Kati Snan, also known as Katik Snan or Kartik Snan, is a significant ritual bath observed by Hindus during the Hindu lunar month of Kartik, which typically falls in October or November of the Gregorian calendar. It is considered an auspicious and purifying event in Hinduism, especially among those who follow the Vedic traditions. Kati Snan is usually observed during the early morning hours, and devotees immerse themselves in a sacred river, such as the Ganges, Yamuna, or other holy water bodies. The bath is believed to cleanse one's sins and bring blessings and good fortune. It is also considered a way to honor Lord Kartikeya, the son of Lord Shiva and Goddess Parvati, who is associated with this month. Devotees often offer prayers, light oil lamps, and perform other rituals before and after taking the holy dip. Many people also fast on this day and engage in acts of charity and devotion.
Kati Snan is particularly important in places like Varanasi, Haridwar, and Prayagraj (formerly Allahabad), where the confluence of rivers and the availability of sacred bathing sites draw large crowds of pilgrims during Kartik month.
It's worth noting that the specific customs and traditions associated with Kati Snan may vary across different regions of India and among various sects of Hinduism.