On Mon, 3 Jul 2023 at 17:13, Matthias van de Meent < boekewurm+postg...@gmail.com> wrote:
> On Mon, 3 Jul 2023 at 20:06, Dave Cramer <davecra...@gmail.com> wrote: > > > > Greetings, > > > > For ISO and German dates the order DMY is completely ignored on output > but used for input. > > > > test=# set datestyle to 'ISO,DMY'; > > SET > > select '7-8-2023'::date > > test-# ; > > date > > ------------ > > 2023-08-07 > > (1 row) > > > > test=# set datestyle to 'ISO,MDY'; > > SET > > test=# select '7-8-2023'::date > > ; > > date > > ------------ > > 2023-07-08 > > (1 row) > > > > Note regardless of how the ordering is specified it is always output as > > YMD > > Wouldn't that be because ISO only has one correct ordering of the day > and month fields? I fail to see why we'd output non-ISO-formatted date > strings when ISO format is requested. I believe the reason is the same > for German dates - Germany's official (or most common?) date > formatting has a single ordering of these fields, which is also the > ordering that we supply. > seems rather un-intuitive that it works for some datestyles and not for others > > The code comments also seem to hint to this: > > > case USE_ISO_DATES: > > case USE_XSD_DATES: > > /* compatible with ISO date formats */ > > > case USE_GERMAN_DATES: > > /* German-style date format */ > > This has been this way since the code for ISO was originally committed > in July of '97 with 8507ddb9 and the GERMAN formatting which was added > in December of '97 as D.M/Y with 352b3687 (and later that month was > updated to D.M.Y with ca23837a). > Sadly, the -hackers archives don't seem to have any mails from that > time period, so I couldn't find much info on the precise rationale > around this behavior. > Yeah, I couldn't find much either. > > Kind regards, > > Matthias van de Meent > Neon (https://neon.tech/) > > PS. That was some interesting digging into the history of the date > formatting module. > Always interesting digging into the history of the project. Dave
