Hm, I think something's missing from the post... Oh, yes, proper attribution.

I saw this months ago in a 2010 blog post: http://www.jukie.net/bart/blog/pimping-out-git-log

It's the exact same alias, sans "--date=relative".

The guy from jukie.net also shares his entire .gitconfig, I built mine from it and highly recommend at least taking a peek: http://www.jukie.net/~bart/conf/gitconfig