These 2 fields are interrelated according to the Default Safety Lead Time field (under Manufacturing Setup). By default, the Due Date is the same as the Demand Date, but you can change this as you like.
Ti dve polji sta medsebojno povezani v skladu s poljem Privzeti varnostni pretočni čas (pod Nastavitev proizvodnje). Datum zapadlosti je privzeto enak kakor datum zahteve, vendar to lahko spreminjate kakor želite.