uttrayan - dakshinayan

The six months of the northern path of the sun, the path of light, of fire, of day, of the bright fortnight, leads knowers of Brahman to the supreme goal. The six months of the southern path of the sun, the path of smoke, of night, of the dark fortnight, leads other souls to the light of the moon and rebirth.

- Bhagavad Gita 8:24-25