# Mayan calendar

• a sacred calendar, called tzolkin
• a civil calendar, called haab
• long count, which was used for inscriptions.

## Tzolkin or sacred calendar

The sacred year consisted of 20 “months” of 13 days each. Each of the 13 days and each of the 20 “months” has a name. Both the “months” and days cycle continuously; each new day is in a new “month.” It is as if, in the Gregorian calendar, 6 January was followed by 7 February followed by 8 March. Since 13 and 20 have no common factor, there are 260 unique names for days, and the sacred year is 260 days long.

Since a date in the sacred calendar has no year component, it is not possible to convert a date like “5 Ix” to (for example) the Gregorian calendar. However, it is possible to find what the Tzolkin name for a date in the Gregorian calendar would be:

Gregorian date:

would be

## Haab or secular calendar

In the secular calendar, a year consisted of 18 uinals, which is a period of 20 days. 18 × 20 = 360 days, with five days left over, an annual unlucky period called Uayeb. The first day of the uinal was 0, and the last was 19, followed by day 0 of the next uinal.

Like the sacred calendar, it is not possible to convert a date like “5 Kankin” to, for example, the Gregorian calendar, since it has no year component.

It was usual to give both the sacred and civil name for a day.  A day thus described will not recur for 52 civil years, or 73 sacred years.

## The long count

The long count was used for inscriptions.  It is a count of the number of days since the beginning of the current period.

 alantun kinchiltun 20 calabtun 20 400 pictun 20 400 8,000 baktun 20 400 8,000 160,000 katun 20 400 8,000 160,000 3,200,000 tun 20 400 8,000 160,000 3,200,000 64,000,000 uinal 18 360 7,200 144,000 2,880,000 57,600,000 1,152,000,000 kin (sun) 20 360 7,200 144,000 2,880,000 57,600,000 1,152,000,000 23,040,000,000 1day 30days 360days about19.7Greg.years about395Greg.years about7,885Gregorianyears about157,703Gregorianyears about3,154,069Gregorianyears about63,081,377Gregorianyears

Today historians write dates in the long count in the following form (the date given is the beginning of the present era): 13. 0. 0. 0. 0. 4 Ahau, that is baktun. katun. tun. uinal. kin., followed by the name of the day in the sacred calendar.

Using astronomical events recorded both by Mayan and European astronomers, and historical events whose dates were recorded both by Spaniards and civilizations using the Mayan calendar, scholars have sought to correlate the Mayan and Gregorian calendars. According to the most widely accepted correlation (the “Goodman-Martinez-Thompson Correlation”) the current Mayan epoch began on Wednesday 11 August 3113 bce (Gregorian) which is Julian date 584,282.5.