Is there a way to make the related section in the sidebar show its dates?

No new development is being done on this site.

Nope.
Just post your response. Sometimes it will revive an old question and start a whole new discussion.
That seems to be the way Fluther was designed to work. An ever growing body of knowledge.

Working as intended

I am new to the collective and have answered some older questions which I assume is permissible because fluther allowed me to answer. I have even answered some questions where the asker apparently is no longer on the site.

@prairierose Yup – that’s allowed.

@janbb Okay thanks because some of the older questions are interesting.

The problem with answering old questions is that very few people will see your answers. It does not bump a question to the top of the list like it does with a forum so the only people who will see your response are those who previously participated in the question, assuming they are still on the site and have not un-followed the thread.

You may run into questions that are closed for discussion, too, @bomyne and @prairierose. They are the only questions on Fluther that you cannot participate in.

@downtide – If one chooses the “Active” button for sorting, those posts are bumped up.

I personally get a kick out of seeing old posts resurface (well, most of them).

Not only what @downtide said, but sometimes the old post isn’t even relevant anymore.

The related sidebar only care for questions with related topics to the question you’re viewing. Beside that, it doesn’t care for anything (hence the name “related”, otherwise it could have been called “recent related”)

When I first joined, I answered some old questions too. I guess new jellies don’t care much for the date like older ones (you seem to be an exception @bomyne). That’s what the Davey Jones’ Revenge award is for, for encouraging jellies to answer and read old questions.