akregator: What's special about 7 Feb 2016?

I’m using akregator ( = akregator5) for tracking some blogs. It is set to show the articles in order of date, with the newest first.

For several blogs, the article at the top of the list has a date “7 Feb 2016”, though there are more recent articles than that.

Come to think of it, articles are supposed to be expired after 30 days. So I should not even have those in the akregator archives. Presumably the problem started with “akregator4”, the version in 42.1. For those articles should already have expired under that older version.

So I can manually delete them, and they probably won’t come back. But I’m wondering what is special about that date. Did akregator change its archive format at that date?