Divination is the art of telling the future by means of signs and portents has been practiced in India, from time immemorial, known as ganakata, 'reckoning' or pratibha, `imaging', it has a rich specialized vocabulary derived from the objects viewed or examined for divinatory purposes.
These objects the raw material of divination, so to speak, cover a very wide range. Prognostications were made by observing the omens in nature, including all atmospheric phenomena, particularly lightning and rain. Omens were also read during sacrificial ceremonies from the direction of the rising altar smoke (see prabhava) or the behaviour of the victim (see human sacrifice).
The custom of interpreting the significance of moles, wrinkles and other marks of the body to determine the destiny of a person is of extreme antiquity. Dreams of course present an inexhaustible field for divinatory interpretations; telling fortunes from shadows, fire, numbers and so forth are of medieval origin.
Astrology is based on the belief that human destiny is influenced by the heavenly bodies acting both singly, as in the case of the sun, moon, planets and conjointly in groups as in constellations. From the disposition of the planets at the time of one's birth the future is calculated in a personal horoscope. An analogous method is used for determining the outcome of any enterprise. The science of horoscopy was first known in Sanskrit as horashastra, the word hora being derived from the Greekhora, 'hour', and numerous Sanskrit works on hora-shastra are extant. Later, horoscopy came to be called jataka or 'nativity. Horashastra by Bhattotpala and tajikas by Nilkantha.
In India, the stars are consulted in all important undertakings, from setting an auspicious time for weddings, business, transactions, travel, building houses and bridges or digging wells and taks, to sowing and harvesting and declaring war.
Great stress is laid on favourable and unfavourable times for holding ceremonies performing rites, and in the daily round of one's work. There is a minimum and maximum period for which the stars can possibly influence a person or an event. The minimum period is known as the muhurta lasting 408 minutes, and in the event of danger it is this period that is to be guarded against at all costs.
The maximum span of a planet's influence is also rigidly determined according to astrological laws. The full extent of all planetary influences over a man is said to last 108 years. Out of this any man may be influenced by each planet for not more than a fixed number of years.
In theory, the maximum bad luck period possible for a man to have would be a succession of the worst aspects of Mars, Saturn and Rahu, i.e. 30 years.