No these are simply a reflection of the top 30 links of HN captured every hour. It's pulling them from HN's rss feed.

The point here is to find something that was at the top a number of days ago.

I sometimes also find that I like a bunch of the posts on HN that I want to read at a later time, and then I don't refresh HN for a while, because I'm scared to lose those links. With HN History I don't have to :)