Why Things Aren't Equal on the Equinox

[Red Baron]

Last Tuesday at 8:07PM, the sun was directly over the equator. In the spring that event is called the vernal equinox; in the fall it is the autumnal equinox. The name equinox means equal night, so why are the sunrise and sunset times around the equinox not equal as the name would suggest :?:



 :idea: The reason for the discrepancy is that the sunrise is calculated as the sun breaks the plane of the eastern horizon, and sunset is when the last edge of the sun dips below the western horizon. The equinox is calculated from the center of the sun, which breaks the plane a few minutes after the edge in the east and a few minutes before in the west.