From watching the few AD episodes, it appears that they're dating this current season around late 1965 to early 1966. (Holy shit, that's as old as I am!
)
TV shows still place breaks where commercials can be added, usually at the end of an act, even though it may be shown as "with limited or no commercial interruptions". 10-12 minutes out of a 1 hour TV show is commercial time; most shows are about 48-50 minutes total time uncut. (Please correct me if I'm off the mark, DA...)
Don't think my fellow high school classmate (Jeff Zucker, president of NBC Universal Entertainment) is about to shit-can American Dreams. It's in a relatively decent time slot and still attracts decent ratings, spilling over from football/Dateline NBC/60 Minutes viewership.