Mayan calendar systems
To count the days in a year, the Maya used two counting cycles: the tzolk’in and the haab.
The tzolk’in is a cycle of 260 days, with a sequence of 20 day names divided into 13-day “weeks.” There are several theories regarding the origin of the 260-day cycle. 260 days is the agricultural growth cycle in Mesoamerica. It is also the gestation period of the human female and the interval of appearance of Venus.
The haab is a 365-day cycle similar to our solar year. It consists of 18 months of 20 days each, with a 5-day “short month” at the end, to total the 365 days of the solar cycle.
This chart shows day symbols, with several variations of the glyph for the day Ahau.
More Exhibit Items
One dot for one year; one line for five years