The FTC maybe? Per Federal laws that time happens to be the upper limit for commercial fundraisers, debt collectors, and sales callers in the US, seven days a week. Of course it's not yet clear from this young thread what type of call is at issue.
Called my line first. Said "my name is", laughed then hung up. 15 minutes later my wife gets a call on her phone. Said they were from southwest. Told them it was not appropriate to call after 9PM.