dependent.
> 
>> But what do I use for, say, Simplified Chinese?
> 
> Maybe you don't have a suitable locale installed.
> 
>> The obvious search (LC_TIME in the search box of the PG doc for the current 
>> version) gets no useful hits.
> 
> The main entry for lc_time in
> 
> 19.11.2. Locale and Formatting: 
> https://www.postgresql.org/docs/current/runtime-config-client.html#RUNTIME-CONFIG-CLIENT-FORMAT
>  
> 
> says “Acceptable values are system-dependent; see Section 23.1 for more 
> information", and if you follow that link, you'll read
> 
>What locales are available on your system under what names depends on what 
> was provided by the operating system vendor and what was
>installed. On most Unix systems, the command `locale -a` will provide a 
> list of available locales.
> 
> Not sure what more we could say.

Thanks for the quick reply, Tom. `locale -a` showed that I do have a suitable 
locale installed. When I add an extra paragraph to my code that starts with 
`set lc_time = 'zh_CN’;`, I get this:

 星期一 / 九月
 一 03- 9-1042 12:00:00.543216 BC

What looks like an m-dash is actually the Chinese character for “one” as in 
“星期一” (lit. “week-one” which is the convention they adopted when they adopted 
the Western Calendar). Had I picked Friday (“星期五”) the output would have been 
nicer.

About “ Not sure what more we could say”, no… I don’t suppose there’s a 
cost-effective next step. In an ideal world, you’d have O/S-dependent code that 
reads the output of `locale -a`, sanitizes it to get the legal arguments for 
`set lc_time`, and presents it as a relation.

My problem is that doc search only gets me so far. Then I have to read each 
whole page from top to bottom to find the nuggets—in this case “ Acceptable 
values are system-dependent”.

Re: Where are the legal values for LC_TIME listed?

[Tom Lane]

Bryn Llewellyn  writes:
> It’s easy to guess values for, say, countries in Europe:

On Unix-ish systems, "locale -a" should provide the set of
available values.  We don't attempt to document this
because it's so installation-dependent.

> But what do I use for, say, Simplified Chinese?

Maybe you don't have a suitable locale installed.

> The obvious search (LC_TIME in the search box of the PG doc for the current 
> version) gets no useful hits.

The main entry for lc_time in

https://www.postgresql.org/docs/current/runtime-config-client.html#RUNTIME-CONFIG-CLIENT-FORMAT

says "Acceptable values are system-dependent; see Section 23.1 for more
information", and if you follow that link, you'll read

What locales are available on your system under what names depends on
what was provided by the operating system vendor and what was
installed. On most Unix systems, the command locale -a will provide a
list of available locales.

Not sure what more we could say.

regards, tom lane

Where are the legal values for LC_TIME listed?

[Bryn Llewellyn]

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 timestampnot 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- 
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=en=LC_TIME+site:https://www.postgresql.org/docs/13/=UTF-8=UTF-8