filename cycling according to age, not name

[Kai Grossjohann <kai@emptydomain.de>]

Normally, I'm happy with the normal filename completion behavior of
zsh.  (After I've customized it to my liking.)  But from time to
time, I would like to say "give me the newest file under the foo
directory".

Is there a way to do this?

The ideal would be that I enter a partial filename (say "foo/") and
then hit a key, and it inserts the newest file in that directory
("foo/x"), and then I hit the key again and it replaces the filename
with the second-youngest ("foo/a").  Right now, the TAB key does
something similar, but it sorts by filename, not by age.

Right now, I have a function which does { ls -lt "$@" | head -15; }
and then I copy and paste, but I'm sure it can be done in a more
convenient manner.

Kai