"the binding of our years," refers to the culminating ceremony done at the end of a 52-year cycle (see attestations)
Ie vncan, ie ipan in toxiuhmolpilia... inic otlaiaoalo nauhcampa matlacxiuitl omeey = When [came] the time of the binding of our years... thirteen-year [cycles] had four times made a circle (central Mexico, sixteenth century)
Fr. Bernardino de Sahagún, Florentine Codex: General History of the Things of New Spain; Book 7 -- The Sun, Moon, and Stars, and the Binding of the Venus, No. 14, Part VIII, 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, 1961), 25.
"...Toxiuhmolpilia, or 'the Binding of the Years,' the ceremony provides a picture of the Aztec commitment to the regeneration of the cosmos that relates astronomy, calendars, child-rearing, autosacrifice, war, and human sacrifice together."