Sources & method
This reference tries to be explicit about how confident anyone can be in each claim it makes. That means labelling claims by their evidentiary basis, and being clear about what the calculators here do and do not reconstruct.
The evidence tiers
| Tier | Means |
|---|---|
| Primary inscription | Directly attested in Classic-period monumental or codical texts / iconography. |
| Colonial source | Recorded in a 16th–18th century source — Landa's Relación, the Books of Chilam Balam, colonial dictionaries. Close to the tradition, but post-conquest and Yucatec-weighted. |
| Scholarly reconstruction | A reading or model built by epigraphers / archaeoastronomers from patterns in the corpus. Well-founded but revisable. |
| Speculative | Argued by some specialists, not broadly settled, or dependent on indirect inference. |
| Modern interpretation | 20th–21st century day-keeping practice or popular / New Age glossing. Hidden by default in the day-sign reference. The Dreamspell page is entirely this tier. |
Fixing the Maya count to our calendar
Every date on this site uses the GMT correlation, constant 584283 (Goodman–Martínez–Thompson, "584283" variant) — the value most consistent with the Classic inscriptional record, the Dresden Venus table, ethnographic day-counts, and radiocarbon dates. It places 0.0.0.0.0 at 11 August 3114 BCE (proleptic Gregorian) and 13.0.0.0.0 at 21 December 2012.
The nearby 584285 ("Lounsbury") variant shifts everything two days and also has support. Older correlations (Spinden, +489384; the "Böhm" family) differ by centuries and are not used here. A wrong correlation moves Gregorian equivalents but leaves the internal Tzolk'in / Haab' / Long Count relationships untouched.
What the calculators here do not claim
- Lord of the Night (Glyph G). The 9-night sequence is reconstructed; this site aligns it to G9 at the era-base by convention. Specialists debate the phasing.
- 819-day count. Anchored to the era-base for illustration. Individual inscriptions state their own station; a universal anchor is a modelling choice.
- Lunar Supplementary Series. Shown as a modern astronomical approximation of moon age and lunation, not a reconstruction of the specific value a Classic scribe would have carved, which followed regional lunar tables.
- Year bearers. The Tikal and Yucatec sets are both real; which "New Year station" a given site used is not always known.
- Proleptic dates. Gregorian dates before 1582 are proleptic — a back-projection, not a calendar anyone used at the time.
- Day-sign glyphs. The small square icons in the day-sign reference are abstract placeholders, not reproductions of the carved signs.
Working bibliography
Calendar & epigraphy
- Coe, M. & Van Stone, M. — Reading the Maya Glyphs.
- Stuart, D. — The Order of Days: The Maya World and the Truth About 2012.
- Thompson, J. E. S. — Maya Hieroglyphic Writing: An Introduction.
- Bricker, H. & Bricker, V. — Astronomy in the Maya Codices.
- Aveni, A. — Skywatchers (rev. ed. of Skywatchers of Ancient Mexico).
Living tradition
- Tedlock, B. — Time and the Highland Maya.
- Oxlajuj Ajpop and Maya day-keeper organisations — public statements on the 260-day count and its distinction from the Dreamspell.
Colonial sources
- Landa, Diego de — Relación de las cosas de Yucatán (Tozzer translation/edition).
- Roys, R. (trans.) — The Book of Chilam Balam of Chumayel.
The Dreamspell (for the modern-system page)
- Argüelles, J. — The Mayan Factor; Dreamspell: The Journey of Timeship Earth 2013.
- Critical discussion: Whitesides & Hoopes and others on the "Maya 2012" phenomenon and the Dreamspell's relationship to Maya tradition.
Titles are given for orientation; consult current editions and the primary corpus (e.g. the Maya Hieroglyphic Database, CMHI) for specifics.