Re: [GENERAL] ISO week dates

Guillaume Lelarge wrote:
> I've tried to work on the first one, the ISO day field. My patch is
> attached and is against CVS HEAD. It only takes care of the code,
> nothing is done for documentation matter. It works with me :
>
> toto=# select to_char(('2006-10-'||a+2)::date, 'DAY') as "dow",
> to_char(('2006-10-'||a+2)::date, 'ID') as "ID field",
> to_char(('2006-10-'||a+2)::date, 'D') as "D field"
> from generate_series(1, 15) as a;

There is an inconsistency here: 'IYYY' is the four-digit ISO year, 'IW'
is the two-digit ISO week, but 'ID' would be the one-digit ISO
day-of-the-week. I'm not sure we can fix that, but I wanted to point
it out.

We should also support a format for ISO day-of-the-year, which might
be 'IDDD'.

--
Peter Eisentraut
http://developer.postgresql.org/~petere/