The spiritual significance of fasting is being forgotten today as man is losing contact with his inner being. Nevertheless the science of fasting, as preserved in the Vedas and Shastras, is a method of purification which can aid man in his mundane and spiritual life. These ancient texts are inherited from our ancestors who understood and were in tune with the law of nature and man. The systems they devised came from their profound knowledge and enable man to raise his consciousness into the higher realms.
It has been scientifically proven that fasting makes the mind calm and serene. In yogic terminology this is known as the sattvic element. Because the mind becomes predominantly sattvic and more receptive, the scriptures advise the worship of certain deities during these fasting periods. This is called vrat, a specific type of purifying austerity or tapa. In the 'Tapovanshant Paras' fasting is referred to as param tapa, or supreme austerity.
When the positive aspects of a particular deity are concentrated on, those qualities are ultimately evoked in the individual. The deities are not actually separate beings; they are aspects of the dormant mind waiting to be awakened and utilized in man's consciousness. Worship can arouse these potential faculties so that the low, sensual consciousness can be elevated to super-consciousness.
The systems propounded in the Vedas and Shastras coordinate man's biological rhythms with the cycles of nature. One of nature's most fundamental rhythms can be observed in the phases of the moon. Scientifically it is known that the tides of the ocean rise during full moon and by dark moon they have completely ebbed. These phases must therefore affect the human body, considering it is approximately 70% water. The systems of fasting are based on the different stages of the moon's waxing and waning. The cycles of the moon influence women in particular through the menstrual cycle, so fasting is practised more extensively by women.
There are two phases in the moon's monthly cycle. The first part consisting of fifteen days as the moon waxes, is known as Shuklapaksh or the white fortnight. On the fifteenth day, Poornima or full moon occurs. Then the second half begins as the moon wanes. The next fifteen days are referred to as Krishnapaksh. By the fifteenth day, or Amavasya, it is completely dark. The days specified for fasting are calculated according to the intensity of the moon's influence during these two phases. Fasting can be done on the fourth days of either fortnight. This is known as Sankashta Chaturthi. This is a time for the worship of Ganesha, the remover of obstacles and troubles. From this comes the name Sankashta, meaning 'obstacles'.
The eighth day of each fortnight is called Astami. Although fasting is not normally practised on every Astami, it is of importance on special occasions, such as the birthday of Krishna, Gokul Astami. On this day the divine qualities of Krishna are remembered and revered. Navaratra Astami, in the Shuklapaksh of Ashwini, during November-December, is devoted to the aspects of Devi, and fasting is done with respect to Durga and Kali.
The ninth day, Naumi, is the next significant date. The birth of Rama, Ramnaumi, is especially noted.
The eleventh day of either fortnight, Ekadasi, is one of the more important dates for fasting. According to 'Skanda Purana' fasting on Ekadasi serves as a preventive medicine. This is of most relevance during Chaturmas, the three months of monsoon. At this time maximum fasting is done because the weather is not conducive to digestion and the quality of available food also degenerates as a result of the climate. From the first Ekadasi, Harishayani Ekadasi, in Ashada, July-August, up till the eleventh day in Kartik, November-December, some people eat only once a day. It is said that the god Hari goes to sleep during this period; it is like a time of hibernation. Nirjala Ekadasi is observed in Jyestha. As the name indicates, no water is to be drunk on this day.
The monsoon period of fasting is not only exclusive to India. In the Islamic religion, during Ramadan, in the ninth month of the Arabian year, food and drink are prohibited in daylight hours. Obviously, in countries where monsoon does not occur, maximum fasting will not be so essential at this time. One has to adapt the rules to the conditions of the climate in which he lives.
The most relevant and popular periods for fasting are Poornima, full moon, and Amavasya, no moon. These times are recommended for young and unmarried youths in particular. On Buddha Poornima in Baishakh, May-June, fasts are done by devotees of Buddha. Guru Poornima is for all disciples to offer homage to their gurus. Maha Shivaratri, which falls on the Amavasya in March, is noted as the time when Shiva, consciousness, was married or united, with Parvati, energy. This particular Amavasya is very significant, because it is supposed to be the darkest night of the year. However, any Amavasya falling on a Monday is also noted with special reverence to Shiva.
Other fasts which don't fall on particular dates can be done weekly on one specific day. Monday fasting is done in reverence of Shiva. Tuesday is for pleasing Ganesha or Devi. Thursday is in worship of Guru Dattatreya, the tri-headed form of Brahma, Vishnu and Mahesh. On Friday Santoshi Ma is worshipped and on Saturday blessings from Hanuman can be granted. One specific day is taken by an individual in accordance with his personal being. This is often allotted under the guidance of the guru.
Unmarried girls perform fasts and worship to have good husbands in marriage. This is called Jaya-parvati Vrat because Parvati performed austerities and fasts to win Shiva as her husband. Young girls take this up in the ninth month of Ashada, July-August. Married women fast at the time of Vatasavitri in Jyestha, June - July, praying for their husbands' longevity. It is said Savitri rescued her husband from the grip of Yama, the lord of death, and brought him back to this world to rest under the banyan tree. Thus fasting and worship of the banyan tree is recommended at this time.
On various fasting days different types of fasts are specified. When one meal is taken in the afternoon this is called Eka Bhukta. Eating once at night is called Nakta Vrat. To fast completely or take only a little fruit is Upavas.
India, of course, being divided into many sects and religious groups, supports systems of fasting depending on local beliefs and climatic conditions. Jams, for example, will fast for one day, one week, one month, or even until the final samadhi occurs. Only boiled water can be taken twice a day. The fasts are done to induce a state of non-violence, ahimsa, in all acts. By fasting the aim is to rise above the influence of the five senses. Therefore, these fasts are very strict. Other groups fast on a single food, depending on climate and availability, some eating only wheat at certain times, others only rice. For some, grains are forbidden, and only fruit and/or dairy products are allowed. The whole of man's external and internal conditions are taken into consideration.
We too can adopt these systems of fasting to help us in our daily lives no matter what our profession is, where we live, or which religion we have faith or no faith in. These systems were formulated and recorded to enable all people to go beyond individual consciousness and experience the real essence of life. Fasting is systematically advocated in the scriptures in order to align the physical and subtle bodies with the whole cosmos, enabling sustained equilibrium in every aspect of life.