Re: [HACKERS] Problem with copying abstimes - Mailing list pgsql-hackers

From Ross Johnson
Subject Re: [HACKERS] Problem with copying abstimes
Date
Msg-id 8bec4c379f6bb867bbe6ee7388a6949d
Whole thread Raw
In response to [HACKERS] Problem with copying abstimes  (Ronald Baljeu <rjb@xs4all.nl>)
List pgsql-hackers
On Sat, 21 Jun 1997, Thomas G. Lockhart wrote:

> Bruce Momjian wrote:
> > Woh, I am sorry to jump in here, but we have to go by whatever Unix
> > gives us as a timezone.  If Unix can't get it right, I don't think
> > postgreSQL should be messing with it.
> >
> > Or am I missing something here.  Are there timezones hard-coded into
> > PostgreSQL?
>
> Well, the good news is that Unix gets it as right as anyone, and the bad
> news is that it isn't so good :/
>
> As far as I know, there is no defined interface to get access to
> non-default timezone information on Unix platforms (anyone having more
> info is welcome to steer us to the right place). Postgres has a fairly
> large table of timezone information (predating my involvement with it)
> which is used to parse input time strings, and which can be used for
> formatting output time strings for non-default time zones.

The only true representation for timezones is as an offset from UTC, as
used in email headers these days, at least those generated by sendmail.
The problem is that people are more familiar with acronyms even though
offsets are probably easier to use and to remember.

I see at least three problems with acronyms:-

1) they aren't standard internationally,

2) they aren't very informative when seen outside of the zone, country or
continent they apply to. (I could only guess at most of the zone strings
used in my own country.)

3) different acronyms are used for the same zone offset as you travel
north-south around the globe.

As PostgreSQL is used all over the Internet, would it be too radical to
suggest that PostgreSQL drop acronyms in favour of offsets as the default
when displaying or parsing timezones, and especially when copying in and
out?  Perhaps a modifiable system table could provide correspondence
between offsets and acronyms for those who want or need to use acronyms.

+----------------------+---+
| Ross Johnson         |   | E-Mail: rpj@ise.canberra.edu.au
| Info Sciences and Eng|___|
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| PO Box 1                 |
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