We have passed th winter solstice by roughly 2 weeks. Seems to me that we have already gained quite a few minutes til sundown. Seems like the summer solstice brings a more subtle (longer) sundown time. I am at 36’N. Please explain the difference. Example: where I live in NC, sundown is stated at 8:30 pm in June and July. In December, sundown is 5pm. January has skipped back to 5:30
Picking Greensboro, today you’d have a sunset at 5:19. That’s 41 minutes “early” fifteen days after the solstice. Fifteen days after the summer solstice is July 6. Your sunset then will be 8:40 pm. Of course that’s only 7:40 standard time, but that’s 100 minutes late. Why the difference? One reason is that while the solstices are the shortest and longest days, they are not the earliest and latest sunsets (or sunrises). The latest sunset for Greensboro occurs June 29th. The earliest December sunset is 5th or 6th.
Another reason is that we go by standard time rather than sun time. Even on the equinoxes the sunset is late in Greensboro. It will be 6:31 (EST or 7:31 EDT) on March 21 and 6:19 (7:19) on September 21st, so you can see that Greensboro sunset is 19 to 31 minutes late on average in any case.
Finally, the earth’s orbit is not a circle, but an ellipse. We are a bit closer to the sun in the winter than the summer and move faster in our orbit then. I think this has some effect, but don’t know precisely what.
It is due to analemma. The offset of earliest sunset and latest sunrise either side of the solstice is typically a week or two, depending on latitude. The effect is less pronounced at the summer solstice, due to the Earth’s elliptical orbit.
Here’s a link to calculate a table of sunrise/sunset times for the year.
You might have noticed that while your earliest sunsets were a little before the solstice, your latest sunrises are right around now, a little after the solstice.