Through constant observation of the movement of the stars, the inhabitants of Tehuacalco were able to calculate time. This allowed them to know the length of the year and its seasons with great precision in order to determine productive activities such as agriculture and the celebration of rituals. The importance of time measurement is evident in the arrangement of marks around the visual lines of solar displacement and in the construction of the temples, since the observation of the movement of the stars was done from fixed points. The smooth stele located in the center of this complex made it possible to align the gaze with respect to the hills in the background, in order to know and record the positions of the sun at dawn throughout the year. The two structures that limit this plaza were consecrated to fire.