(The sun rising for example)
Marsala wine, which is similar to a fortified port, is kept at a cool room temperature. Until opened, it should last for a very long time, but once it's opened, personally, I would use it or drink it within a month or two, keeping it cool but not refrigerated.
... comes in a screw-cap bottle, and I just close it up and put it back in the liquor cabinet...
I actually find that Marsala keeps for years pretty much even after opened as long as it is stored in a cool dark place.
America's Test Kitchen had a whole episode on Chicken marsala and urged you to use SWEET marsala instead of dry. I was skeptical ...
Since it was a dish I make pretty frequently, I tried it with sweet marsala and it was terrific. Not too sweet, nicely balanced.
Here's the recipe: Perfect chicken from America
I'm sorry to disagree with you, but I made Veal Marsala once with sweet Marsala by mistake, and it was DREADFUL. We threw it out and went with the accompanying spaghetti instead.
I also don't consider America's Test Kitchen to be any byword for what is good or best in food. And I am not alone in my feelings about them.