The Mayan Long Count is used to record dates over long periods of times. It is a permutation count, like the Calendar Round, based on the Mayan visegismal numbering system. It differs from the pure use of the Mayan mathematical system in that a count of 18, instead of 20, in the second place, gives a unit of 360 days, close to a year. The short month of 5 days is eliminated to preserve the pure cyclic nature of the count. The long count cycles are:
| 20 kins | equal | 1 uinal or 20 days |
| 18 uinals | equal | 1 tun or 360 days |
| 20 tuns | equal | 1 katun or 7,200 days |
| 20 katuns | equal | 1 baktun or 144,000 days |
Long counts inscribed on Mayan monuments consist of the cycles shown above, listed from top to bottom in descending order of length, each with a numerical coefficient specifying the number of each unit in the date. The sum of the number of days specified by this count yields the number of days passed since the beginning of the last Great Cycle. A great Cycle has a length of 13 baktuns. It is currently believed (according to the Thompson correlation) that the last Great Cycle began on 13 August 3114 BC (Gregorian calendar).
A long count of :
| 8 baktuns | or | 1,152,000 days |
| 11 katuns | or | 79,200 days |
| 15 tuns | or | 5,400 days |
| 3 uinals | or | 60 days |
| 18 kins | or | 18 days |
corresponds to 1,236,678 days since the close of the last Great Cycle. In the Calendar Round this corresponds to 5 Etznab 1 Zip. In articles where Long Count dates are given, you would see this date expressed in the shorthand notation 8.11.15.3.18. This date corresponds to Wednesday, July 9, 273 AD in the Gregorian calendar.
The Long Count was widely used in Mesoamerica in Classic and earlier times.
Return to the Table of Contents