Introduction
The Full Moon of the Teacher
Guru Pūrṇimā — also called Vyāsa Pūrṇimā — is the sacred full-moon day of Āṣāḍha (June–July) when Sanātana Dharma honors the Guru, the visible form of the Divine who removes the darkness of ignorance.
It commemorates the birth of Veda Vyāsa, compiler of the Vedas and author of the Mahābhārata; it is also the day Shiva began teaching the saptarṣis as the Ādi-Guru, and the day the Buddha gave his first sermon at Sārnāth.

