Today is the Vernal Equinox. In plain English, it is also called the Spring Equinox, or the first day of the Spring.
The day is called Equinox to imply it is the day of the equal day and night. Wherever you on the Earth, that is. Whether you are near the tropics or near the poles. Little hard to believe, but true.
If you are standing somewhere on 13 degree North latitude in Bengalooru, India, here is how the Sun’s path goes aound the sky. The yellow line indicates the path of the Sun, and the little yellow disk represents the Sun.
On the other hand, if you were somewhere in the temperate lands, such as the San Fransisco bay area, this is how the Sun’s path would look like.
Now, this is what happens if you go much to the North – say somewhere near Anchorage, Alaska.
What if you go down South, to Sydney, Australia or Johannesburg, South Africa?
At each place, you may notice the Sun rises in the true east, and sets in the true west. And this is the reason why the day and night are of equal length everywhere today.
All the pictures were captured using the solar simulation tool here: