Circle of illumination is the circle that separates day from the night.
Circle of Illumination
- The circle of illumination is the circle that divides the day from night on the globe.
- It takes 365¼ days (one year) for the earth to revolve around the sun.
- Six hours saved every year are added to make one day (24 hours) over a span of four years. This surplus day is added to the month of February. Thus, every fourth year we have a leap year with 366 days.
- Earth goes around the sun in an elliptical orbit. Note that throughout its orbit, the earth is inclined in the same direction.