[clug] timezone amusements.

Francis James Whittle fudje at grapevine.net.au
Fri Mar 6 23:46:23 GMT 2009



EST is obsolete! (AEST and AEDT too, which are also wrong)

(On a related 2004 called, they want their PostgreSQL 7 back!  Why oh
why does everyone insist on still using 7.4?  WHY?!  Additionally PHP4
called, it wants its gpc_magic_quotes back.)

Any back on topic, the abbreviation doesn't matter so much (and
historically should display EST whether it has daylight saving or not,
which is confusing for Queenslanders anyway), because a couple of years
ago the timezone naming convention went for an Area/Zone string instead
of abbreviations which (a) have conflicts (admittedly it was just EST,
IIRC because eastern America changed from ET to EST which eastern
Australia already had), and (b) don't contain all the information (such
as daylight savings time specifics.  Eg. EST applies to Queensland as
well, but refers to a technically different time zone for almost half
the year, but Australia/Brisbane and Australia/Sydney continue to be

Of course if you're using PostgreSQL 7 your timezone information may be
old and useless anyway (WHY?!  WHYYYYYYYYYYYYYYY must they use the old


On Thu, 2009-03-05 at 21:59 +1100, Tomasz Ciolek wrote:
> Hi All
> It has recently come to my attention that timezone data that ships with Debian
> and Ubuntu suffers from some (major, in my option) problems with time
> zone naming abbreviations that are displayed by 'date' command and coded
> into /etc/localtime. here is a summary of what I am seeing:
> 1. What seems to be happenign is that the debain tzdata package (which is
> downstream build from gnu libc6 source) uses EST and EDT instead of AEST and
> AEDT to designate Australian Eastern Standard time and Australian
> Eastern Daylight Time.
> 2. Timezone defintions, when queries like this: 
> zdump -c 2009 -v Australia/Sydney|grep 2008
> produce this time zone defintion for standard time to daylight time
> change over dates:
> Australia/Sydney  Sat Apr  5 15:59:59 2008 UTC = Sun Apr  6 02:59:59
> 2008 EST isdst=1 gmtoff=39600
> Australia/Sydney  Sat Apr  5 16:00:00 2008 UTC = Sun Apr  6 02:00:00
> 2008 EST isdst=0 gmtoff=36000
> Australia/Sydney  Sat Oct  4 15:59:59 2008 UTC = Sun Oct  5 01:59:59
> 2008 EST isdst=0 gmtoff=36000
> Australia/Sydney  Sat Oct  4 16:00:00 2008 UTC = Sun Oct  5 03:00:00
> 2008 EST isdst=1 gmtoff=39600
> again this uses EST instead of AEST and there is no EDT or AEDT at all.
> As far as I can tell this this is the relevant source of truth about
> what Autsralian timezones are called : http://www.australia.gov.au/Time
> What I am interested to find out:
> 1. is this is a debian and Ubuntu specific issue or a wider libc6 issue 
> that is present in all Linux distributions (Gentoo, RH, Fedora, CentOS, etc)
> 2. if this is a libc6 issue, how do we get it fixed?
> Why do I care: because there is a number of web application engines that
> automatically set timezeone of the instance based on system timezone,
> and I ams sick of trying to convince the applicatios that I am not in the 
> Eastern USA...
> regards
> Tomasz Ciolek

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