Subject: Re: bug#37130: 27.0.50; Tar mode should use the ISO8601 format to display the timestamps (or support TIME_STYLE or locales)

From: Lars Ingebrigtsen <[email-masked]>
Date: Sun, 25 Aug 2019 08:03:21 +0200

Eli Zaretskii <[email-masked]> writes:

>> I think it makes sense to follow GNU tar's lead here, so I've now done
>> this on the trunk.
>
> Yuck! what an ugly format!

Yes, I didn't check what GNU tar really did, so I just put in ISO8601.
I've now checked and replicated the format, which looks nicer.

>> > Other formats (e.g. one corresponding to the locales) could be used
>> > via an option; in particular, the support of the TIME_STYLE
>> > environment variable (see coreutils manual) would be a good idea.
>> 
>> I think that sounds like overkill for tar-mode, but perhaps there should
>> be a general function somewhere for using TIME_STYLE throughout Emacs
>> whenever time/dates are displayed.
>
> I think we should just make the format used for the time stamp a user
> option, that would be a good-enough solution.  It will also provide a
> "fire escape" to get the old behavior for those, like me, who might
> dislike the ISO8601 format.  We must provide such
> backward-compatibility options anyway when we change behavior in
> incompatible ways.

We don't, in general, add such options unless we think it's going to be
used a lot.  For tar mode, my feeling is that nobody will ever care
enough to bother to customise it.

> Finally, this change should be in NEWS (including the to-be-added
> backward-compatibility shim).

Or even notice it, which is why I didn't mention it in NEWS.  It seem
like a not particularly NEWS-worthy item to me.

If you think this really warrants a user customisation and a NEWS item,
I'd rather just revert the change and mark this bug as a WONTFIX,
because it doesn't seem like that to me.

-- 
(domestic pets only, the antidote for overdose, milk.)
   bloggy blog: http://lars.ingebrigtsen.no