display a post at certain times

Hello,

We want to change our main website, and I decided to go for WordPress. Almost everything that I want (need) is there, but I only have trouble finding a plugin (or something else) to help me with one option that I want.
I want an offer (or news) to be displayed at our site, only for a certain time. So today I want to put in 3 offers, and Iwant that they are visible as follows : Offer 1, from monday to friday, Offer 2, only on monday and Offer3, from wednesday till saterday (and so on).
I know that i can do it manually, but why do I use a computer then :).

Hope that someone has some extra info for me.

Greetings,

Hans B.