 Tlahuizcalpantecuhtli is one of the thirteen Lords of the Day, representing the 12th day of the Aztec trecena.Tlahuizcalpantecuhtli plays a significant role in the creation of Tonatiuh, the Fifth Sun in the Aztec creation narrative.Motolinía's "Memoriales", and the Codex Chimalpopoca relate that the Toltec ruler Topiltzin Quetzalcoatl became the morning star when he died.