See an image that represents Tititl in the Visual Lexicon of Aztec Hieroglyphs, ed. Stephanie Wood (Eugene, Ore.: Wired Humanities, 2020-present).
18 Enero. Tititl = 18 January. Tititl. (central Mexico, early seventeenth century)
Codex Chimalpahin: Society and Politics in Mexico Tenochtitlan, Tlatelolco, Culhuacan, and Other Nahuatl Altepetl in Central Mexico; The Nahuatl and Spanish Annals and Accounts Collected and Recorded by don Domingo de San Antón Muñón Chimalpahin Quauhtlehuanitzin, eds. and transl. Arthur J. O. Anderson and Susan Schroeder (Norman: University of Oklahoma Press, 1997), vol. 2, 120–121.
This feast was an observation of Ilama tecutli. The person imitating her (ixiptla) wore a white skirt (cueitl) and a white shift (huipilli). Over this she wore a star skirt (citlalli icue) with small seashells that jingled. Her sandals had white toes, woven with cotton threads. She had a shield (chimalli) covered with white clay and pasted over with eagle feathers and heron feathers, and in her other hand she held a weaving stick (tzotzopaztli).
Fr. Bernardino de Sahagún, Florentine Codex: General History of the Things of New Spain; Book 2 -- The Ceremonies, no. 14, Part III, eds. and transl. Arthur J. O. Anderson and Charles E. Dibble (Santa Fe and Salt Lake City: School of American Research and the University of Utah, 1951), 143.
ma tunpehuaca oquic CualCan [ca hueca yn Tititl = Let's get started while it is still a good time, late in Tititl. [Footnote: One of the twenty-day months of the Aztec calendar, used here as an equivalend for December. This term is from Paso y Troncoso (1902, 86); it is likely that the missing passage in the later text from Metepec had diciembre instead.](Metepec, Valley of Toluca, 1717)
In Citlalmachiyotl, The Star Sign: A Colonial Nahua Drama of the Three Kings, eds. Justyna Olko and John Sullivan, translation by Louise M. Burkhart (Warsaw: University of Warsaw, Faculty of "Artes Liberales", 2017), 18, 72.