Zodiac constellations can be traced even further back, to Bronze Age (First Babylonian dynasty) sources, including Gemini "The Twins", from MAŠ.TAB.BA.GAL.GAL "The Great Twins", and Cancer "The Crab", from AL.LUL "The Crayfish", among others. Around the end of the 5th century BC, Babylonian astronomers divided the ecliptic into twelve equal "signs", by analogy to twelve schematic months of thirty days each. Each sign contained thirty degrees of celestial longitude, thus creating the first known celestial coordinate system. Unlike modern astronomers, who place the beginning of the sign of Aries at the place of the Sun at the vernal equinox; Babylonian astronomers
Burmese zodiac as they were derived from Indian and ultimately Western zodiac. Each "yathi" is divided into 30 degrees ( ); each degree into 60 minutes ( ); and each minute into 60 seconds ( ). The zodiac month consists of 27 days, approximating the mean sidereal month of 27.321661 days. Thus each zodiac day, called "nekkhat" ( ), represents a lunar mansion, or a segment of the ecliptic along which the moon revolves around the earth. Though the names are Burmese adaptations of Sanskrit names, the Burmese system is not the same as the modern Indian system. The Burmese system uses