Great Question! i'm going to break this down first. So the earth spins on its pole which is called the axis and every 24 hours the earth makes a full rotation on it. Remember, the sun and the moon don't move around our planet. We get our light and darkness because the Earth spins and when it does, the moon is on one side and the sun is on the other. Let's get back to your question. "Why Do We Need Timezones?" We need them because if all the people on Earth set the clocks to the same time, noon would be the middle of the day in some places but in other places, it would be morning evening and the middle of the night. Since different parts of our Earth enter and exit daylight we need different timezones. That is why we have 24 time zones on planet Earth.