Debian Bug report logs - #149902
strftime("%Z") uses ambiguous timezone names

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Message #5 received at submit@bugs.debian.org (full text, mbox, reply):

From: Martijn van Oosterhout <kleptog@svana.org>

To: Debian Bug Tracking System <submit@bugs.debian.org>

Subject: date: does not understand some timezones

Date: Fri, 14 Jun 2002 00:45:22 +1000

Package: shellutils
Version: 2.0.11-11
Severity: normal


The timezones EST and CST are somewhat ambiguous. When using
Australia/Sydney, displaying the current time produces:

$ date
Fri Jun 14 00:36:08 EST 2002

It would be nicer if it displayed AEST and ACST for the australian
timezones. At the very least it should accept them for input.

$ date --date="Jun 14 00:36:08 AEST 2002"
date: invalid date `Jun 14 00:36:08 AEST 2002'

Or, put another way:

$ date +%Z
EST
$ date +%z
+1000
$ TZ=EST date +%Z
EST
$ TZ=EST date +%z
-0500


-- System Information
Debian Release: 3.0
Architecture: i386
Kernel: Linux vali 2.4.17 #3 Wed Feb 20 22:24:35 EST 2002 i686
Locale: LANG=C, LC_CTYPE=C

Versions of packages shellutils depends on:
ii  libc6                        2.2.5-5     GNU C Library: Shared libraries an
ii  login                        20000902-12 System login tools

Message #10 received at 149902@bugs.debian.org (full text, mbox, reply):

From: Thomas Hood <jdthood@yahoo.co.uk>

To: control@bugs.debian.org

Cc: 149902@bugs.debian.org, Martijn van Oosterhout <kleptog@svana.org>

Subject: wish

Date: 25 Sep 2002 17:11:44 +0200

severity 149902 wishlist
thanks

The following answer in the libc6 FAQ may be relevant:

------------------------------------------
The problem is that people still use the braindamaged POSIX method to
select the timezone using the TZ environment variable with a format EST5EDT
or whatever.  People, if you insist on using TZ instead of the timezone
database (see below), read the POSIX standard, the implemented behaviour is
correct!  What you see is in fact the result of the decisions made while
POSIX.1 was created.  We've only implemented the handling of TZ this way to
be POSIX compliant.  It is not really meant to be used.

The alternative approach to handle timezones which is implemented is the
correct one to use: use the timezone database.  This avoids all the problems
the POSIX method has plus it is much easier to use.  Simply run the tzselect
shell script, answer the question and use the name printed in the end by
making a symlink /etc/localtime pointing to /usr/share/zoneinfo/NAME (NAME
is the returned value from tzselect).  That's all.  You never again have to
worry.

So, please avoid sending bug reports about time related problems if you use
the POSIX method and you have not verified something is really broken by
reading the POSIX standards.

Message #17 received at 149902@bugs.debian.org (full text, mbox, reply):

From: Martijn van Oosterhout <kleptog@svana.org>

To: Thomas Hood <jdthood@yahoo.co.uk>

Cc: 149902@bugs.debian.org

Subject: Re: wish

Date: Thu, 26 Sep 2002 09:48:47 +1000

I think you misunderstood the report. I am not using the TZ variable at all
normally. What I was complaining about was that the output produced by date
did not reflect the timezone properly. It displays EST for Eastern
Australian which is ambiguous. The generally accepted form is AEST, as can
be seen at:

http://www.timeanddate.com/time/abbreviations.html
http://www.mhonarc.org/archive/html/mhonarc-users/1998-11/msg00093.html

Actually, it looks like somebody already submitted a bug for this (#93810)
with a patch against libc6. However, that won't fix date to actually accept
the form AEST.

And in relation to the FAQ entry:

On Wed, Sep 25, 2002 at 05:11:44PM +0200, Thomas Hood wrote:
> The following answer in the libc6 FAQ may be relevant:
> 
> ------------------------------------------
> The problem is that people still use the braindamaged POSIX method to
> select the timezone using the TZ environment variable with a format EST5EDT
> or whatever.  People, if you insist on using TZ instead of the timezone
> database (see below), read the POSIX standard, the implemented behaviour is
> correct!  What you see is in fact the result of the decisions made while
> POSIX.1 was created.  We've only implemented the handling of TZ this way to
> be POSIX compliant.  It is not really meant to be used.

That's all really nice, except how do you deal with multiple timezones on
the same machine used by different users? They can't all have /etc/localtime
pointing their way. Last I checked TZ='Australia/Sydney' didn't work.

Thanks,
-- 
Martijn van Oosterhout   <kleptog@svana.org>   http://svana.org/kleptog/
> There are 10 kinds of people in the world, those that can do binary
> arithmetic and those that can't.

Message #22 received at 149902@bugs.debian.org (full text, mbox, reply):

From: Michael Stone <mstone@debian.org>

To: Martijn van Oosterhout <kleptog@svana.org>, 149902@bugs.debian.org

Cc: Thomas Hood <jdthood@yahoo.co.uk>

Subject: Re: Bug#149902: wish

Date: Wed, 25 Sep 2002 20:10:08 -0400

>On Wed, Sep 25, 2002 at 05:11:44PM +0200, Thomas Hood wrote:
>That's all really nice, except how do you deal with multiple timezones on
>the same machine used by different users? They can't all have /etc/localtime
>pointing their way. Last I checked TZ='Australia/Sydney' didn't work.

e.g.: 
TZ=Australia/Queensland
TZ=Australia/NSW
TZ=Australia/Victoria

Mike Stone

Message #27 received at 149902@bugs.debian.org (full text, mbox, reply):

From: Martijn van Oosterhout <kleptog@svana.org>

To: Michael Stone <mstone@debian.org>

Cc: 149902@bugs.debian.org, Thomas Hood <jdthood@yahoo.co.uk>

Subject: Re: Bug#149902: wish

Date: Thu, 26 Sep 2002 10:15:54 +1000

On Wed, Sep 25, 2002 at 08:10:08PM -0400, Michael Stone wrote:
> >On Wed, Sep 25, 2002 at 05:11:44PM +0200, Thomas Hood wrote:
> >That's all really nice, except how do you deal with multiple timezones on
> >the same machine used by different users? They can't all have 
> >/etc/localtime
> >pointing their way. Last I checked TZ='Australia/Sydney' didn't work.
> 
> e.g.: 
> TZ=Australia/Queensland
> TZ=Australia/NSW
> TZ=Australia/Victoria

Ok, I stand corrected. It doesn't change the fact that the output it
ambiguous:

$ TZ=Australia/Sydney date
Thu Sep 26 10:13:10 EST 2002

EST?
-- 
Martijn van Oosterhout   <kleptog@svana.org>   http://svana.org/kleptog/
> There are 10 kinds of people in the world, those that can do binary
> arithmetic and those that can't.

Message #32 received at 149902@bugs.debian.org (full text, mbox, reply):

From: Michael Stone <mstone@debian.org>

To: Martijn van Oosterhout <kleptog@svana.org>

Cc: 149902@bugs.debian.org, Thomas Hood <jdthood@yahoo.co.uk>

Subject: Re: Bug#149902: wish

Date: Wed, 25 Sep 2002 21:32:45 -0400

reassign 149902 libc6
quit

On Thu, Sep 26, 2002 at 10:15:54AM +1000, Martijn van Oosterhout wrote:
>Ok, I stand corrected. It doesn't change the fact that the output it
>ambiguous:
>
>$ TZ=Australia/Sydney date
>Thu Sep 26 10:13:10 EST 2002
>
>EST?

That doesn't come from date:

> env TZ=Australia/NSW perl -e 'use POSIX 'strftime'; print strftime "%c\n", localtime;'
Thu 26 Sep 2002 11:31:55 AM EST

Mike Stone

Message #37 received at 149902-submitter@bugs.debian.org (full text, mbox, reply):

From: Jeff Bailey <jbailey@nisa.net>

To: 149902@bugs.debian.org

Cc: 149902-submitter@bugs.debian.org

Subject: Australian time zones

Date: Sun, 21 Dec 2003 00:39:44 -0500

[Message part 1 (text/plain, inline)]

http://www.timeanddate.com/library/abbreviations/timezones/au/

Shows that 'EST' is in fact the most correct abbreviation for date to
return.

I'm tagging this bug as 'wontfix'.

-- 
In the United States, there isn't a government database that hasn't been
misused by the very people entrusted with keeping its information safe.
 - Bruce Schneier

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Message #51 received at 149902@bugs.debian.org (full text, mbox, reply):

From: <Tyson.Clugg@csiro.au>

To: <149902@bugs.debian.org>

Cc: <149902-submitter@bugs.debian.org>, <jbailey@nisa.net>, <mstone@debian.org>

Subject: Australian time zones

Date: Fri, 9 Dec 2005 16:43:48 +1100

The official list of timezones for Australia, as provided by the Australian Government, does not include EST anywhere on the page.  AEST is the correct abbreviation.

<quote url="http://www.australia.gov.au/about-australia-13time">

There are three times zones in Australia -

    * Australian Eastern Standard Time (AEST): Greenwich Mean Time (GMT) plus 10 hours for standard time and 11 hours for daylight savings time. AEST is followed in these regions:
          o New South Wales
          o Victoria
          o Queensland
          o Tasmania
          o Australian Capital Territory

    * Australian Central Standard Time (ACST): GMT plus 9 ½ hours for standard time and 10 ½ hours for daylight savings time. ACST is followed in these regions:
          o South Australia
          o Northern Territory

    * Australian Western Standard Time (AWST): GMT plus 8 hours. AWST is followed in these regions:
          o Western Australia

</quote>

This should be re-opened as a bug.  Timeanddate.com do not have the most correct timezone information on their website, the Australian Government do.

Regards,
Tyson Clugg.

Message #59 received at 149902@bugs.debian.org (full text, mbox, reply):

From: GOTO Masanori <gotom@sanori.org>

To: <Tyson.Clugg@csiro.au>, 149902@bugs.debian.org

Cc: <149902-submitter@bugs.debian.org>, <jbailey@nisa.net>, <mstone@debian.org>

Subject: Re: Bug#149902: Australian time zones

Date: Tue, 20 Dec 2005 09:47:56 +0900

At Fri, 9 Dec 2005 16:43:48 +1100,
<Tyson.Clugg@csiro.au> wrote:
> The official list of timezones for Australia, as provided by the Australian Government, does not include EST anywhere on the page.  AEST is the correct abbreviation.
> 
> <quote url="http://www.australia.gov.au/about-australia-13time">
> 
> There are three times zones in Australia -
> 
>     * Australian Eastern Standard Time (AEST): Greenwich Mean Time (GMT) plus 10 hours for standard time and 11 hours for daylight savings time. AEST is followed in these regions:
>           o New South Wales
>           o Victoria
>           o Queensland
>           o Tasmania
>           o Australian Capital Territory
> 
>     * Australian Central Standard Time (ACST): GMT plus 9 ½ hours for standard time and 10 ½ hours for daylight savings time. ACST is followed in these regions:
>           o South Australia
>           o Northern Territory
> 
>     * Australian Western Standard Time (AWST): GMT plus 8 hours. AWST is followed in these regions:
>           o Western Australia
> 
> </quote>
> 
> This should be re-opened as a bug.  Timeanddate.com do not have the most correct timezone information on their website, the Australian Government do.

Note that you probably want to know why AEST vs EST is long-standing
problem: the short summary is available in glibc source tree
timezone/australasia.  Not only one governmental page but also showing
another information source would be nice idea to change time zone
maintainers.

-- gotom

Message #67 received at 149902@bugs.debian.org (full text, mbox, reply):

From: Martijn van Oosterhout <kleptog@svana.org>

To: GOTO Masanori <gotom@sanori.org>, 149902-quiet@bugs.debian.org

Cc: Tyson.Clugg@csiro.au, 149902@bugs.debian.org, 149902-submitter@bugs.debian.org, jbailey@nisa.net, mstone@debian.org

Subject: Re: Bug#149902: Australian time zones

Date: Tue, 20 Dec 2005 08:26:29 +0100

[Message part 1 (text/plain, inline)]

On Tue, Dec 20, 2005 at 09:47:56AM +0900, GOTO Masanori wrote:
> Note that you probably want to know why AEST vs EST is long-standing
> problem: the short summary is available in glibc source tree
> timezone/australasia.  Not only one governmental page but also showing
> another information source would be nice idea to change time zone
> maintainers.

Wow, this is a bug come back from the dead. I read the summary in glibc
and think it's wierd. For example, the counts supposedly showing
"Eastern Standard Time" to be more popular than "Australia Eastern
Standard Time" are bogus. The first search is obviously going to
include the results of the second. A simple calculation shows that even
then the prefix was four times as common as without.

Current figures from Google:
"Australian Eastern Standard Time" site:.au     155000
"Eastern Standard Time" site:.au                206000
"Eastern Standard Time" -"Australian Eastern Standard Time" site:.au  50000

But in my mind the argument is simple: EST is ambiguous, AEST is not.
The issue I had has to do with input, not output. Saying "9:00 EST"
is ambiguous, but "9:00 AEST" is not even recognised as a valid date.
Obviously you can't remove all ambiguity, but it's certainly worth
removing whenever possible.

There is still no way to specify an Australian timezone to date, which
I suppose is the real bug. Yes, you can affect it with environment
variables, but still...

$ date --date='9:00 Australia/Sydney'
date: invalid date `9:00 Australia/Sydney'
$ date --date='9:00 EST'
Tue Dec 20 15:00:00 CET 2005     <--- ??? Not european time. What is it?
$ date --date='9:00 AEST'
date: invalid date `9:00 AEST'

Have a nice day,
-- 
Martijn van Oosterhout   <kleptog@svana.org>   http://svana.org/kleptog/
> Patent. n. Genius is 5% inspiration and 95% perspiration. A patent is a
> tool for doing 5% of the work and then sitting around waiting for someone
> else to do the other 95% so you can sue them.

[Message part 2 (application/pgp-signature, inline)]

Message #80 received at 149902@bugs.debian.org (full text, mbox, reply):

From: GOTO Masanori <gotom@sanori.org>

To: Martijn van Oosterhout <kleptog@svana.org>

Cc: GOTO Masanori <gotom@sanori.org>, 149902-quiet@bugs.debian.org, Tyson.Clugg@csiro.au, 149902@bugs.debian.org, 149902-submitter@bugs.debian.org, jbailey@nisa.net, mstone@debian.org

Subject: Re: Bug#149902: Australian time zones

Date: Sun, 01 Jan 2006 15:49:23 +0900

At Tue, 20 Dec 2005 08:26:29 +0100,
Martijn van Oosterhout wrote:
> Wow, this is a bug come back from the dead. I read the summary in glibc
> and think it's wierd. For example, the counts supposedly showing
> "Eastern Standard Time" to be more popular than "Australia Eastern
> Standard Time" are bogus. The first search is obviously going to
> include the results of the second. A simple calculation shows that even
> then the prefix was four times as common as without.
> 
> Current figures from Google:
> "Australian Eastern Standard Time" site:.au     155000
> "Eastern Standard Time" site:.au                206000
> "Eastern Standard Time" -"Australian Eastern Standard Time" site:.au  50000

This information is probably useful to change upstream timezone
maintainer's mind.  Do you have actual information of the goverment
statements?  If Australian goverment decided to encourage using AEST
instead of EST, it's also useful.  If you have one, we should transfer
your information to upstream.

> But in my mind the argument is simple: EST is ambiguous, AEST is not.
> The issue I had has to do with input, not output. Saying "9:00 EST"
> is ambiguous, but "9:00 AEST" is not even recognised as a valid date.
> Obviously you can't remove all ambiguity, but it's certainly worth
> removing whenever possible.
>
> There is still no way to specify an Australian timezone to date, which
> I suppose is the real bug. Yes, you can affect it with environment
> variables, but still...
> 
> $ date --date='9:00 Australia/Sydney'
> date: invalid date `9:00 Australia/Sydney'
> $ date --date='9:00 EST'
> Tue Dec 20 15:00:00 CET 2005     <--- ??? Not european time. What is it?
> $ date --date='9:00 AEST'
> date: invalid date `9:00 AEST'

Actually upstream author also considered this ambiguity, and they
finally decided short abbreviated timezone could be conflicted each
other - for example they explained "IST" in their arguments (did you
see australasia file?).

-- gotom

Message #105 received at 149902@bugs.debian.org (full text, mbox, reply):

From: Timothy Arceri <t_arceri@yahoo.com.au>

To: 149902@bugs.debian.org

Subject: Fixed upstream

Date: Thu, 03 Jul 2014 07:27:49 +1000

This has finally been fixed upstream (yay). This bug can be closed.

http://mm.icann.org/pipermail/tz/2014-June/021089.html

Message #106 received at 95254-done@bugs.debian.org (full text, mbox, reply):

From: Paul Eggert <eggert@cs.ucla.edu>

To: 95254-done@bugs.debian.org

Subject: Re: strftime("%Z") uses ambiguous timezone names

Date: Tue, 12 Aug 2014 00:52:58 -0700

As this bug is fixed in Debian sid now, I'm marking it as done.

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