Dhanteras is the first day of the start of the festival of Diwali in India. It is also known as Dhanatrayodashi. It is celebrated on the thirteenth lunar day of Krishna Paksha in the Hindi calendar month of Ashvin. On the day of Dhantrayodashi, Goddess Lakshmi came out from the ocean of milk during the churning of the Sea. Hence, Goddess Lakshmi is worshiped on the day of Trayodashi. Furthermore, the God of Ayurveda Dhanvantari is also worshipped on the occasion of Dhanteras. It is believed that God Dhanvantari bestowed the wisdom of Ayurveda for the betterment of mankind and to help rid it of the suffering of disease. Dhanteras is also celebrated as the National Ayurveda Day which was announced by the Indian ministry of Ayurveda, Yoga and Naturopathy, Unani, Siddha, and Homeopathy. It was first observed on October 28, 2016.
According to an ancient legend, there was a 16-year-old son of King Hima. His horoscope predicted that he was going to die from a snake bite on the fourth day of his marriage. So, to keep him safe on that particular day, his newly-wed wife did not allow him to sleep. She laid out all her ornaments and many gold and silver coins in a heap at the entrance of the sleeping chamber and lit many lamps. Then she narrated stories and sang songs to keep her husband from falling asleep. When Yama the god of Death arrived at the prince's doorstep in the form of a snake, his eyes were dazzled and blinded by the brilliance of the lamps as well as the jewelry. Yama could not enter the Prince's chamber, so he climbed on top of the heap of gold coins and sat there the entire night listening to the stories and songs that were narrated to King Hima’s son. In the morning, he silently went away. Thus, the young prince was saved from the clutches of death by the cleverness of his new bride, and the day came to be celebrated as Dhanteras.
There is another popular ancient legend according to which when the devas and asuras performed the Samudra Manthan for Amrita. During this Samundra Manthan, God Dhanvantari who is the god of Ayurveda and an incarnation of Vishnu emerged carrying a jar of immortality on the day of Dhanteras.
In Jainism, this day is celebrated as DHANYATERAS instead of DHANTERAS meaning the auspicious day of the thirteenth. It is said that on this day Mahavira was in the state of leaving everything in this world and meditating before Moksha which made this day auspicious or DHANYA.
Dhanteras is the day of worshipping Lord Dhanvantari. According to Hindu Mythology, Lord Dhanvantari emerged during Samudra Manthan holding a Kalasha full of Amrit in one hand and the sacred text about Ayurveda in the other hand. He is considered to be the Vaidya of God. Furthermore, on the day of the festival, Lakshmi Puja is performed in the evenings, and Diyas are lit. Bhajans in praise of Goddess Lakshmi are sung. Furthermore, Naivedhya traditional sweets are offered to the Goddess Lakshmi. A peculiar custom in Maharashtra exists where people lightly pound dried coriander seeds with jaggery and offer the mixture as Naivedhya.
On Dhanteras, people also clean and whitewash their houses thoroughly in preparation for Diwali and Lord Dhanvantari is worshiped in the evening. The main entrance is decorated with colorful lanterns and lights as well as traditional motifs of Rangoli designs are made to welcome the Goddess of Wealth and Prosperity. To indicate her long-awaited arrival, small footprints are drawn with rice flour and vermilion powder all over the house. Also, Diyas are ritually kept burning all through the night in honor of Lakshmi and Dhanvantari.
Hindus consider this an extremely auspicious day for making new purchases, especially of gold or silver articles and new utensils. It is believed that new "Dhan" (wealth) or some item made of precious metal is a sign of good luck. In modern times, Dhanteras has come to be known as the most auspicious occasion for buying gold, silver, and other metals, especially kitchenware. The day also sees heavy purchases of appliances and automobiles.
Apart from this, from the night of Dhanteras, the lights are set out every night both in the sky lamps and as offerings at the base of a Tulsi plant. Furthermore, people lit Diyas which are placed in front of the doorways of homes. This light is an offering to Yama to avert untimely death during the time of the Diwali festival. This day is a celebration aimed at increasing wealth and prosperity. Dhanteras engages themes of cleansing, renewal, and the securing of auspiciousness as embodied by Lakshmi. Furthermore, farmers in the villages adorned and worshiped their cattle as their main source of income.