According to old traditions, the day starts with the auspicious 'Govardhan Pooja', after which sisters used to specially pray to Lord Yama (God of Death) for the safe and long life of their brothers.
After the prayer, the sister applies 'Tilak' and offers sweets to her brother. It serves as homage to the pious brother-sister relationship.
There is this old saying that Lord Sun and his wife Goddess Chhaya bore two children, son Lord 'Yama', and daughter Goddess 'Yamuna'.
