Re: git-archive doesn't support --date= option for %ad & %cd format:<string>'s

On Thu, Oct 09, 2014 at 11:19:36AM -0500, Derek Moore wrote:

PRETTY FORMATS' format:<string> documentation says, "%ad: author date
(format respects --date= option)", and similarly for %cd.

But git-archive does not support the --date= option for changing the
date format in $Format:%ad$ or $Format:%cd$ substitution strings.

Correct. You can use %ai, %aD, etc to pick a format. But...

Relatedly, I want a short RFC date, not a short ISO date, but there is
only --date=short, which is ISO.

If you start adding new formats, we are likely going to run out of
reasonably-memorable letters.

We've discussed something like "%ad(rfc822)" in the past, and I even had
a patch:

  http://article.gmane.org/gmane.comp.version-control.git/168512

but it got bogged down in a discussion on potentially expanding the
placeholder syntax to something more regular (probably
"%(authordate:rfc822"), like for-each-ref does. That's from 2011, and I
doubt anybody is working on it now.

Would introducing --date=shortrfc and --date=shortiso be feasable,
with --date=short aliasing to --date=shortiso. With a shortrfc, I
could recreate SVN $Date$'s, which would be equivalent to $Format:%ai
(%ad)$ when used with "git archive --date=shortrfc".

I don't see a big problem with that. But I wonder if we would do better
to introduce arbitrary strftime-like formatting, so we do not have to
keep adding new formats.

-Peff