Does 'Overnight' change for British Summer Time?

[#1]

The website states overnight as being from midnight to 8am; does this stick to GMT, or does it change with BST?

[#2]

Changes with BST. So whatever your clock says is what you should be using as a guide (assuming your clock isn't an hour out of course ;))

[#3]

So when people (*cough*Jojo*cough*) say you get an extra free hour of unmetered usage, remember it was robbed from you 6 months earlier.