Maya Calendar Converter
Enter a Gregorian date to convert it into the Maya Long Count, Tzolkʼin, and Haabʼ systems.
What this calendar maya calculator does
This tool converts a modern Gregorian date into three key Maya calendar expressions: Long Count, Tzolkʼin, and Haabʼ. It is useful for students, history enthusiasts, and anyone curious about Mesoamerican timekeeping.
The calculator uses a standard correlation constant (GMT 584283) by default, which is the most commonly used bridge between Gregorian dates and Maya inscriptions. You can adjust this constant if you want to test alternative scholarly models.
How the Maya calendar works
1) Long Count (linear day count)
The Long Count records the number of days elapsed since a mythic base date. It is written as: baktun.katun.tun.uinal.kin.
- 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) Tzolkʼin (260-day sacred cycle)
The Tzolkʼin combines numbers 1–13 with 20 day names. Every day receives one number and one name (for example, 4 Ajaw). This sequence cycles every 260 days.
3) Haabʼ (365-day civil cycle)
The Haabʼ consists of 18 months of 20 days (360 total), plus a 5-day period called Wayebʼ. A Haabʼ date is shown as day number + month name (for example, 8 Kumkʼu).
Calculation method used in this page
The converter performs four steps:
- Convert the Gregorian date to a Julian Day Number (JDN).
- Subtract the chosen correlation constant (default 584283) to get elapsed days since Maya base date.
- Break elapsed days into Long Count units.
- Apply modular arithmetic to derive Tzolkʼin and Haabʼ positions.
Because all three outputs come from the same day count, the result is internally consistent and easy to verify.
Example interpretation
If you test 2012-12-21 with the default constant, you should get 13.0.0.0.0, with Tzolkʼin and Haabʼ values commonly cited in research and popular media. This date became famous because it completed a major Long Count cycle, not because it marked an end of time.
Why a correlation constant matters
Ancient calendars are interpreted through epigraphy, astronomy, and archaeology. Different scholars have proposed different constants for mapping Maya dates to modern dates. The GMT value is the most widely accepted, so it is used here by default.
If your source uses another value, simply replace the number in the calculator and recalculate.
Practical uses
- Learning and teaching Maya chronology
- Checking historical conversion tables
- Comparing epigraphic interpretations
- Building your own timeline or study notes
Limitations and notes
- This calculator assumes the proleptic Gregorian calendar for input dates.
- It is a computational tool, not a substitute for full archaeological context.
- Name spellings vary across sources (e.g., Ajaw/Ahau, Kumkʼu/Cumku).
Final thoughts
The Maya calendar is one of the most elegant timekeeping systems in human history. By converting familiar dates into Long Count, Tzolkʼin, and Haabʼ forms, you can see time through a very different cultural lens—structured, cyclical, and deeply symbolic.