In astrology, a horoscope is a chart or diagram representing the positions of the Sun, Moon, planets, the astrological aspects, and sensitive angles at the time of an event, such as the moment of a person's birth. The word horoscope is derived from Greek words meaning "a look at the hours" (horoskopos, pl. horoskopoi, or "marker(s) of the hour.") Other commonly used names for the horoscope in English include astrological chart, astro-chart, celestial map, sky-map, star-chart, cosmogram, vitasphere, radical chart, radix, chart wheel, or simply chart.
It is used as a method of divination regarding events relating to the point in time it represents and forms the basis of the horoscopic traditions of astrology. However, no studies have shown any scientific support for the accuracy of horoscopes, and the methods used to make interpretations are, at best, pseudo-scientific.
In common usage, horoscope often refers to an astrologer's interpretation, usually through a system of Sun sign astrology or based on calendar significance of an event, as in Chinese astrology. In particular, many newspapers and magazines carry predictive columns based on celestial influences in relation to the zodiacal placement of the Sun on the day of a person's birth, identifying the individual's Sun sign or "star sign" based on a conventional zodiac (which is not the celestial one). Such a concept is distinct from horoscopes as typically employed, where only the traditional zodiacal placement of the Sun is considered in interpretation. While this modern usage is perhaps the most popular in the colloquial lexicon, this article will focus primarily on the traditional concept.
A horoscope is a snapshot of space time or snapshot of nine planets (westerners count Uranus, Neptune and Pluto also) at the time of a persons birth. Using the horoscope chart, the events in the life time of the native can be predicted by a skilled and experienced astrologer.
In Tamil Nadu mostly thirukanitham or Lahiri method is used for ayanamsa calculation. Where as in southern parts of Tamil Nadu Vakiya panchangam is used. Vakiya is the older method to calculate planetary positions. Ancient rishis using their dhivya thristi found the formulas to calculate positions in this vakiya method. Thirukanitham uses latest scientific calculations of planet positions. In Thirunelvli pambu (snake) panchangam is used.