The times and channels, as listed by the announcement, are listed below.
UK – 7:20pm GMT on BBC One/BBC One HD
US – 9:00pm ET on BBC America
Canada – 9:00pm ET on Space
This is great news for US & Canadian Whovians, as sources had previously given the airdate as September 8th. Now nobody has to worry about posting or reading spoilers on Twitter and Facebook! At least, no more than usual.