I broke my permalinks

In the course of moving my wordpress installation to another server, I apparently switched my permalink structure (without realizing it) from /year/month/day/postname to /archives/year/month/day/postname. I’m not exactly sure how or why I managed to do that. In any case, now I’ve got 404s showing up from existing links to my site before the move.

mod_rewrite seems powerful enough to fix this, but I don’t know enough about it or regex to come up with a solution. Can someone help me find a way to rewrite the URIs without /archives/ to include it?