Aztec and Maya Calendar
In the tonalpohualli, the sacred Aztec calendar, Thursday December 18, 1980 is:
Xihuitl:
solar year
8 - Calli (house)
Xiuhpohualli:
365-day calendar
6 - Tozoztontli (III)
Long Count:
Mayan calendar
12.18.7.9.9
(Correlation: Alfonso Caso - Nicholson's veintena alignment [adjust])
The significance of this day
Day Atl (Water, known as Muluc in Maya) is governed by Xiuhtecuhtli, God of Fire, as its provider of tonalli (Shadow Soul) life energy. Atl is a day for purification by subjecting oneself to the ordeal of conflict. It is a good day for battle, a bad day for rest. Water brings out the scorpion, who must sting its enemies or else sting itself. Atl is the day of the holy war, which is always a battle with one's own enemies within.
The thirteen day period (trecena) that starts with day 1-Ollin (Movement) is ruled by Tlazolteotl. This trecena is governed by the goddess of cotton and weaving, of sexuality and childbirth, she who is the eater of sins: it is the sign of the Scavenger, who feeds not on power but on the ills that darken the heart. The rainbow serpent, symbol of pleasure and folly, levitates amidst a shroud of smoke and shadow: these are 13 days of stolen secrets and odd twists of fate. The earth itself shakes: the ills created by shock can sometimes only be cured by greater shock. These are good days for self-purification; bad days for self-gratification.
Beyonce Knowles was born on day 13-Atl.
Aztec facts
The Aztecs did not use a leap year correction but they knew the length of a solar year is neither 365 nor 365.25 days. Presumably they kept some count of days to register astronomical events but no evidence of an Aztec Long Count exists.