tl;dr – Ekadashi is a fast day that occurs twice a month, in synch with the moon phases, and is observed chiefly by followers of Lord Vishnu.
Ekadashī (एकादशी -“Eleventh” in Sanskrit) is the eleventh lunar day (tithi) of each of the two lunar phases which occur in a vedic calendar month – the Vedic, or Hindu, calendar is different to the Western calendar. The Shukla Pakṣa (the brightening moon also known as the waxing phase) and the Kṛṣṇa Pakṣa (the fading moon also known as the waning phase) both take 15 days to complete, and the 11th day of each is the ekadashi.
A devotee’s religious efforts can be spent in the following ways:
In the Brahma-vaivarta Purana it is said that one who observes fasting on Ekadashi day is freed from all kinds of reactions to sinful activities and advances in pious life.
Padma Purana states that one should follow Ekadashi especially since even if one by trickery follows Ekadashi, all of his sins are absolved and he very easily attains the supreme goal, the abode of Vaikuntha.
According to religious beliefs, a drop of sweat fell on the ground from Lord Brahma’s head and became a demon. When it asked for a place to live, Brahma told the demon to exist in the grains of rice consumed by people on Ekadashi and convert into worms in their stomach.
Another reason is that we have 5 sense organs, 5 organs for workand 1 nind. The mind controls all ten for proper functioning of the human body. If mind is well the whole body will be functioning properly and thus all 11 (ekadashi) organs are aligned.
This day is deemed important for fastng. One should avoid eating grains and beans, anything made from them or anything that contains them. This means avoiding bread, pasta, lentils, rice, as well as beans and preparations made from bean flour.
Ekadashi may be observed in different levels as given below and one may choose a particular level of fasting depending on one’s age, health and various other factors pertaining to one’s lifestyle.
The real way to observe Ekadashi is to fast completely without even taking water. This is called nirjala fast.
– If you cannot observe a nirjala fast, you can take just water.
– If you cannot do that, you can also take a little fruit and milk.
– The next option is that you can also take other non-grain foods like vegetables (except onion and garlic), roots, nuts, etc., only once during the fast.
– The last option is to take the above items three times like on a regular day.
– Observe Ekadashi vrata (fasting practice) from sunrise to sunrise.
Breaking the Ekadashi fast
Ekadashi fast must be broken next day after the sunrise.
If you have not observed a nirjala fast (a complete fast without even water), it should be broken by taking grains. In the case of a nirjala fast, you can break it with even non-grain items like milk or fruits.
The special feature of Ekadasi, as most people know it, is a fast, abstinence from diet. According to scientific research, it is known that the air pressure on the earth varies to extreme limits on both the new moon (Amavasya) and the full moon (Purnima) day. This is because of the orbital path combination of the sun, moon and earth.
This can be observed by the change in the nature of the tidal waves on the new moon and full moon days. The waves are very high and rough, but from the next day onwards, the waves become calm, an indication that the pressure has also receded. Now, based on this fact, the significance of Ekadasi fasting can be explained in 2 ways:
1) It takes about 3-4 days for the food that we eat today to reach our brain (for the brain to understand the food intake). Now, if we eat light/fast on Ekadasi days, that intake will reach the brain correspondingly on the New moon/full moon day. On both of these days, the earth pressure is at its maximum, thus leading to imbalance in everything, including ones thought process. So, if the input to the brain is at a minimum, the chances of the brain indulging in any wayward activity due to the high pressure imbalance also becomes minimum. People in asylums behave weirdly during ekadashis due to this same lunar activity.
2) Another explanation for Ekadasi fasting is that compared to any other day of the moon cycle, atmospheric pressure is lowest on Ekadasi days. Thus, this is the best time to fast and cleanse the bowel system. If we fast on any other day, the high pressure/strain may damage our system. Thus, it is advisable that after fasting on Ekadasi, on the immediate next day (Dwadasi), we should get up early and eat as soon as possible.
Sadhguru on Ekadashi fasting