The sign written Imix in the colonial Yucatec sources is Imox to the ajq'ijab', the daykeepers of the K'iche' highlands who still run the count today, and the Classic-period inscriptions carry it as the first of the twenty with a glyph of its own rather than any later spelling. Reading the three together is the ordinary condition of Maya calendar study: one sequence, several languages, and a long documentary gap between the carved record and the living practice that survived it.
The 260-day count reached well beyond the Maya area. In central Mexico the same arithmetic of twenty signs against thirteen numbers ran as the tonalpohualli, and the sign standing first there is Cipactli, the crocodile or earth caiman, the same primal reptile afloat in the first waters that Imix carries. Correspondences of this kind hold along the whole list, which is the strongest single reason to think the count older than any one of the peoples who kept it.
Within the count, each of the twenty signs opens a trecena, a run of thirteen consecutively numbered days, exactly once in every 260-day round, so a trecena beginning 1 Imix exists and colours the twelve days after it. Imix is not among the four signs able to carry a year. In the Classic system those are Ik, Manik, Eb and Kaban; in the Postclassic Yucatec system Diego de Landa recorded they are Kan, Muluc, Ix and Kawak.