See the map Since countries are free to choose ... Just like there are time zones across the United States, there are time zones around the world to reflect the Earth's rotation around the sun.

They introduced time zones in the United States. It took some doing--they had to convince all the major cities to go along with it, get over some objections that the railroads were stepping on ...

Just like there are time zones across the United States, there are time zones around ... International date line zig zags through Pacific. See the map Since countries are free to choose which ...