The fourteenth sign is Ix in Yucatec and I'x in K'iche', the jaguar, and it is among the most heavily attested day names in the Classic inscriptions, where jaguar imagery is bound up with rulership, with the night sun passing through the underworld, and with the sorcerer's animal counterpart.
Central Mexico places Ocelotl, jaguar, in the same position, so the correspondence is exact. The jaguar is one of the very few images that carries the same weight everywhere in Mesoamerica, and the day sign is only one of its appearances; it is also a throne, a title and a military order.
Ix is a Year Bearer in the Postclassic Yucatec system, where the four days permitted to open a Haab year are Kan, Muluc, Ix and Kawak. It is not one of the Classic four, Ik, Manik, Eb and Kaban, nor of the four the highland Guatemalan daykeepers use. Highland practice associates I'x with the earth and with the mountain shrines, a reading that keeps the sign in current ceremonial use rather than confining it to the inscriptions, and the atlas records it as description of a living tradition rather than as instruction.
Jaguar days are among the best documented in the Postclassic Yucatec record because Ix is a bearer there, and a year opened by Ix is named for it in the colonial sources. That gives the sign a double presence, once every twenty days as an ordinary day and once in the name of a whole year, and the two uses are distinguished in the sources by context rather than by any difference in how the sign is written.