Karva Chauth is a one-day festival celebrated by Hindu women from North India, four days after purnima (a full moon) in the month of Kartika. Like many Hindu festivals, Karva Chauth is based on the lunisolar calendar which accounts for all astronomical positions, especially positions of the moon which is used as a marker to calculate important dates. The festival falls on the fourth day after the full moon, in the Hindu lunisolar calendar month of Kartik.