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 used to determine the boundaries of astronomical constellations that lie in the vicinity of the zodiac, which are, and always have been, irregular in their size and shape. The convention of measuring celestial longitude within individual signs was still being used in the mid-19th century, but modern astronomy now numbers degrees of celestial longitude from 0° to 360°, rather than 0° to 30° within each sign. The use of the zodiac as a means to determine astronomical measurement remained the main method for defining celestial positions by Western astronomers until the Renaissance, at which time preference moved to the equatorial