The Mayans had 3 calendars. The first was the Tzolkin, or sacred calendar. The second was the Haab, or solar calendar. The third was the Long Count calendar. The Tzolkin was a 260 day calendar used by priests to determine auspicious days. The Haab had 365 days, broken down into 18 months of 20 days each, followed by 5 unlucky days. The Long Count calendar was effectively the Haab, but without the 5 unlucky days, and was used for long term recording. (http://bit.ly/39WZfjE)