The earliest sunset

The earliest sunset
My part of the world was gray, dreary, dark, cold, and wet today. But it had one thing going for it, one very big thing: the sun set this afternoon a few seconds later than it did the day before. Ordinarily I wouldn’t bother splitting hairs over astronomical minutiae, but it helps get me through December to recall that, although the total number of daylight hours will keep shrinking until the 21st or so, the sunsets are now occurring later and later every day and so will continue until late June. Mmmmm… June. Why does the earliest sunset not match the shortest day? Here is a helpful diagram with ellipses and annotations to explain it.

Confusing ellipses

I hope that’s clear. If I work at it, I can understand how it all works for an hour or so, but then it fades.

3 thoughts on “The earliest sunset”

  1. Two years ago, around this time, I tuned in to WZLX and heard the morning guys talking about the shortest day of the year. They made the common mistake that the earliest sunset must be on the shortest day of the year. I couldn’t get through on the phones to them in time, so I sent them e-mail pointing to StarChamber and the excellent reference. Sadly, I don’t think I got any of them to say “analemma” on the air.


  2. Ned says: “I can understand how it all works for an hour or so, but then it fades.” Sounds like an old Star Trek episode – Spock’s Brain. McCoy: “I never should have done it – I never should have reconnected his mouth.”

  3. Hard to figure in Sweden in the summer how the sun rises in the northeast and sets in the northwest – but that’s what happens so near the arctic circle.

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