Margashirsha Purnima is a significant day in Hinduism, falling on the full moon day (Purnima) in the Hindu lunar month of Margashirsha, which typically corresponds to November or December in the Gregorian calendar. This day holds religious and spiritual significance and is observed in various ways across different regions of India.

“Purnima” (Puranmashi) is a Sanskrit term meaning “fullmoon.” In Hinduism and several other Indian religions and cultures, Purnima holds significant spiritual and religious significance. It occurs on the fifteenth day (Purnima Tithi) of the lunar month in the Hindu calendar, typically every month. Margashirsha Purnima is one of the twelve Purnima or Pooranmashi occurring in a year.

One of the main rituals associated with Margashirsha Purnima is the worship of Lord Vishnu, particularly in his form as Matsya, the fish avatar. Devotees may observe fasts, perform puja (worship), and offer prayers to Lord Vishnu on this day. It is believed that observing these rituals with devotion can bring blessings, prosperity, and spiritual growth.

In some regions, Margashirsha Purnima is also known as Dev Diwali or Kartik Purnima. It marks the end of the Kartik month and the beginning of the Margashirsha month. It is considered an auspicious day for taking holy baths in sacred rivers like the Ganges, Yamuna, or Godavari. Taking a dip in these rivers on Margashirsha Purnima is believed to cleanse one of sins and bestow spiritual merit.

Margashirsha Purnima is associated with several mythological events and legends in Hinduism. Here are a few notable ones:

1. Birth of Matsya Avatar: According to Hindu mythology, Margashirsha Purnima marks the day when Lord Vishnu took his first avatar (incarnation) as Matsya, the fish, to save the first man, Manu, from a great deluge. This event is described in the ancient scriptures like the Matsya Puran and the Bhagavad Puran.
2. Kartik Snan: It is believed that on this day, the gods descended to earth to bathe in the holy rivers. Hence, taking a bath in sacred rivers like the Ganges, Yamuna, or Godavari on Margashirsha Purnima is considered highly auspicious and purifying.
3. Dev Diwali: In some regions, Margashirsha Purnima is celebrated as Dev Diwali, the festival of lights of the gods. It is believed that on this day, the gods defeated the demons, and to celebrate their victory, they illuminated the heavens with lamps and lights. Devotees light lamps and offer prayers to the gods on this day.
4. Guru-disciple Tradition: Margashirsha Purnima is also associated with the Guru-disciple tradition. It is believed that Lord Shiv, the Adi Guru (the first guru), imparted knowledge to the seven sages (Saptarishis) on this day. Therefore, it is considered auspicious for spiritual seekers to begin their journey or receive initiation from a guru on this day.

These mythological events add depth and significance to the observance of Margashirsha Purnima, making it a sacred and auspicious day in Hinduism.