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

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.

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

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".

Thanks,

Derek