The Mayan Long Count is a calendar consisting of 5 cycles that indicate the number of days since the last beginning of the full cycle. The name, definition, and length of each cycle is indicated in the following table.
Name Definition Length k'in = 1 day 1 day winal = 20 k'in 20 days tun = 18 winal 360 days k'atun = 20 tun 7,200 days = about 20 years b'ak'tun = 20 k'atun 144,000 days = about 394 years (full cycle) = 20 b'ak'tun 2,880,000 days = about 7885 years
a particular date in the Long Count is written as a set of five numbers, one for each subcycle, separated by periods (.). For example, the date 18.104.22.168.5 means 1 b’ak’tun, 2 k’atun, 3 tun, 4 winal, 5 k’in after the beginning of the full cycle. The beginning of the last cycle, at long count 0.0.0.0.0, is thought to correspond to 6 September -3113 C.E.
The Long Count 22.214.171.124.0 corresponds to 21 December 2012 C.E., and the
current full cycle will be complete on 13 October 4772 C.E. The
calendar function can return, in text form, the Long Count
corresponding to any date.
For the Mayan Haab’ and Tzolk’in calendars, see Mayan Tikal Calendar.
Further reading: The Book of the Year: Middle American Calendrical Systems, by Munro. S. Edmonson; University of Utah Press, 1988.