Mayan Calendar Converter — Long Count, Tzolkin & Haab | LazyTools

Historical Calendar Tool

Mayan Calendar Converter — Long Count, Tzolkin & Haab

Convert any Gregorian date to three Mayan calendar systems simultaneously — the Long Count, the Tzolkin (260-day sacred calendar) and the Haab (365-day civil calendar). The Tzolkin shows the number (1–13), the day name and the symbolic meaning. The Haab shows the day and month name. Furthermore, the Calendar Round — the combined 52-year Tzolkin-Haab cycle — is displayed as a single date notation that ancient Maya used for dating.

Long Count + Tzolkin + HaabCalendar Round dateDay name meaningsCreation date epochGMT correlation

Gregorian date

How to use the Mayan Calendar Converter

Select any Gregorian date

Click the date field and select any date. Furthermore, the tool defaults to today — showing the current Mayan date in all three calendar systems simultaneously. The conversion works for any date from the Mayan creation date in 3114 BCE onwards.

Read the Long Count

The Long Count appears as five numbers separated by dots — baktun.katun.tun.uinal.kin. Furthermore, each position counts in a specific unit: 1 baktun = 144,000 days (approximately 394 years). The Long Count gives an absolute position in Mayan history.

Read the Tzolkin (260-day cycle)

The Tzolkin combines a number from 1 to 13 with one of 20 named days. Furthermore, the day name's symbolic meaning appears below — from Imix (primal waters) through Ahau (flower and sun). Each of the 260 Tzolkin days carries a unique energy in Mayan tradition.

Read the Haab (365-day civil calendar)

The Haab shows the day number (0–19) and month name. Furthermore, the Haab has 18 months of 20 days plus a 5-day period called Wayeb — considered unlucky by the ancient Maya. Together, the Tzolkin and Haab form the Calendar Round.

Understand the Calendar Round

The Calendar Round is the combined Tzolkin-Haab date. Furthermore, this combination repeats every 52 Haab years (18,980 days). The ancient Maya used the Calendar Round for dating events within a 52-year cycle — similar to how we use dates within a century.

The three Mayan calendar systems

The Maya used three interlocking calendar systems simultaneously. Furthermore, each served a different purpose — historical record-keeping, religious ritual and civil administration.

Calendar	Length	Purpose	Structure
Long Count	Unlimited	Historical dates — absolute position	baktun.katun.tun.uinal.kin
Tzolkin	260 days	Sacred — divination, ceremonies	13 numbers × 20 day names
Haab	365 days	Civil — agriculture, seasons	18 months × 20 days + 5-day Wayeb
Calendar Round	52 Haab years	Dating within a lifetime	Tzolkin + Haab combined position

The Long Count units

The Long Count counts days from the Mayan creation date. Furthermore, each position uses a base-20 system except the third position (tun) which uses base-18. This gives the famous "vigesimal" (base-20) counting system of the Maya. Moreover, 1 baktun equals 144,000 days — approximately 394 solar years.

How Mayan calendar conversion works

The conversion uses the GMT (Goodman-Martinez-Thompson) correlation constant of JDN 584283 — the Julian Day Number of the Mayan creation date (13 August 3114 BCE in the Gregorian proleptic calendar). Furthermore, subtracting this from the target date's JDN gives the total Long Count days since creation.

Total days = JDN − 584283 (GMT correlation constant)

kin = total_days mod 20 (0–19)
uinal = floor(total/20) mod 18 (0–17)
tun = floor(total/360) mod 20 (0–19)
Tzolkin number = (total + 3) mod 13 + 1 (1–13)
Tzolkin day = total mod 20 (one of 20 named days)

The GMT correlation debate

The GMT correlation constant 584283 is the most widely accepted mapping of Mayan Long Count dates to Julian Day Numbers. Furthermore, this was established by Goodman, Martinez and Thompson through correlation with historical records. Moreover, some researchers use the variant 584285 — differing by two days. The GMT 584283 constant matches the majority of available historical and astronomical evidence.

Worked example: 21 December 2012 — the end of the 13th Baktun

21 December 2012 was widely anticipated as significant because it marked the end of the 13th Baktun in the Mayan Long Count. What is the full Mayan date for this day?

Calendar system	Date for 21 December 2012
Long Count	13.00.00.00.00
Tzolkin	4 Ahau (Ahau = Flower/Sun, the 20th day name)
Haab	3 Kankin
Calendar Round	4 Ahau / 3 Kankin

13.00.00.00.00 marked the completion of a grand Mayan cycle — 13 baktuns of 144,000 days each = 1,872,000 days from the creation date. Furthermore, rather than an apocalypse, Mayan scholars explain this as the beginning of a new great cycle — similar to how the Gregorian calendar begins a new millennium at the year 2000. The next day was simply 0.00.00.00.01 in the 14th baktun.

What is the Mayan calendar?

The Mayan calendar is three interlocking systems developed by the ancient Maya of Mesoamerica. Furthermore, the Long Count, Tzolkin and Haab each serve different social and religious functions. All three were used simultaneously for over a millennium — often inscribed together on stone monuments.

The Long Count is a linear count of days from the Mayan creation date — 13 August 3114 BCE in the proleptic Gregorian calendar. Furthermore, it enabled the Maya to record dates across centuries — essential for their astronomical observations. Moreover, Mayan stone monuments (stelae) typically record all three calendar dates together.

The Tzolkin — the sacred calendar

The Tzolkin has 260 days — a cycle still used by Maya communities in Guatemala. Furthermore, it combines 13 numbers with 20 named days. Each Tzolkin day carries deities, symbolic meanings and ritual significance. Moreover, Maya daykeepers still use the Tzolkin for guidance and naming ceremonies in highland communities.

The Haab — the solar calendar

The Haab is an 18-month civil calendar of 365 days — close to the solar year. Furthermore, 18 months of 20 days each give 360 days plus the unlucky 5-day Wayeb. Moreover, the Haab governed agriculture, festivals and administrative cycles in Mayan society.

Why the Mayan calendar is studied today

The Mayan calendar is one of the most sophisticated independent time-keeping systems ever developed. Furthermore, Mayan astronomers tracked Venus, the Moon and Sun with exceptional precision. Moreover, the Long Count's precision enabled accurate eclipse prediction centuries in advance.

The living Maya calendar tradition continues in Guatemalan highland communities. Furthermore, Mayan daykeepers still practise the 260-day Tzolkin calendar for ceremonial guidance, naming of children and agricultural decisions. Moreover, the Mayan calendar has attracted worldwide interest — particularly around key Long Count dates like 13.00.00.00.00 on 21 December 2012.

Mayan astronomy and calendar accuracy

The Mayan Haab calendar's 365 days is close to but not equal to the solar year of 365.2422 days. Furthermore, the Maya were aware of this discrepancy — some researchers believe the Dresden Codex contains a sophisticated correction mechanism similar to modern leap years. Moreover, the Venus calendar in the Dresden Codex tracks the 584-day Venus synodic period so accurately that it required no correction for several centuries.

Frequently asked questions

What is the Mayan creation date?▼

The Mayan creation date — the starting point (0.0.0.0.0) of the Long Count — corresponds to 13 August 3114 BCE in the proleptic Gregorian calendar under the GMT correlation constant. Furthermore, this date had mythological significance for the ancient Maya as the beginning of the current world age. Moreover, the choice of correlation constant affects the conversion by up to 2 days — the GMT constant 584283 is used by most scholars and archaeologists.

Does the Mayan calendar predict anything for the future?▼

No. Mainstream archaeology and Mayan scholars agree that the Mayan Long Count simply counts days from a mythological creation date, with no inherent predictive meaning for specific dates. Furthermore, 21 December 2012 (13.00.00.00.00) marked the end of a 5,125-year cycle — interpreted by scholars as the beginning of a new cycle, not an endpoint. Moreover, the Maya recorded dates beyond 13.00.00.00.00 in their own inscriptions, confirming that they expected time to continue.

How long does the Tzolkin cycle last?▼

The Tzolkin cycle has 260 days — exactly 13 × 20. Furthermore, after 260 days, the number-day combination returns to 1 Imix and the cycle repeats. The Tzolkin's 260-day length may correspond to the human gestation period (~266 days), the agricultural cycle in Maya highlands, or the synodic period of various planets — multiple explanations have been proposed. Moreover, the Tzolkin is still in use today in Maya communities in Guatemala.

What is the Calendar Round?▼

The Calendar Round is the combined cycle of the Tzolkin (260 days) and the Haab (365 days). Furthermore, because 260 and 365 share no common factors beyond 5, the Calendar Round repeats only every 18,980 days — approximately 52 Haab years (52 × 365 = 18,980). The Maya used the Calendar Round for dating events within a human lifetime. Moreover, for dates beyond one Calendar Round, the Long Count was needed to distinguish which 52-year cycle an event occurred in.

Why does the Haab year have a month called Wayeb?▼

Wayeb is the 19th and final "month" of the Haab — a 5-day period at the end of the 18-month civil calendar. Furthermore, the Maya considered Wayeb a dangerous and unlucky transitional time — when the world was out of balance and the dead could return. Activities were restricted and purification rituals were performed during Wayeb. Moreover, at the end of Wayeb, the Haab new year began with Pop — the first month — and normal life resumed.

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