Using the Long Count Calendar, the Maya also recorded vast amounts of time. The Long Count Calendar is based on a 360 day year (18 winals) called a tun. Twenty tuns make a K'atun (7200 days) and twenty K'atuns make a b'ak'tun (144,000 days). Thirteen b'ak'tuns make a Great Cycle, which western astrologers refer to as the precession of the equinoxes or Great Year. For example, when the equinox was in Taurus, there were many bull cults. When it moved into Aries, hero myths like the story of Marduk ‘slaying the bull’ proliferated and Aries type enlightenment/self organizing philosophies of Buddha, Greeks and Lao Tzu arose. When it moved into Pisces, fish symbolism was prevalent. As the equinox moves into Aquarius, many people are celebrating the beneficial uses of technology to bring humanity together – both Aquarian ideals.
All of these calendars systems ran together so a certain day would have several names, its tzolkin, and Haab name seated in the ‘month.’ The cycles would only start again every 52 years, a Mayan 'century.
After thirteen cycles of the twenty day names, and twenty cycles of the thirteen periods, exactly 260 days have elapsed and the interplay of thirteen and twenty begin again. Called the trecena by the Spanish, the tzolkin calendar runs from 1 through 13, then returns to the number 1 again. Each time the number 1 recurs, it will do so on a different day-sign.
The solar year and 260-day tzolkin were then interwoven into 20 year cycles called katuns. The Maya name for a day was k'in. Twenty of these k'ins are known as a winal or uinal. Eighteen winals make one tun.
The tzolkin 20 year cycles extend through a 5,125 year span of the Long Count calendar. Twenty b'ak'tuns cover 7,885 solar years. Since the Mayan calendar is cyclical and not linear – the end of the 13th b’ak’tun will start the beginning of another cycle. December 21, 2012 is simply the day that the calendar will go to the next b’ak’tun.