Mayan Calendar

The Maya Long Count tracks days from a mythic creation date using positional baktun, katun, tun, uinal, and k'in coefficients in a vigesimal (base-20) system with calendrical tweaks. Epigraphers, game designers, and cultural educators convert between Long Count notation and Gregorian dates when reading stelae transcriptions or building educational timelines—not for payroll or legal deadlines.

Long Count structure

A typical notation 9.15.6.1.9 counts baktun.katun.tun.uinal.k'in from the epoch correlation used by this site (GMT 584283 alignment common in scholarship). Each uinal is 20 k'in; each tun is 18 uinal (360 days); higher orders multiply by 20. The 18×20 tun rule is the main calendrical exception to pure base-20.

This differs entirely from Unix epoch or Julian Day Number scalars—do not mix formulas.

Correlation constants

Scholars debate slight correlation offsets (GMT vs BST). Calculators pick one correlation and stay consistent—document which anchor your textbook uses when comparing epigraphy papers. Off-by-one-day disagreements usually mean correlation mismatch, not arithmetic bugs.

For living civic dates in Mexico and Guatemala, Gregorian civil calendar remains authoritative for contracts.

Haab and Tzolk'in (context)

Long Count often appears alongside 260-day Tzolk'in and 365-day Haab round dates on monuments. This converter focuses on Long Count ↔ Gregorian; full round-calendar synthesis requires additional rings not duplicated here.

Compare cultural systems via Hebrew and Islamic converters for classroom side-by-side modules.

Worked Mayan examples

Example: decode 12.18.5.0.0 to a Gregorian date and verify against a published stela catalog entry for a 2026 museum exhibit label.

Example: encode 2026-01-01 to see Long Count coefficients for a game quest timeline — artists use results for UI glyphs, not astronomy.

Example: teach vigesimal carry—increment k'in from 19 to 0 rolls uinal, but tun uses 18 uinal carry—walk through one manual step then confirm here.

Accuracy and scope

BCE Gregorian proleptic dates appear in academic range. This is educational conversion, not endorsement of apocalyptic interpretations tied to past baktun rollovers.

French Revolutionary dates: French Republican. Roman display: Roman numeral date.

Epigraphy notation variants

Monuments abbreviate coefficients with glyph blocks; transcriptions use dotted notation with missing positions implied zero. Epigraphers align damaged stelae by matching partial Long Counts to known king lists—this converter validates complete dotted strings students enter.

Mesoamerican databases may store Long Count components in separate columns—assemble baktun.katun.tun.uinal.kin before converting.

Classroom ethics and accuracy

Teach Mayan mathematics as living Indigenous heritage, not prophecy memes. Cite scholarly correlation constants and acknowledge uncertainty where epigraphers debate offsets.

Compare vigesimal thinking with Hebrew lunisolar cycles in world history units without conflating systems.

Digital humanities metadata

When building museum APIs, store Long Count components as structured JSON plus computed Gregorian ISO for search—scholars query both. Cite correlation constant in API docs.

Games using Mayan theming should credit cultural consultants and avoid treating calendars as puzzle gimmicks disconnected from history.

Citation in academic papers

Cite the correlation constant and software version when publishing converted Long Count dates—peer reviewers expect reproducibility.

Distinguish Long Count from Aztec calendar systems in undergraduate essays.

Exhibit label workflows

Museums preparing stela replicas print Long Count and Gregorian on adjacent labels—convert here, then have epigraphy staff sign off before opening night. Interactive kiosks should cite scholarly correlation in small type so visitors understand uncertainty ranges.

Collaboration with Indigenous scholars

Consult community experts when public programs feature Mayan calendars—accuracy includes respectful framing. Software output is one scholarly correlation, not the only valid cultural perspective on timekeeping.

Video game localization

Quest text referencing Long Count should include Gregorian tooltips for players unfamiliar with Mesoamerican notation. QA scripts should flag untranslated dotted coefficients before submissions to platform holders.

Board game rulebooks

Tabletop designers referencing Long Count epochs should footnote correlation constant in rulebook appendix so competitive players can settle date disputes without forum arguments.

Typography in exhibits

Use dotted Long Count notation consistently on wall panels—mixed comma styles confuse visitors comparing stela rubbings to digital displays.

Summer camp curricula

Archaeology camps use Long Count worksheets—counselors verify answers here before awarding badges to avoid teaching wrong correlation constants.

Library cataloging

Anthropology theses indexed by Long Count need Gregorian sort keys in OPAC—dual fields prevent discovery failures when patrons search by familiar dates.

Open textbook supplements

Open educational resources on Mesoamerica should link this converter in exercise keys so self-study learners can check Long Count homework without email-ing instructors.

Documentary fact-checking

Film researchers verifying on-screen Long Count graphics should compare glyphs to converted Gregorian dates before broadcast— viewers notice mismatched season references.

Children's museum interactives

Touch-screen exhibits letting kids enter Long Count coefficients should show Gregorian results immediately— delayed conversion confuses queue lines on busy weekends.

Visitor FAQ cards

Print pocket FAQ cards listing correlation constant and example Long Count decode so docents answer common tour questions without opening laptops mid-gallery. Laminate cards near stela replicas for quick reference during peak hours.

Correlation constants in practice

When you publish a Long Count beside a Gregorian date, name the correlation constant (often 584283) in the same paragraph. Without it, readers cannot reproduce the conversion from another catalog.

Epigraphy and correlation

Mayan Long Count inscriptions use baktun cycles unrelated to 2026 Gregorian planning—museum labels should separate archaeological notation from this converter’s educational Gregorian crosswalk. GMT correlation constants differ in specialist literature; cite which correlation your homework assumes when comparing class answers.

Tour guides linking “Mayan calendar end dates” to modern fears should clarify misinterpretations of rollover notation versus apocalyptic claims—this tool supports date translation homework, not prophecy.

Compare homework answers only after agreeing which correlation constant the 2026 syllabus uses—small shifts change Long Count glyphs at the baktun level.

Museum interpretation standards

Interpretive panels should separate Long Count from pop-culture "end of calendar" myths when 2026 school groups visit—this converter supports homework crosswalks, not prophecy claims. Replica codices in gift shops should cite scholarly correlation footnotes consistent with classroom assignments.

Related tools

Converters hub cultural calendars, date tools.