uinal

Uinal, sometimes spelled winal, is a calendrical unit used in Maya chronology. It denotes a 20-day period. In the Maya Long Count, time is counted in kin (days), uinal (20 days), tun (18 uinal or 360 days), followed by katun and baktun.

In the Haab’ solar calendar, a uinal is the 20-day month. The Haab’ year consists of 18 uinal months of 20 days each, plus a 5-day period called Wayeb’. The 18 Haab’ uinal months carry specific names in various sources, such as Pop, Uo, Zip, Zotz, and others, reflecting the cyclical nature of the year.

Etymology and usage: the term uinal derives from the Mayan word uwinal (also written winal). In the Long Count notation, the uinal position ranges from 0 to 17 because 18 uinals constitute a tun (360 days). Therefore, while kin counts days, the uinal position tracks the 20-day-month cycles within each tun.

Significance: the uinal is a fundamental unit in Maya calendrics, linking the 20-day modular system to the larger tun-based structure. It serves as the practical unit for representing dates in both the Long Count and the Haab’ calendars, and it helps bridge Maya timekeeping with the modern calendar through scholarly conversion and interpretation.