I would like to alter the delivery date of my NOW Broadband box
The router is delivered by Royal Mail and tracked. So you should be able to sort it when you get the number to track it with.
I'm not sure its possible to alter the delivery date, it comes when it comes.
It is trackable once its been sent out for delivery though - and if there is no one available to sign for it upon delivery then it will end up somewhere like the local post office where you can collect it - as that's what happened to me