2431-12-20 is part of the Coto calendar, a solar-based lunisolar calendar used by the Huastec people. It has six months, with two weeks in each month, and each month consisting of 30 days. 2431-12-20 is the 20th day of the 12th month in 2431 C.E. This day is known as Katuys, meaning "All". On this day, the Huastec people give thanks to all of their ancestors, friends, and supporters, and celebrate their many blessings.