Ekadashi

Tamil: ஏகாதசி, Bengali: একাদশী'Ekādaśī' (Sanskrit: एकादशी, Telugu: ఏకాదశి, ekādaśī, "Eleven"), also spelled as Ekadasi, is an auspicious day which occurs twice in a Hindu calendar month. It is the eleventh lunar day (tithi) of each of the two lunar phases which occur in a Hindu calendar month – the Shukla Paksha (period of the brightening moon also known as waxing phase) and the Krishna Paksha (period of the fading moon also known as waning phase).

In Hinduism and Jainism it is considered a spiritual day and is usually observed by a partial fast. Beans and grains are not consumed during Ekādaśī because it is believed that they are contaminated by sin. Only fruits, vegetables, and milk products are eaten during Ekādaśī. This period of abstinence runs from sunrise on the day of Ekādaśī to sunrise on the following day.

Hindu rules state that anyone between eight years and eighty years old should fast, which includes not drinking water. However, people who are sick, have health issues, or are pregnant are exempt and may take light food including milk and fruits.

Two Ekādaśīs occur in one month, according to positions of the moon. The progression of the moon from full moon to new moon is divided into fifteen equal arcs. Each arc measures one lunar day, called tithi: The time it takes the moon to traverse that distance is the length of that lunar day. Ekādaśī refers to the 11 tithi, or lunar day. The eleventh tithi therefore corresponds to a precise phase of the waxing and waning moon: In the bright half of the lunar month, the moon will appear roughly 3/4 full on Ekādaśī, and in the dark half of the lunar month, the moon will be about 3/4 dark on Ekādaśī.

There are 24 Ekādaśīs in a calendar year. Occasionally there are two extra Ekādaśīs that happen in a lunar leap year. Each Ekādaśī day has particular benefits and blessings that one can attain by the performance of specific activities.

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Wikipedia