My preference would be for it to commence on a Thursday or Friday afternoon and wrap up on the Monday evening.It makes no sense having the trade week any longer than 5 days. It's not like clubs don't talk to each other prior to trade week once they are made aware of a players wishes.
As you've said, the clubs, players and managers are well aware of the state of play. It would likely cut through half the rubbish low-ball offers and tough talk that tends to plague the majority of the trade period.