The Mayan Calendar 5200-year Great Cycle is a variation of the Long Count Initial Series. Formerly developed in conjunction with the Dresden Codex, the Long Count begins with the presumed Mayan Creation date, noted as 13.0.0.0.0. The most significant digits on the left are Baktuns (400-years), next are Katuns (20-years), and Tuns (360-days), and Uinals (20-days) and Kins (days). The Long Count measures 13 consecutive 400-year-Baktun-cycles or 5200-Tun-years. Therefore, conjecture rationalizes at least 12 Baktuns and possibly 13 Baktuns have elapsed prior to the onset of the Long Count. The 5200-year Great Cycle, on the other hand, introduces a cyclic calendar system whereby 5200-Tun-years repeat to mirror the 52-year Calendar Round. The secondary age category cumulatively adds to achieve 5200-Tun-years, or as some historians agree, 5200-Haab-solar-years in a Mayan 5200-year Great Cycle. The Great Cycle is generally associated with 5200-Tun-years having 360-days each. Depending on the context used, some opinions favor the 365-day-Haab-solar-year. The special treatment of the Wayeb 5-feast days between the 360-day-Tun-year and the 365-day-Haab-solar-year is usually included for Long Count projections.

The Antediluvian Calendar system applies 13 steps of 400-year-Baktun-cycles to describe the 5200-year Great Cycle from Adam to Enoch. Six 800-year Generation Cycles extend the secondary age category to represent the lives of six Patriarchs. The six secondary ages measure time since fatherhood until the character