[Kojak]

Otherwise keeping it essentially to 40 minutes in primetime but having that defined at 18:00-22:00 would both still give viewers an hour of peak time relatively ad free, but also give broadcasters an extra hour later in the evening where they can add another 12 minutes.  Indeed that might encourage more post-10pm commissioning, although would likely mean News at Ten being News at 10:04 even more often.

Or I daresay even the end of News at Ten? I suspect that should your idea become reality, we might see ITV tempted to once again experiment with different programmes at 10 (*cough*The Nightly Show*cough*). I can see how it would at least make films more viable in primetime (particularly on a Sunday or Friday).