Each page of a tonalamatl represented one trecena, and was adorned with a painting of that trecena's reigning deity and decorated with the 13 day-signs and 13 other glyphs. These day-signs and glyphs were used to cast horoscopes and discern the future.
A tonalamatl page corresponded to each trecena, featuring a painting of its reigning deity. This page included the 13 day-signs and 13 other glyphs that were employed for astrological readings and fortune-telling.