Ekathshi comes twice in a month according to the Hindu calendar. It falls on the eleventh day of the waxing moon (Sukul Paksh) and again on the eleventh day of the waning moon (Krishna Paksh).

Ekathshi is very significant for a Hindu, as the observance of rituals connected with this occasion is said to take away any sin that he or she may have accumulated during the fortnight. To be able to absolve oneself from sin every fifteen days is very helpful to the mind, and, in any case, it focuses the memory on the wrongs done during that fortnight, thereby acknowledging a wrong bahaviour or deed, and cleansing one's mind for the future. It is similar to the Christians going to their priest for 'confession'.

The very religious observe a fast on both the Ekathshis of the month. The fast regulations are not very strict as fruit, milk, sweets, tea and coffee are allowed and anything made of root vegetables can be taken once in a day. There is no restriction on drinking water at any time. A full meal (vegetarian) is taken at night. Still, even for the very religious there is a way out. A visit to the sacred dhaam (pilgrimage town) of Jagannath Puri in Orissa will absolve one from keeping the fast. According to folklore, Sri Krishna (who has his abode in Jagannath Puri during Kal Yug) got fed up with 'Ekathshi' turning up every fifteen days and hung her upside down and declared that those who saw her in this condition need not ever keep the vrat (fast) again.