CHART TWO
Moving with the great wheel of time, the stars and constellations travel clockwise around the polestar, and the sun travels with them. The sun, however, encircles the polestar in its own counterclockwise orbit around Sumeru, and therefore the sun's motion is seen to be different from that of the wheel of time itself. Passing through twelve months, the sun comes in touch with the twelve different signs of the zodiac and assumes twelve different names according to those signs. The aggregate of those twelve months is called a  samvatsara , or an entire year.
The sun travels at different speeds. When it travels in its northern course, it travels slowly during the day and quickly at night, thus increasing the duration of the daytime and decreasing the duration of night. When it travels in its southern course, the exact opposite is true—the duration of the day decreases, and the duration of the night increases.