sort by date with natbib?

[km]

Is there a way to sort references within the text by date with natbib? Using
\usepackage[sort]{natbib} only sorts by order they appear in the .bib file
(in my case alphabetically by year).

I work in the natural sciences, where references typically are written as
(Jones, 1992; Brown, 1995). Such that, although Brown comes alphabetically
before Jones, Jones is cited first by date.

I'd be willing to get into the natbib.sty file if someone has any idea how
to do this sort of thing. I don't have much experience with that myself.

Thanks
K