Convert a Gregorian Date to the Mayan Calendar
Choose a date to see its Long Count, Tzolk'in, and Haab' values.
What this Mayan calendar calculator does
This calculator converts a modern Gregorian calendar date into key Mayan calendar formats. It is useful for students, educators, history enthusiasts, and anyone curious about ancient Mesoamerican timekeeping systems.
- Long Count: A linear day count used to track very long periods of time.
- Tzolk'in: A sacred 260-day cycle combining 13 numbers and 20 day names.
- Haab': A 365-day civil cycle of 18 months of 20 days plus the 5-day Wayeb period.
A quick guide to the three Mayan date systems
1) Long Count
The Long Count is often written as five numbers separated by dots: baktun.katun.tun.uinal.kin. Each position is a base-20-like unit (with one modified step):
- 1 kin = 1 day
- 1 uinal = 20 kin
- 1 tun = 18 uinal = 360 days
- 1 katun = 20 tun = 7,200 days
- 1 baktun = 20 katun = 144,000 days
2) Tzolk'in
The Tzolk'in combines numbers 1 through 13 with a sequence of 20 day names. The two cycles rotate together to produce 260 unique day combinations. This cycle was central to ritual timing and divinatory use.
3) Haab'
The Haab' is the 365-day civil year: 18 named months of 20 days each, followed by a short 5-day period called Wayeb. The day format is usually shown as a day number plus month name.
How the conversion works
The calculator uses a standard mathematical approach:
- Convert your Gregorian date into a Julian Day Number (JDN).
- Subtract the selected correlation constant (default: 584283).
- The resulting day count is mapped into Long Count, Tzolk'in, and Haab' cycles.
Because researchers have proposed different correlation constants, two calculators can disagree if they use different values. This tool lets you adjust the constant if you want to compare approaches.
Example interpretation
A famous date is 2012-12-21. Under the GMT constant, it converts to 13.0.0.0.0 in Long Count. This marked the completion of a baktun cycle—not an apocalyptic endpoint. In other words: it was a rollover date, not the end of time.
Frequently asked questions
Did the Mayan calendar predict the end of the world?
No. Popular media often misrepresented this topic. The Mayan system tracks cyclical and linear time; completing a cycle is similar to finishing one odometer turn and starting the next.
Why is the correlation constant important?
The Mayan and Gregorian calendars are anchored by a correlation constant. Change that anchor and every converted date shifts. GMT (584283) is the common default in many academic and educational tools.
Can I use this for historical study?
Yes, for educational and exploratory work. For specialist epigraphy or archaeological research, always verify assumptions about calendar reform, regional usage, and correlation model.