As a side note to this post, I wanted to link to the first person to post such an article. If you search for '3 Types of Fun' on Google you get quite a few different search results back and no one gives anyone else credit (annoying) and none of the top hits had a date-time stamp I could find.

So, I found this article, which was very helpful:

https://www.technologyreview.com/s/513996/how-to-carbon-date-a-web-page/

Which linked to this thing:

http://cd.cs.odu.edu/cd/<YOUR_URL_HERE>

And yes, you really do paste your whole URL there, without the pointy-brackets. Here was one the queries that I ran:

http://cd.cs.odu.edu/cd/https://www.rei.com/blog/climb/fun-scale