Dattatreya Jayanti celebrates the birth of Lord Dattatreya, a divine incarnation believed to embody the trinity of Brahma, Vishnu, and Shiva. He is revered as a teacher (Guru) and an incarnation of divine wisdom. Dattatreya Jayanti falls on the Purnima (full moon) day of the Margashira month (November–December), though the date may vary according to regional calendars.

Devotees observe this day by offering prayers to Lord Dattatreya in his various forms, as a symbol of knowledge, devotion, and spiritual guidance. The day marks the beginning of a new spiritual journey and is observed with fervor in many temples dedicated to Lord Dattatreya, especially in Goa, Maharashtra, and Andhra Pradesh.

The puja begins with holy bathing, followed by the installation of the idol or picture of Lord Dattatreya, typically seated with his three heads representing Brahma, Vishnu, and Shiva. Offerings of fruits, flowers, and incense are placed before the idol. Devotees chant the Dattatreya Ashtakshara Mantra, Dattatreya Stotra, and Dattaguru Mahimna Stotra, invoking the blessings of Lord Dattatreya for spiritual enlightenment and guidance.

Some devotees observe fasting and night vigils (jagarana), chanting his name and seeking protection from spiritual obstacles and karma. In temples, special rituals, including abhishekam, homa, and bhajans, are performed.

Lord Dattatreya is also considered the protector of the Guru-Disciple tradition, and the puja is said to bring peace, prosperity, and spiritual wisdom, guiding devotees towards self-realization.