The very lengthy discussion around the concept was fascinating to me as a 23 year old college student who only knew it from one perspective.
Japan had a whole fancy temporal hour system before Western contact. It was more complicated than our modern framework, as it was based on the time between sunrise and sunset and so the length of the hours had to be adjusted about every two weeks. But they certainly thought quite a bit about it, so I'm not sure how it could be claimed to not be a concept there at the time.
All you need to create a clock is realize that your oil lamp consumes its fuel in a somewhat consistent interval, or a similar observation for the time it takes drips of water to fill a cup. People figured it out.
That really doesn't seem to make sense as written. Even if for "Western" you count all the way to the Middle East (where much of our chronometry originates), there's still a lot found in China and the New World. (From what I can tell, India does not seem to have a strong independent record here? Though they certainly borrowed from the inventors, just like Europe did.)