The tonalpohualli ("count of days") is the sacred 260-day calendar of the Aztecs, the same count the Maya call the tzolk'in. Two wheels turn together: a wheel of 13 numbers and a wheel of 20 day signs — Crocodile, Wind, House, Lizard, Serpent, and so on to Flower. Their combinations repeat only after 13 × 20 = 260 days, and every combination names one unique sacred day, such as 4 Ollin or 10 Xochitl. The day you were born is your tonalli — your day-soul — and in Aztec belief it shapes your character, your fortune, and even the work you are suited for; priests called tonalpouhque read it for every newborn from the painted books.

Each day also belongs to a trecena, a 13-day "week" coloured by its opening day and patron deity, and is watched over by one of the 9 Lords of the Night (Yohualteuctin) — from Xiuhtecuhtli, the fire lord, to Tlaloc, the rain god — who rule the dark hours in an endless cycle of nine. The day sign speaks of your outer nature, the trecena of the current beneath your days, and the Lord of the Night of the hidden gifts you carry from the hours of darkness.

What this finder shows

• Your day sign and number (e.g. 10 Xochitl), with its Maya equivalent, patron deity, and world-direction
• Your Lord of the Night and what his or her rulership means for you
• Your trecena, your day within it, and the meaning of your number from 1 to 13

Dates are converted with the standard scholarly (Alfonso Caso) correlation, anchored to the fall of Tenochtitlan on the day 1 Coatl in 1521, so the count matches the major academic references. Enter any birth date from 1600 to 2199 — and if you enjoy comparing traditions, read your tonalli alongside your Vedic janma nakshatra with a qualified astrologer.