Dhanteras (Hindi: धनतेरस), also known as Dhanatrayodashi (Sanskrit: धनत्रयोदशी), is the first day that marks the festival of Diwali in India.
It is celebrated on the thirteenth lunar day of Krishna Paksha (dark fortnight) in the Hindu calendar month of Kartik. Dhanvantari, who is also worshipped on the occasion of Dhanteras, is considered the God of Ayurveda who imparted the wisdom of Ayurveda for the betterment of mankind, and to help rid it of the suffering of disease.