The twelfth baktun in the Mesoamerican Long Count calendar begins.

Baktun

Unit of time in the ancient Maya Long Count Calendar

A baktun is 20 kʼatun cycles of the ancient Maya Long Count Calendar. It contains 144,000 days, equal to 394.26 tropical years. The Classic period of Maya civilization occurred during the 8th and 9th baktuns of the current calendrical cycle. The current baktun started on…