A calendar of world repute, the Mayan Calendar is one of the best accomplishments to have been made by the ancient people. It is noted for its impressive accuracy and intricacy. The calendar features three dating systems, namely: the Long Count, Tzolkin (divine calendar) and Haab (civil calendar). The Haab is the only one of these three that is directly related to the length of the regular year.
The ancient Pyramid of Kukulcan at Chichen Itza in Yucatan, Mexico can be found on the right side. This ancient pyramid was said to have been constructed around 1050 when Tula's Toltecs were holding sway in political affairs during the late Mayan period. The Pyramid of Kukulcan served as the calendar. It featured a platform at the apex and four stairways, each of which has 91 steps -- totaling 365, which is the number of days you will see in a regular calendar year.
This is an example of a Mayan date: 12.18.16.2.6, 3 Cimi 4 Zotz. The Long Count date is 12.18.16.2.6; Tzolkin date is 3 Cimi and Haab date is 4 Zotz.
Several other Mesoamerican nations such as the Aztecs and Toltecs also adopted the Mayan Calendar. However, these usually made some modifications. They altered the names of days in the week and months, while leaving the working of the calendar unchanged.