Kalpavas (Sanskrit: कल्पवास) is a month-long spiritual tradition in Sanatan Dharma (Hinduism) that involves a period of deep spiritual practice, austerity, and detachment from worldly life, practiced by staying near the bank of a holy river.
[1][2] In Hindu scriptures, Kalpavas is said to be the combination of Sanyaas and Vanprastha Ashram.
[3][4][5] Kalpavas is a combination of the Indic words Kalpa and Vas.
On this basis, Kalpavas, is said to remain on the banks of the Ganges for a certain period of time.
The certain period of time is one month in general but according to capacity of devotees, it could be reduced to 5, 11 or 21 days.