Start of Kartika month by North Indian calendar reckoning

Kartika Begins marks the start of the holy month of Kartika in the Purnimanta calendar followed across North India, beginning on the day after Ashwin Purnima. Kartika is regarded as the most sacred month of the year. The Skanda Purana declares that there is no month equal to Kartika, no age equal to Satya Yuga, no scripture equal to the Veda and no tirtha equal to the Ganga. It is dear to Lord Vishnu, who awakens from his four-month Yoga Nidra on Dev Uthani Ekadashi within it, and it is also called Damodara Masa, after the child Krishna whom Yashoda bound with a rope (dama) at the waist (udara). Through the month devotees take the Kartik snan before dawn in rivers or at home, offer a lamp (deepdaan) every evening to Vishnu, at the tulsi and in the sky (akash deep), worship the tulsi plant, and sing the Damodarashtakam. The month holds Karwa Chauth, Ahoi Ashtami, Dhanteras, Diwali, Govardhan Puja, Bhai Dooj, Chhath, Tulsi Vivah and Dev Deepawali on Kartik Purnima. Even small acts of devotion and charity in Kartika are said to bear imperishable fruit.

Many keep a satvik diet through Kartika and give up one food (such as brinjal, urad or onion-garlic) as a vow.