The Radio Times online TV listings show that Doctor Who Series 7 Episode 3, A Town Called Mercy, will be broadcast in the United Kingdom on Saturday 15th September at 7:35PM on BBC One and BBC One HD.
The episode is 45 minutes long and concludes at 8:20PM, which does mean that if the current listings stay the same, The X Factor will once again overlap by 20 minutes.
The synopsis for the episode can be seen below:
3/14. The Time Lord and the Ponds get mixed up in a Wild West adventure as the Doctor becomes the reluctant sheriff of a town under siege from a relentless cyborg who goes by the name of the Gunslinger. But who is he and what does he want? It seems the answer lies with a mysterious alien whose initial appearance hides a dark secret.
As always, the air date and time is subject to change until 10 days before broadcast when listings are locked.