Google has some neat tools, click the "tools" menu and select any time, you can enter a range there: https://imgur.com/a/XQSMT9n
Not that I ever needed to use it, but it's there.
Google does know an indirect date of the page even if it's not written explicitly. The first crawling date should be saved and if no better indicator exists I'd assume they are using that timestamp.
I have a feeling that OP has used this feature and that it's part of their complaint.
I've been using it for many years by now, and have essentially given up on it recently.
I'd often set for past year/month and get articles, reviews, etc that were clearly dated many years previous. I don't know if the site are responsible for the gaming of search, or Google themselves, but the result is the same. I have some doubt that PC hardware review sites are gaming dates on their old articles, although I accept it could be in their interest to do so too.
I'm in the minority of the HN crowd who has very little issues with Google search quality. (although I do see some spam in my native language) My account is getting adolescent old, so it might have learned a thing or two about me how to serve me best.
But this isn't about search quality - it's about finding some web page (otherwise obscured by similar keyword webpages) that you know that could only have been created at a specific time.
Not that I ever needed to use it, but it's there.
Google does know an indirect date of the page even if it's not written explicitly. The first crawling date should be saved and if no better indicator exists I'd assume they are using that timestamp.