What you will need...
- a watch or a clock
- an open area of lawn (ideally at least 6m x 1.5m (20' x 5') for the sundial to work between 10 AM and 5 PM)
- stones (size is up to you) or other markers, 16 for the hours between sunrise and sunset in June
- a shadow-caster, your child
- head outside and place two stones to mark the spot for the shadow-caster to stand
- have the shadow-caster stand facing north (roughly) with their toes just touching the two stones
- wait for the top of an hour (e.g. 8, 9, 10, etc.) and place a stone at the tip of the shadow
- repeat Step 3 each hour on the hour (See Figures below to see how your sundial will look when done.)
- if you like, paint the hour number on each stone
A time-lapse animation is provided below the Figures showing how your shadow will move during the day.
See our time-lapse animation.
- Since the sun runs slightly ahead of or behind your watch time, depending on the time of year, you may want to adjust your sundial every couple of weeks or so. Simple fix, move the stones to match your watch.
- Probably more noticable than the sundial running fast or slow, the shadows will begin to get shorter as we approach the summer solstice (June 20 in 2020). Again, you can simply move the stones to match your watch.
- If you like, gather up more stones and add another row next month (preferably on the same day of the month), and the month after that, etc. In this way, you can see how much higher the sun gets between now and the first day of summer.
- After the first day of summer, you will notice the shadows getting longer again.