Upawasa or fasting in antiquity of India

Albiruni visited India in 10th century, in his Tarikh-e-Hind, describes about the various kind of fasting by Hindus, it is interesting to read it in this time.

Fasting is with the Hindus voluntary and supererogatory. Fasting is abstaining from food for a certain length of time, which may be different in duration and in the manner in which it is carried out.

Various methods of fasting.
The ordinary middle process, by which all the conditions of fasting are realised, is this: A man determines the day on which he will fast, and keeps in mind the name of that being whosebenevolence he wishes to gain thereby and for whose sake he will fast, be it a god, or an angel, or some other being. Then he proceeds, prepares (and takes) his food on the day before the fast-day at noon, cleans his teeth by rubbing, and fixes his thoughts on the fasting of the following day. From that moment he abstains from food. On the morning of the fast-day he again rubs his teeth, washes himself, and performs the duties of the day. He takes water in his hand, and sprinkles it into all four directions, he pronounces with his tongue the name of the deity for whom he fasts, and remains in this condition till the day after the fast-day. After the sun has risen, he is at liberty to break the fast at that moment if he likes, or, if he prefers, he may postpone it till noon.

This kind is called upavˆasa, i.e. the fasting; for the not-eating from one noon to the following is called ekanakta, not fasting. Another kind, called kr. icchra, is this: A man takes his food on some day at noon, and on the following day in the evening. On the third day he eats nothing except what by chance is given him without his asking for it. On the fourth day he fasts. Another kind, called parˆaka, is this: A man takes his food at noon on three consecutive days. Then be transfers his eating-hour to the evening during three further consecutive days. Then he fasts uninterruptedly
during three consecutive days without breaking fast. Another kind, called candrˆayan. a, is this: A man fasts on the day of full moon; on the following day he takes only a mouthful, on the third day he takes double this amount, on the fourth day the threefold of it , going on thus. till the day of new moon. On that day he fasts; on the following days he again diminishes his food by one mouthful a day, till he again fasts on the day of full moon. Another kind, called mˆasavˆasa (mˆasopavasa), is this: A man uninterruptedly fasts all the days of a month without ever breaking fast.

Reward of the fasting in the single months.
The Hindus explain accurately what reward the latter fasting in every single month will bring to a man for a new life of his after he has died. They say: If a man fasts all the days of Caitra, he obtains wealth and joy over the nobility of his children.

If he fasts Vai´sˆakha, he will be a lord over his tribe and great in his army.
If he fasts Jyaisht.
ha, he will be a favourite of the women.
If he fasts ˆAshˆad. ha, he will obtain wealth.
If he fasts ´Srˆavan. a, he obtains wisdom.
If he fasts Bhˆadrapada, he obtains health and valour, riches and cattle.
If he fasts ˆA´svayuja, he will always be victorious over his enemies.
If he fasts Kˆarttika, he will be grand in the eyes of people and will obtain his wishes.
If he fasts Mˆarga´sˆırsha, he will be born in the most beautiful and fertile country.
If he fasts Pausha, he obtains a high reputation.
If he fasts Mˆagha, he obtains innumerable wealth.
If he fasts Phˆalguna, he will be beloved.

He, however, who fasts during all the months of the year, only twelve times breaking the fast, will reside in paradise 10,000 years, and will thence return to life as the member of a noble, high, and respected family. The book Vishn. u-Dharma relates that Maitreyˆı, the wife of Yˆajnavalkya asked her husband what man is to do in order to save his children from calamities and bodily defects, upon which he answered: “If a man begins on the day Duvˆe, in the month Pausha, i.e. the second day of each of the two halves of the month, and fasts four consecutive days, washing himself on the first with water, on the second with sesame oil, on the third with galangale, and on the fourth with a mixture of various balms; if he further on each day gives alms and recites praises over the names of the angels; if he continue to do all this during each month till the end of the year, his children will in the following life be free from calamities and defects, and he will obtain what he wishes; for also Dilˆıpa, Dushyanta, and Yayˆati obtained their wishes for having acted thus.”