Hi there! Just before we got your question, we had updated the text to make this clearer. It is not the noon on a clock but the local, or solar, noon, when the shortest shadow occurs. Local noon is the time when the Sun crosses the North/South line (local meridian) and is highest in the sky for the day. Unfortunately, the difference between clock time and solar time is a bit complicated. There are formulas/calculators online to help you determine when local noon is in your area (it involves latitude, longitude, time zone, and some other data). Hope this helps!
Hi there! Just before we got your question, we had updated the text to make this clearer. It is not the noon on a clock but the local, or solar, noon, when the shortest shadow occurs. Local noon is the time when the Sun crosses the North/South line (local meridian) and is highest in the sky for the day. Unfortunately, the difference between clock time and solar time is a bit complicated. There are formulas/calculators online to help you determine when local noon is in your area (it involves latitude, longitude, time zone, and some other data). Hope this helps!