Appraisal period

Hi Gurus,

My client is having 02 appraisal periods like "Appraisal validity Period" which is an validity period of appraisal document. And also they are using another period call. " appraisal campaign process period"

i can assign the  validity period but I don't know how to assign the " appraisal campaign process period" in the header area.

can anyone assist me?

regards

DInesh