New Year's Eve TV coverage questions

Yes, I realize it’s odd to ask these questions in May:)
–Here on the West Coast, the broadcast networks tape delay their coverage and Times Square ball drop until midnight local time. Have they always done this? What do they do in the Central and Mountain zones?
–I often watched Johnny Carson as a kid. As I recall, the New Year’s show would be exactly the same as other shows until midnight. Then confetti would rain down and the screen say “Happy New Year!” Was this done only on the West Coast? Or was this a fake “live” event seen across the country?
–In the Seattle area, we see the Space Needle celebration. Do other cities or regions have their own local New Year’s celebration broadcast?

In Central time, they usually show it live, and then re-air the whole thing again at midnight.