Ekadashi is the eleventh day (Tithi) of each lunar fortnight in the Hindu calendar. There are two Ekadashis every month -- one in Shukla Paksha (waxing moon) and one in Krishna Paksha (waning moon), giving approximately 24 Ekadashis per year. Fasting on Ekadashi (Ekadashi Vrat) is one of the most important observances in Hinduism, believed to purify the body and mind. Each Ekadashi has a unique name and spiritual significance tied to stories from the Puranas.