Can someone help me show the end date?

That's not in Arastta and Second theme, it's some extension or modification you're using - and you don't provide any useful info.

I recommend you read this (ref Ask Questions The Smart Way): https://arastta.org/forum/forum-rules

Dear, Rune Rasmussen,
The forum is not the idea of ​​being useful and sharing between users?

This is neither an add-on nor a modification. This is a one-line correction in a tpl file ... the question is if any other user has an idea, what is the stance to visualize the end date of the promotion to this product ...
I think this would be useful for everyone, because consumers will be able to receive timely information on how to reduce the price and when it is valid!

If you're unable to provide any understandable useful info, nobody can help you. It's as simple as that.

And no matter if it's a modification or a extension, it's not a issue of Arastta, and has nothing to do in the issue tracker at GitHub - it's for core issues only.

I simply don't understand your one line posting above, probably doesn't anyone else neither, since nobody did care to reply. So if you want help, you need to help other understand your problem by posting understandable useful information and clear questions, and not just one-liners nobody can understand. Your posting indicated it did work, but stopped working ...

So your question is how to do this I guess, you'r asking for someone to post all changes you need to make it work?!
Maybe someone is willing to write that code for you then.

Hello again,
Depending on the legislation of individual countries, this information is mandatory. That is, the final date of validity of that promotional price.

The addendum I want affects the producer file, but I'm not aware of the $special - outputs the reduced price correctly, and the $special ['date_end'] not show the end date of the specified price.

I hope I have clearly explained my problem and found a user who can help.