If you write a non fiction book that says "world war I was the cause of world war II" you are entitled to copyright protection for your expression. However, you

If you write a non fiction book that says "world war I was the cause of world war II" you are entitled to copyright protection for your expression. However, you don't earn a monopoly on the notion that WWI cause WWII even if you were the first to express that. Someone else can still write a book that conveys that fact. The "creative work" isn't the fact that country a is in time zone b. That's just data. A description of the process and the reasoning used to reach that conclusion, and an analysis of available facts is an expression. A map visualizing the data is an expression. A formatted chart is an expression. The connection between regions and timezones is just data. It's not protectable.