The September equinox* arrived today at 20:02 UTC (1.02 pm here in my outpost on the globe), ushering in autumn. So for a moment, night and day are each 12 hours long**, sunrises are due east and sunsets are due west, for all creatures on the globe. The sun’s position crosses the celestial equator (an imaginary equator above the real one on Earth’s surface), and this happens no matter where one is on Earth.
*Equinox from Latin equi (equal) and nox (night).
**Precisely speaking, there is more daylight than nighttime on the day of the equinox, an additional 8 or so minutes of daylight, at mid-temperate latitudes.
