How does "Unanswered" system works?

I clicked on UNANSWERED link at the top of web page and I am getting unanswered questions from March, June, January etc.

Is there a way to have sort by “time” (latest question at the top) and also by unanswered (so zero at the top)? Current sorting returns strange (= not useful) results.

From Settings … Data entry and display rules:

What should “unanswered question” mean?

Default value (and selected): Question has no accepted answers

(Alternatively: Question has no answers)

You can sort the “unanswered questions” as follows:

Sort » by date » by activity » by answers » by votes

(in ascending/descending order).

You may select: Sort » by activity.

See also this question on “unanswered questions” answered also by @manj_k which references a yet earlier version of this question answered by @cloph.