In this symbolic representation of the universe, space, time, and the realms of heaven and earth are integrated into one whole. The four directions are distributed around a sacred center, shown here as Xiuhtecuhlti, the god of fire. Within each quadrant, two gods in a dynamic relationship rule and characterize life. At each point of the linear design that traces a cycle around the page (and through the four quadrants) is the symbol of one of the 20 sacred named days. Additional layers and cycles of meaning are represented, such as the year bearer symbols in each corner.

All the códices in the Borgia group feature the sacred calendar year, but the Borgia Codex itself has a unique mystical sequence that has been subject to numerous interpretations over the years. Beginning with the two leaves shown, the codex literally shifts perspective by changing the orientation of the pages ninety degrees. To properly read it, the codex must be turned so that the folds between the pages lie horizontally rather than vertically. Some scholars interpret this as a depiction of a series of powerful rituals carried out in a sacred ceremonial center, and requiring entrance into another reality in order to communicate with the gods via autosacrifice and the use of hallucinatory plants. Others believe that it is a symbolic story associated with the moment when the Great Star (Venus) passes out of view, and that it is representative of the fall of the god Quetzalcóatl into the underworld. It is a striking and unusual passage among the Mesoamerican códices.

These two leaves portray the figures of Quetzalcóatl (left), the god of wind, and Mictlantecuhtli (right), the god of death. Quetzalcóatl also is associated with change, transience, the priesthood, and the founding of the culture. The two gods are positioned back to back, implying opposition or balance. Leaf 76 shows which of the sacred day signs are under the influence of which god. The day signs appear around the gods, each associated with a part of the body. The two gods share four signs; for example, the rabbit sign is situated where their backs meet. Oddly, four of the day signs are missing, possibly by design or due to faulty transcription. In reading auguries or diagnosing illnesses, the priest would decipher the meanings associated with the gods, days, and parts of the body to interpret the influences at work. Leaf 75 shows the influence of the two gods on the trecenas, the 13-day periods through which the 20 sacred days repeatedly cycle. An equal number of trecenas are under the influence of each god.

The sacred calendar and other cycles documented in the códices provided a manual through which priests could peer into the past and gaze into the future, informed by ever repeating and layered patterns. The Laud, displayed upright in circular form, records the cycle of ceremonies through the count of days.