Fun in the Sun

Sundial

Use the sun to help you keep time with a sundial, one of the oldest forms of clocks.

Materials

  • Sundial template (click here to download)
  • Scissors
  • Tape
  • A sharpened pencil
  • A piece of Bristol board or cardboard (optional)
  • A compass (optional)

Let’s get to work!

  1. Print the sundial template found on the next page and cut along the two dotted lines.
  2. Fold along the dashed lines with the printed side on the outside of the fold.
  3. Keeping the printed side facing you, fold along the solid latitude line that best represents your location. Use the list of latitudes for Canadian cities on the template – this will help you calibrate the angle of your sundial depending on where you live.
  4. Tape the flaps made by the fold along the latitude line to the rest of the paper (see image).
  5. With the sharpened end of the pencil, make a hole through the ‘o’ along the base of the semi-circle. Pass the pencil through about half way or until the paper can stand up on its own. The semi-circle is called the dial plate, and the pencil is called the gnomon (pronounced no-mon) of the sundial.
  6. Be sure the gnomon makes a right angle with the dial plate. You may need to tape the end of the pencil to the paper to hold it in place.
  7. To make the sundial more stable, you can tape the entire structure to a piece of cardboard or Bristol board.

What time is it?

Go outside on a sunny day, place your sundial on a horizontal surface and point the gnomon directly north (use your compass if you are not sure which way is north).

The shadow of the pencil should indicate what time it is in Standard Time. Depending on the time of year, the shadow may fall on the underside of the dial plate, it should still indicate the correct time if you can see the numbers through the paper.

Take note!

Add one hour to your sundial time if it is Daylight Savings Time.

What happened?

As the Sun travels across the sky during the day, the angle of its shadow will change, so we can use it to tell the time. The Sun’s light rays hit the Earth at different angles depending on how far north or south you live. The latitude lines increase the accuracy of the sundial no matter where you live in Canada.

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