To use, put a date in the input field (defaults to today's date) and click on the enter button. Then either use the time lapse button to watch the shadows (grey) move or use the slider to find the approximate shadow positions at a specific time (noon to sunset). Late in the afternoon, the sun is low enough to reach underneath a covered section (yellow).

If you click near the center of a section of the stands, the section number will be displayed (this might take a couple attempts to hit the target). It works best on a tablet or larger screen; for smaller screens you will have to adjust the image size.