Don’t cache last post for 30 hours

Great plugin! Thank you for simplicity in a complicated world ??
I am an artist.
I post a new painting about four times a month.
The first 24 hours of that post, the painting is in an auction built into the post. There is a timer in the post which removes visibility of the auction portion of the post after 30 hours. The auction itself uses its own timer and halts bidding after 24 hours.

I am thinking it would be best if the post is not cached at all for 30 hours. After that, cache forever. Reasons being the updating of the bids, login/registration/logout of bidders, and email responders going out when bids are placed.

In other words, “the last post needs to remain dynamic for 30 hours”. After that it can be cached since the dynamic need no longer exists.

So, that stated, is there a way to throw a function or something in my functions.php file that will accommodate this need for a 30 hour window for only the LAST post? I’m not a php/javaScript programmer but technically savvy enough to understand a solution.

I do realize the login/reg/logout etc. will be added to the “don’t cache” box in settings. So I’m not concerned with those.

On a side question…is the admin side of the site cached??? I wouldn’t want it to be.

Any assistance would be greatly appreciated ?? Help a starving artist as we say ??

James