Paush Purnima occurring on the 15th day of the Shukla Paksh (waxing phase) in the Hindu calendar month of Paush, heralds the arrival of the full moon. It serves as an unofficial inauguration of the Maha Kumbh Mela, signifying the commencement of this grand event. Additionally, Paush Purnima marks the initiation of Kalpvasa, a period of intense spiritual practice and devotion observed by pilgrims during the Maha Kumbh Mela.