Calibrating Stonehenge

Sol in my sights If you live, as I do, in the central United States and haven't yet calibrated your backyard Stonehenge, it's possible you (1) forgot, (2) enjoy stress, or (3) procrastinated your time away, and in fact have no actual scale model of Stonehenge at all. Assuming you aren't in that nearly unthinkable third category, you're running precariously close to the deadline, but there's still hope.

By Saturday evening our sun will have already begun its slow southerly drift, which means we'll soon be scraping our windshields again, and crying ourselves to sleep in order to stay warm. Although Friday's sunset will occur at exactly the same time as today's and tomorrow's, by Saturday it will be happening one minute earlier, and then it all goes to hell from there.

So that's it. You have a couple days to align your rocks, your plastic chairs, your permanently mounted rifle scope, or whatever you happen to be using to track the exact point of the setting sun, because after that it's too late. No Stonehenge for you, and you won't know what day it is, ever.