Dhan Teras or Dhanvantri Trayodashi is observed two days prior to Dewali, the Hindu Festival of Lights. It is held in honor of Dhanvantri, the physician of the gods and the father of Indian medicine, whom doctors in particular worship on this day. According to Hindu mythology, the gods tried to produce the elixir known as amrita by churning up the ocean. Dhanvantri rose up out of the water bearing a cup filled with it. On this day Hindus rise at dawn and bathe, put on new robes, and fast. In the evening, they light an earthen lamp before the door of the house and break their fast. Discuss
Source: The Free Dictionary