Why are the hours of daylight and darkness not equal on the Equinox here in Washington state?
Location determines when the hours and minutes of daylight and darkness will be equal. At our latitudes, day/night equality typically falls before the spring equinox, and after the fall equinox. This occurs because the sun isn't a 'point' of light, but about 1/2 degree wide, as seen from our perspective. Because our atmosphere 'bends' sunlight...that leads to an early 'apparent' sunrise and a late 'apparent' sunset...lengthening the day...or at least what looks like the 'day'.