SNP Time horizon in the planning book

Hello all,

We have weekly buckets in our SNP planning book right now. Everytime one enters the planning book, the time horizon starts only from the current week.

We want to change this to have the past week also in the time horizon.

Could any of you tell me how this can be done and if it can be done, will there be any problem in seeing data in the past week?

thanks!

PV