Pretty date option for git tag?

It is relatively hard to verify the date a tag was created unless it was been
gpg/pgp-signed at the time of creation, no? I suppose that the Unix timestamp
included in each tag file is useful for sorting, but it's not very easy for
people to digest.  Additionally, we have our `log.date` config, why not use it
here for some sort of option, like `--pretty=date` to make it easy to see when
a tag was created?

I.e.

$ git tag -l --pretty=date
...
Mon, 13 Apr 2009 00:06:25: v1.6.3-rc0
Sat, 18 Apr 2009 22:11:00: v1.6.3-rc1 
Sat, 25 Apr 2009 06:01:13: v1.6.3-rc2 
Sun, 26 Apr 2009 23:43:48: v1.6.3-rc3 
Sat, 02 May 2009 06:32:21: v1.6.3-rc4 
Wed, 13 May 2009 05:30:37: v1.6.3.1

I don't know if this is feasible. Perhaps there already exists a feature for
this that I'm unaware of. Or maybe this would be a waste of time.

Dan