Why do u think new York City has the nick name the city that never sleeps

It is because it is shown in the 1977 song "New York, New York," recorded by Frank Sinatra

I think that there is so much activity in that city that happens around the clock that there is always at least a handful of people who are awake and doing something.

it is also a famous city so many people visit, sometimes from different time zones

I think it's like a big commerce hub so many people pass through it alot and at different times