About old posts
When I redesigned this site for 2019, I took a lot of miscellaneous materials I had and turned them into “blog posts.” Some of these older materials were things that I had posted as part of other section of the site, such as teaching. I decided they made more sense as miscellany in the “blog,” so that they could still be found by anyone looking for them. Some of them were things like talks and papers that didn’t have their own pages on the old site.
In any case, the days in the posts were intended to approximate the date the that topic of the page was developed. For anything before 2019, the text on the page probably came later that the post date.