In a former role, I had some SEO responsibilities and was asked to run lots of experiments around dates on page - in the URL, in the title or first H1, in the b

In a former role, I had some SEO responsibilities and was asked to run lots of experiments around dates on page - in the URL, in the title or first H1, in the body, in the metadata, etc. None of them seemed to make a material difference. I suspect Google uses its own first crawl as a created date, and has some minimum threshold for last updated date that's at least somewhat contextually aware, and that just swapping a date out is done so often automatically that it's not used as a signal. YMMV with other search engines, of course.