Why is it that the t.v. spots for Conan O'Brien say 11:00pm but it comes on at...

[Roi]

...10:00pm PST (on Dish Network)? Why is it that the t.v. spots for Conan O'Brien say 11:00pm and when I tune in at the time, Lopez tonight is airing... who is supposed to be on at 12:00am. I live in San Jose, CA and I watch TBS on channel 139 using Dish Network. I've searched the net looking for an answer but I have been unable to find sufficient information. Is it just a programming difference that Dish Network involuntary imposes or something else? Thanks in advance