Wrap this around your mental astronomy phenomena spindle and see if you can make of it more skein than snarl!
The Autumnal Equinox in 2026 occurs at 5:05 PM PDT on Tuesday, 22 September 2026. (Please don't call it the first day of autumn or I will have to hit you with my Summer Solstice Is Midsummer bat.)
"Equinox" means that, on that day, the time from sunrise to sunset should be equal to the time from sunset to sunrise, right?
Hah! Doesn't work that way.
Wednesday actually has about 5 more minutes of daylight than Friday. On Friday 25 September we actually get a length of day that is 12 hours 1 minute and 22 seconds. And Saturday 26 September has a time between sunrise and sunset that is 11 hours 58 minutes -- so Saturday the 26th is actually this year's winner in the Autumn "Day = Night" contest.
Why?
First, the astronomical definition of equinox refers to the moment the earth, in its orbit around the sun, crosses a particular point in reference to what astronomers call the fixed stars. Plus, we must remember that "Day Equals Night" day wanders because of the earth's axis-wobble with respect to the earth's elliptical orbit. This wobble is known as the precession of the equinox. The precession happens ve-e-e-r-r-y s-slo-o-o-owly (!) but it it make a difference. At this point, a difference of some days.
You're welcome.
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