There is already a countdown in mcb.cloud (layout element->Shop Advanced->Countdown timer), but it is general and is displayed on all pages that use the layout you enable it on.

It could be good with a countdown, which could be related. It could then, for example, appear on a product that is at a reduced price for a certain period of time and count down until the price rises again. It could also be a countdown to Black Friday, but where it is only visible on the related items (articles, pages, product group, items, etc.). If it is related to an item with variants, you should be able to choose that the countdown may only be active on some of the variants.

Here is a screenshot from frishop.dk