Dev Deepawali, also known as the Festival of Lights for the Gods, is a Hindu festival celebrated on the full moon night of Kartik Purnima, typically in November. Celebrated prominently in Varanasi, the festival involves lighting thousands of diyas along the Ganga ghats and devotees taking a holy dip in the river. The festival commemorates Lord Shiva's victory over the demon Tripurasura, marking the descent of gods to Earth for a holy dip. Key traditions include Deepdan (offering oil lamps) and the Ganga Aarti.