The centre line of the Noon Mark points to true north, and is aligned along the meridan of the longitude North 83 degrees, 01 minutes, 34.03 seconds West. When the sun totally illuminates the narrow space between the two upright wings, it is local noon. The sun is at its highest point in the sky and directly over the meridian. The shadow cast by the protruding needle is facing true north at local noon.

As the sun travels across the sky between New York City, Windsor and Thunder Bay- our watches all read 12:00 p.m., yet the sun is in different locations in relationship to these separate spots on the earth. The Noon Mark shows us the exact time when the sun is directly overhead in Windsor- it tells us our local noon.