Yeah, I've done that. Usually it's because I had a long post that took a couple of days to write, so when I first posted it as private, it had the original date, then I'd change the date when it went public so that it would show up at the top of a reading list.

One thing to remember. If you start getting other Dreamwidth users subscribing to your journal, they will usually be using their reading list to view your posts rather than going to your journal and reading them there. I finally had a chance to check my list today, and saw not only your posts, but Alex's too.