GNU bug report logs - #10455
Date: Possible bug in ISO-8601 formatted dates

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Message #5 received at submit <at> debbugs.gnu.org (full text, mbox):

From: Dotan Cohen <dotancohen <at> gmail.com>
To: bug-coreutils <at> gnu.org
Subject: Date: Possible bug in ISO-8601 formatted dates
Date: Sun, 8 Jan 2012 19:22:09 +0200

It seems that ISO-8601 formated dates are not properly handled by the
date utility. The date utility seems to erroneously add
timezone-shifting when using ISO-8601 dates. This example is fine (see
the date roundtrip to back where it started):
✈saturn:~$ date +%s -d "2006-12-31 22:00"
1167595200
✈saturn:~$ date -d @1167595200
Sun Dec 31 22:00:00 IST 2006

However, adding a "t" between the date and hour (as per ISO 8601)
breaks the roundtrip (the timestamp is wrong):
✈saturn:~$ date +%s -d "2006-12-31t22:00"
1167577200
✈saturn:~$ date -d @1167577200
Sun Dec 31 17:00:00 IST 2006

This is on a love-to-hate Debian-based distro, with GNU coreutils 8.5.
I can confirm the issue on CentOS with date 5.97. Without the "t" the
timestamp is correct:
[root <at> gs beer]# date +%s -d "2006-12-31 22:00"
1167602400
[root <at> gs beer]# date -d @1167602400
Sun Dec 31 22:00:00 UTC 2006

And with it, the timestamp is wrong.
[root <at> gs beer]# date +%s -d "2006-12-31t22:00"
1167577200
[root <at> gs beer]# date -d @1167577200
Sun Dec 31 15:00:00 UTC 2006

Note that IST (from the first server) is UTC+2.


-- 
Dotan Cohen

http://gibberish.co.il
http://what-is-what.com

Message #8 received at 10455 <at> debbugs.gnu.org (full text, mbox):

From: Bob Proulx <bob <at> proulx.com>
To: Dotan Cohen <dotancohen <at> gmail.com>
Cc: 10455 <at> debbugs.gnu.org
Subject: Re: bug#10455: Date: Possible bug in ISO-8601 formatted dates
Date: Sun, 8 Jan 2012 23:49:27 -0700

Dotan Cohen wrote:
> It seems that ISO-8601 formated dates are not properly handled by the
> date utility.

GNU date didn't learn how to handle ISO-8601 until very recently.
Your version 8.5 doesn't have that code yet.  Here is the NEWS file
entry for the change as it went into the recent 8.13 release.

* Noteworthy changes in release 8.13 (2011-09-08) [stable]

** New features

  date now accepts ISO 8601 date-time strings with "T" as the
  separator.  It has long parsed dates like "2004-02-29 16:21:42"
  with a space between the date and time strings.  Now it also parses
  "2004-02-29T16:21:42" and fractional-second and time-zone-annotated
  variants like "2004-02-29T16:21:42.333-07:00"

And here is the ChangeLog entry:

        date: support parsing of ISO-8601-with-"T" dates
        Thanks to an improvement in gnulib's parse-datetime module,
        commands like this now succeed (output manually indented):
            $ ./date -u -d 2004-02-29T16:21:42.33+07:00 +%FT%T.%N%z
                           2004-02-29T09:21:42.330000000+0000
        * tests/misc/date: Add a test to exercise the new-in-gnulib
        parsing of ISO8601-with-"T" dates.
        * NEWS (New features): Mention it.
        * gnulib: Update, to pull in this parse-datetime improvement.

Bob

Message #11 received at 10455 <at> debbugs.gnu.org (full text, mbox):

From: Dotan Cohen <dotancohen <at> gmail.com>
To: Bob Proulx <bob <at> proulx.com>
Cc: 10455 <at> debbugs.gnu.org
Subject: Re: bug#10455: Date: Possible bug in ISO-8601 formatted dates
Date: Mon, 9 Jan 2012 10:46:30 +0200

On Mon, Jan 9, 2012 at 08:49, Bob Proulx <bob <at> proulx.com> wrote:
> GNU date didn't learn how to handle ISO-8601 until very recently.
> Your version 8.5 doesn't have that code yet.  Here is the NEWS file
> entry for the change as it went into the recent 8.13 release.
>

Thanks, Bob. Have a great week!



-- 
Dotan Cohen

http://gibberish.co.il
http://what-is-what.com

Message #16 received at 10455-done <at> debbugs.gnu.org (full text, mbox):

From: Bob Proulx <bob <at> proulx.com>
To: Dotan Cohen <dotancohen <at> gmail.com>
Cc: 10455-done <at> debbugs.gnu.org
Subject: Re: bug#10455: Date: Possible bug in ISO-8601 formatted dates
Date: Mon, 9 Jan 2012 10:12:42 -0700

Dotan Cohen wrote:
> Bob Proulx wrote:
> > GNU date didn't learn how to handle ISO-8601 until very recently.
> > Your version 8.5 doesn't have that code yet.  Here is the NEWS file
> > entry for the change as it went into the recent 8.13 release.
> 
> Thanks, Bob. Have a great week!

Good.  I am going to close the bug report ticket with this message
then.

Bob

Message #17 received at 10455-done <at> debbugs.gnu.org (full text, mbox):

From: Dotan Cohen <dotancohen <at> gmail.com>
To: Bob Proulx <bob <at> proulx.com>
Cc: 10455-done <at> debbugs.gnu.org
Subject: Re: bug#10455: Date: Possible bug in ISO-8601 formatted dates
Date: Tue, 10 Jan 2012 03:23:55 +0200

On Mon, Jan 9, 2012 at 19:12, Bob Proulx <bob <at> proulx.com> wrote:
> Good.  I am going to close the bug report ticket with this message
> then.
>

No problem. I cannot test the later versions on any hardware I have
lying around, so when I see my distro up to 8.13 I'll double check. If
you would like me to confirm now do you have a system with a recent
GNU Tools that I could SSH into?


-- 
Dotan Cohen

http://gibberish.co.il
http://what-is-what.com

Message #20 received at 10455 <at> debbugs.gnu.org (full text, mbox):

From: Bob Proulx <bob <at> proulx.com>
To: Dotan Cohen <dotancohen <at> gmail.com>
Cc: 10455 <at> debbugs.gnu.org
Subject: Re: bug#10455: Date: Possible bug in ISO-8601 formatted dates
Date: Mon, 9 Jan 2012 22:12:49 -0700

Hi Dotan,

Dotan Cohen wrote:
> Bob Proulx wrote:
> > Good.  I am going to close the bug report ticket with this message
> > then.
> 
> No problem. I cannot test the later versions on any hardware I have
> lying around, so when I see my distro up to 8.13 I'll double check. If
> you would like me to confirm now do you have a system with a recent
> GNU Tools that I could SSH into?

For you I would actually give you a login on one of my systems.  But
instead how about if I send you a 'date' that is backported to
Squeeze?  Even though you say you love-to-hate it? :-)  Then you can
play with it and see the current behavior.

Bob

Message #23 received at 10455 <at> debbugs.gnu.org (full text, mbox):

From: Dotan Cohen <dotancohen <at> gmail.com>
To: Bob Proulx <bob <at> proulx.com>
Cc: 10455 <at> debbugs.gnu.org
Subject: Re: bug#10455: Date: Possible bug in ISO-8601 formatted dates
Date: Tue, 10 Jan 2012 09:26:23 +0200

On Tue, Jan 10, 2012 at 07:12, Bob Proulx <bob <at> proulx.com> wrote:
> For you I would actually give you a login on one of my systems.  But
> instead how about if I send you a 'date' that is backported to
> Squeeze?  Even though you say you love-to-hate it? :-)  Then you can
> play with it and see the current behavior.
>

Thanks, Bob. I checked with the backported date-8.13 and it performs
as expected for the test case mentioned. That is, the issue is
resolved.

I love to love Debian! I was just embarrassed to mention that I use
Kubuntu at home on a public mailing list. Here, I'm getting over it!
Hence, a love-to-hate Debian-based distro! The backported date ran
fine on Kubuntu. Thank you very much!


-- 
Dotan Cohen

http://gibberish.co.il
http://what-is-what.com

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