When I was young, if you stayed up late enough watching TV, this (or something similar) would play as the station went off the air. Literally, nothing on TV after that until morning. With streaming services and the internet today, younger people would find this incomprehensible.

Today: if you deposit cash in an ATM after bank hours, the bank is "off the air" and you get a notice on the screen that the transaction will be processed next business day. Young people of the future will find this incomprehensible.