Tomorrow is the vernal equinox, the official beginning of spring.
(The word equinox comes from the Latin words aequus for equal, and nox for night).
Because our planet doesn’t orbit upright but instead is tilted on its axis, the equinox is the time when the Northern and Southern hemispheres trade places in receiving the sun’s light and warmth most directly.
That occurs twice each year, once in spring and once in fall, when the tilt of the Earth’s axis and Earth’s orbit around the sun combine in such a way that the axis is inclined neither away from nor toward the sun.
At this point, the Earth’s two hemispheres receive the sun’s rays equally, and night and day are approximately equal in length.
As an inhabitant of the Earth’s Northern Hemisphere, you may have noticed over the past weeks that the sun has been rising earlier and setting later. You may have noticed, too, that the sun at sunrise and sunset has gradually been changing its position southward and northward.
And if you live on a curving highway as I do, it's also fun to know equinox day is a good time to determine due east and due west from your property. Simply stand at a certain spot and watch to see the points at which the sun rises and sets, in relation to other landmarks on your property. Those two points are due east and due west!
Now you know! Whether you wanted to or not!