Some readers may be interested in a brief passage by historian Francesca Rochberg on the pre-Hellenistic use of twelfth-parts by Babylonian astrologers which dated back to at least the 5th century BCE.
In the passage she notes that the Babylonians were using the twelfth-parts of the zodiac in the context of their omen lore, hundreds of years prior to the advent of Hellenistic astrology. They came to be considered an important division of the signs by numerous notable Hellenistic astrologers as well (click for an introduction to the use of twelfth-parts).
You can read the entire section on twelfth-parts in Google Books by following the link below:
Those unfamiliar with Rochberg may be interested in U.C. Berkeley’s introductory interview with her which can be read here: