The first tablet is a map made of lists. It opens with the stars of the three paths, the northern path of Enlil, the equatorial band of Anu and the southern path of Ea, some sixty six stars and constellations assigned each to its road across the sky, with the Plough, the Old Man, the True Shepherd of Anu, the Bull of Heaven and the rest of the Babylonian sky-figures in their places, many of them ancestors of the constellations still in use.
There follow the dates, month by month in the ideal calendar, on which stars first rise from the sun's glare, the pairs that rise as others set, the intervals in days between risings, and the stars the moon touches in its monthly course, the ziqpu stars that culminate overhead completing the toolkit. The second tablet turns to the wanderers and the calendar: the paths of the sun and the five planets through the same star-roads, the lengths of planetary visibility and invisibility, the solstices and equinoxes fixed in the ideal year, shadow-length tables for the hours of the day, water-clock weights for the watches of the night, and the rules for declaring an intercalary month when star-risings show the lunar year drifting against the seasons. Appended omens tie the whole to the diviner's craft. The scheme idealises, its year an even 360 days for calculation, and that very idealisation shows the compilers reaching past observation toward model-making.