301 Redirects for Changed Permalink Structure & Category Base

I’m redeveloping a site on a fresh WP install. The old site had the following permalink structure:

domain.com/CATEGORY/POSTNAME/

The new site has the following permalink structure:

domain.com/YEAR/MONTH/POSTNAME/

I need to set up a 301 redirect in htaccess that correctly redirects the old posts. I’ve found a lot of rewrite rules for the opposite way (YEAR/MONTH/POSTNAME/ to CATEGORY/POSTNAME/) but none for the way I need.

I prefer not to use a plugin. It appears that all the redirection plugins don’t work. But, if Dean’s Permalink Migration is recommended I’ll use it.

WordPress actually 301’s these out of the box! It handles a number of basic structures by default, so unless you’re switching to or from a very unique configuration (e.g. /blog/%postname%/), it will probably work.