How Many Days Is a Mayan Month?

A standard Mayan month, known as a uinal, consists of 20 days. However, the Mayan civil calendar also included a shorter period of 5 days at the end of its annual cycle.

The ancient Maya civilization developed a sophisticated calendrical system, most notably the Haab' or civil calendar, which was based on a 365-day year. This calendar was meticulously structured to align with agricultural cycles and daily life.

The Structure of the Mayan 365-Day Calendar (Haab')

The 365-day year of the Haab' calendar was primarily organized into two types of periods that can be considered "months":

1. The Uinal (Named Months)

The most common "month" in the Mayan system was the uinal.

• There were 18 named uinals in a complete 365-day cycle.
• Each uinal was precisely 20 days long.
• These months had specific names, similar to how modern calendars name months like January or February.
• The sum of these 18 months accounts for 360 days (18 months × 20 days/month = 360 days).

2. The Wayeb (Nameless Days)

To complete the 365-day year, the Maya included a special, shorter period at the end: the Wayeb.

• This was a unique period of 5 days.
• These days were considered "nameless" and held significant spiritual importance.
• They were viewed as extremely unlucky and dangerous, leading the Maya to observe them with specific rituals, including fasting and making sacrifices to their deities, to ward off misfortune.

The combination of the 18 uinal months and the 5-day Wayeb period precisely completed the 365-day civil year, vital for tracking agricultural seasons and ceremonial cycles.

Mayan Month Overview

To summarize the structure of the Mayan 365-day year:

For more detailed information on the Mayan calendar and its complexities, you can refer to resources like Britannica's article on the topic.