Earth is about 25,000 miles circumference. Therefore each time zone is approximately 1000 miles wide. There is a method to the madness.
Yes, that is 3rd grade geography, at least in my day. The proposal, which I didn’t endorse but find intriguing, says that it will be more efficient if we compress the time zones in our country. It did not deny that there is a method and reasoning behind the existing time zone system.
I have long noticed that the way the Greenwich lines come out when they reach our shores is that the east coast and the west coast have much of their time zone in the sea. If we started at Maine, eastern time would extend much farther west, and that alone might reduce it to 3 time zones.