Skip site navigation (1) Skip section navigation (2)

Re: Setting timezone: is it bug or intended?

From: Bruce Momjian <bruce(at)momjian(dot)us>
To: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
Cc: Yura Sokolov <funny(dot)falcon(at)gmail(dot)com>, Susanne Ebrecht <susanne(at)2ndQuadrant(dot)com>, pgsql-bugs(at)postgresql(dot)org
Subject: Re: Setting timezone: is it bug or intended?
Date: 2011-09-07 02:08:16
Message-ID: 201109070208.p8728GK10336@momjian.us (view raw or flat)
Thread:
Lists: pgsql-bugs
Tom Lane wrote:
> Bruce Momjian <bruce(at)momjian(dot)us> writes:
> > Tom Lane wrote:
> >> It already is documented.  See
> >> http://developer.postgresql.org/pgdocs/postgres/datatype-datetime.html#DATATYPE-TIMEZONES
> >> specifically the point that POSIX zone names have the opposite sign
> >> convention from ISO-8601.
> >> 
> >> The great thing about standards is there are so many to choose from ;-)
> 
> > What isn't documented is why the sign changes for +0300 but not +03:
> 
> +03:00 is a legal POSIX zone name (hence the sign is different from SQL
> convention).  The other one is evidently being handled by this code path
> in check_timezone:
> 
> 		/*
> 		 * Try it as a numeric number of hours (possibly fractional).
> 		 */
> 		hours = strtod(*newval, &endptr);
> 		if (endptr != *newval && *endptr == '\0')
> 		{
> 			/* Here we change from SQL to Unix sign convention */
> 			myextra.CTimeZone = -hours * SECS_PER_HOUR;
> 			myextra.HasCTZSet = true;
> 		}
> 
> which I think is legacy code meant to deal with SQL-standard
> specification of timezone offsets as INTERVAL values.  You get the same
> interpretation of sign when you use the SQL-spec syntax:
> 
> regression=# set time zone interval '+03:00';
> SET
> regression=# select now();
>               now              
> -------------------------------
>  2011-04-27 00:44:53.560295+03
> (1 row)
> 
> Like I said, too many standards with their fingers in this pie.

I assume we decided we can't improve this.

-- 
  Bruce Momjian  <bruce(at)momjian(dot)us>        http://momjian.us
  EnterpriseDB                             http://enterprisedb.com

  + It's impossible for everything to be true. +

In response to

pgsql-bugs by date

Next:From: Bruce MomjianDate: 2011-09-07 02:54:39
Subject: Re: [BUGS] documentation bug - behave of NEW a OLD in plpgsql's triggers
Previous:From: Jack_WuDate: 2011-09-07 01:11:32
Subject: In Windows Server 2008 PostgreSQL8.3 service on Local Computer started and then stopped.

Privacy Policy | About PostgreSQL
Copyright © 1996-2014 The PostgreSQL Global Development Group