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Time zones

Grade 4 · Geography · Free lesson

Hey there! Have you ever wondered why it is bedtime for you, but daytime for someone far away? Let's explore how our spinning Earth creates different time zones!

The Earth is shaped like a big ball. As it spins, the Sun can only shine on one side of the Earth at a time. This means when it is day on one side, it is night on the other side.

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To help everyone, we divide the world into twenty-four different time zones. Each zone is like a vertical slice of the Earth. When you move to the next slice to the east, the clock goes forward by one hour.

Earth Spins in the Sunlight

Imagine you live in Chicago. If you travel east to New York, you cross into a new time zone. Because the Sun rises earlier in the east, New York is one hour ahead of Chicago.

Chicago2:00 PMNew York3:00 PMGoing East adds one hour!
✏️ Worked example

Maya lives in Denver, where it is 4:00 PM. She wants to call her grandma who lives in New York. New York is two time zones to the east of Denver. What time is it in New York?

  1. Find the starting place and time. Maya is in Denver, and her clock says 4:00 PM.
  2. Find the direction you need to go. Grandma is in New York, which is to the east.
  3. Remember the rule: going east means we add hours to our time.
  4. Count the number of time zones. New York is two zones to the east, so we must add two hours.
  5. Add the hours: 4:00 PM plus 2 hours equals 6:00 PM. It is 6:00 PM in New York!
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