Expiring Content for Promotions

ruler

Hi Gurus,

We are redesigning our site and we have some promotions on it, we want to build the some of the DCR's content with launch date and expire date into it. and write a script that does bring the content up during active promotion and brings it down when the promo is inactive.

Could some one point me to some code that would help me proceed this direction.
I will really appreicate your help.