Burmese zodiac zodiac employs eight signs in a seven-day week, with each sign representing its own day, cardinal direction, planet (celestial body) and animal; it is known as the "Mahabote zodiac". The zodiacs, with slight variations, are also found in Sri Lanka and Thailand. While the eight signs are the most prevalent in modern Burmese zodiac, the zodiac officially also recognizes a ninth sign called Ketu ( ), which rules over all of the signs. The same sign also appears in Sri Lanka and Thailand under the same name. Ketu's sign is a mythical Animal of Five Beauties called pyinsarupa ( )
Zodiac and astronomer Ptolemy, whose work "Tetrabiblos" laid the basis of the Western astrological tradition. Under the Greeks, and Ptolemy in particular, the planets, Houses, and signs of the zodiac were rationalized and their function set down in a way that has changed little to the present day. Ptolemy lived in the 2nd century AD, three centuries after the discovery of the precession of the equinoxes by Hipparchus around 130 BC. Hipparchus's lost work on precession never circulated very widely until it was brought to prominence by Ptolemy, and there are few explanations of precession outside the work of Ptolemy until