Timezone as per dictionary meaning is - 'Any of the 24 regions of the globe (loosely divided by longitude) throughout which the same standard time is used.' Different countries follow different time ...

Navigating between varying time zones is on the cards with world clocks and time zone maps, that provide global users with a visual representation of different time zones, allowing them to quickly ...

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.