Possibly a useful hint:
The Radio Times website offers possibly the best TV guide there is:
http://www.radiotimes.com/tv/tv-listings/
You can personalise the listings by selecting your provider at the top of the page or by using the 'My Channels' button. (If you register and log in you'll always have your preferred listing immediately available to you).
More importantly here though, simply clicking on the name of a channel (in the left hand column) shows which platforms it's on, together with the channel numbers for those platforms.