How are supplies pegged to the demands?

Summary:

In the supply plan, supplies are pegged to demands which are in far future in addition to near future demands. The items don't have such a large shelf life. How to make sure the supplies are pegged to the demands ONLY in near future so that Shelf Life of items won't be exhausted by the time this item is supposed to be used for the demands?
Supply plan is with daily buckets.

Example: we have the planned orders to show Suggested Dock Dates only on certain day based on supplier. For eg, supplier 1 will show planned orders with Suggested Dock Dates only on Mondays. So the 1st Monday shows demands also pegged to it from 2, 3 months in future. Item does not have such a long shelf life. If it gets ordered right away, it cannot wait for 2, 3 months in the warehouse for the demand in future because it will be wasted.