How can I automate the publish/unpublish process of a product?

[a1ex]

Hi everyone, I have difficulties in creating products for flash sale. I want the products to be viewable on the frontend automatically at a set time, say tomorrow 9am. And after 24 hours, it automatically unpublished and disappear from the frontend. And During the sale period, there is  a countdown timer (e.g. "sale ends 15hr, 34min"). Can somebody tell what is the easiest way to achieve this? Thanks, Thanks!!