London, Ontario is 5 hours behind London, England. So if they wedding starts at 9am London England time, it will be 4am in London Ontario
Coverage of the Royal Wedding is scheduled to start at 4 a.m. EST April 29th in the US. 4 a.m. EST 3 a.m. CST 2 a.m. MST 1 a.m. PST
The wedding starts 11am UK time. NY is 5 hours behind UK, so it starts 6am NY time. Coverage on CNN starts at 4 am EST and at 3am on PBS.
6am Eastern.