Kartik Purnima, the full moon day in the Hindu month of Kartik (October-November), is one of the most sacred days in the Hindu calendar, revered for holy bathing, charitable acts, and spiritual devotion. This auspicious day is known by several names — Dev Diwali in Varanasi (when the gods celebrate their own Diwali on the ghats of the Ganga), Tripuri Purnima (commemorating Lord Shiva's destruction of the three demon cities, Tripurasura), and Guru Nanak Jayanti in the Sikh tradition (celebrating the birth of the first Sikh Guru).
The mythological significance of Kartik Purnima is multi-layered. It is believed that Lord Vishnu awakes from his four-month cosmic sleep (Chaturmas) on this day, making it highly auspicious. The day commemorates Lord Shiva's destruction of Tripurasura — the three invincible cities of the demons — earning him the name Tripurari. It is also considered the day Lord Kartikeya (Murugan) was born, making it especially sacred in South Indian temple traditions. For Jains, it marks the Nirvana of Lord Mahavira.
The most spectacular celebration occurs in Varanasi, where Dev Diwali transforms the ghats into a river of light. On this night, every ghat along the Ganga — from Assi Ghat to Raj Ghat — is illuminated with thousands upon thousands of earthen diyas placed on the steps leading down to the river. The sight of the illuminated ghats reflected in the dark waters of the Ganga is one of the most breathtaking spiritual spectacles in the world. A grand Ganga Aarti is performed, and the river comes alive with floating diyas set adrift by devotees.
Kartik Purnima is also the concluding day of the sacred month of Kartik, during which devotees observe special vratas (fasts), take daily early-morning holy baths (Kartik Snan), light deepdaan (lamp offerings) at river banks and temples, and practice heightened devotion. At Pushkar in Rajasthan, the famous Pushkar Mela (camel fair) coincides with Kartik Purnima, and a holy dip in Pushkar Lake on this day is believed to bestow the merit of performing a hundred yagnas (fire rituals).
