Regarding telemarketing, many years ago I had a summertime-ish job where we would call people about various buys.
There was the renewal of TV Guide and other magazines at a lower price than what would be offered when the publication sent renewal notices.
Then were the weird things - a set of specially designed commemorative coins
by some "renowned" artist . (I'd never heard of him before then). We called people who had made similar purchases before.
There was some sort of exercise equipment. People had sent in one of those magazine insert postcards, which included their phone number.
And cold calls to entice people to go take a look at a new housing development. Supposedly quite nice, although, a fellow worker informed me, it was across the road from a garbage dump.
Gosh, such (NOT) fun times.
We called until 9:30 pm (that is, 9:30 pm in the client's location, which meant until just past midnight in the eastern time zone was fine to call people on the west coast)
Worked even less time doing surveys over the phone. These were all cold calls and covered all sorts of things. Bathroom remodeling, types of beer, etc. Here too, we would call until it was 9:30 pm in the time zone farthest to our west.