As far as I know there's no way to know the exact time the FedEx driver will be around to deliver your package.
The only thing you will know for sure is the date the package is to be delivered.
FedEx usually delivers to my address and neighborhood around 2:00 PM but that time does change as sometimes they deliver earlier than that and sometimes later depending on how backed up they're with packages.
If you're waiting for a package to be delivered through FedEx you'll have to just wait around especially if you're required to sign for the package.
If you don't need to sign for the package then you don't have to hang around the house until delivery as they will just leave the package at your door.