THE CORRELATION CONSTANT

 We need to briefly gloss over the "Correlation Problem", also named the "Ahaw Equation"; I have stated above that 9.0.19.2.4  2 Kan 2 Yax is October 16, 454 A.D. Gregorian (regressed; recall that Pope Gregory XIII decreed, during his reign, that the day following Thursday October 4 1582, would be Friday October 14 1582 (Teeple, 1930, p99); this had for intent the restoration of the Spring Equinox to March 21, which had by then slipped to March 11 under the less accurate Julian Leap Year system; actually, it's more complex than this: First Point of Aries, the Spring Equinox, had slipped by a full 14 days under the Julian Calendar; only 10 days were restored AND Spring Equinox was moved from its then March 25 position to the new March 21 position!!). This date, October 16, 454 A.D. for 9.0.19.2.4 is true under the "Correlation Constant" 584285; this means that this date assumes that the Maya Creation Date, August 13 3114 B.C. Gregorian, Zero Day, occurred on the 584285th day after day 0, J.D.N., 12 o'clock noon (the astronomer's Julian Day Number).

 Don't confuse the Julian Day Number with the Julian Date! The JULIAN DAY NUMBER System, "J.D.N.", established by Joseph Justus Scaliger in the 16th Century, and possibly named in honor of his father, Julius Scaliger, begins at Greenwich, at 12 o'clock noon, on January 1, 4713 B.C., Julian, (January 1, 4712 B.C., Julian, with a year "zero" (Aveni, 1985, p204); it is based on the multiple of a 28-year Solar Cycle (every 28 years, the same day of the week will reoccur on specific date), a 19-year Lunar Cycle, and a 15-year Civil Roman Indictment/Tax Cycle (Moyer, 1981). In converting back and forth between Maya dates and Gregorian dates, Mayanists typically use the Astronomical J. D. N. as an intermediary, and so do computer conversion programs such as Marc and John Harris's "Maya3, a Mayan Calendrics Program (v3.00.01-Nov 10 1992)".

The controversy lies in that numerous conversion constants have been proposed, some differing from others by hundred of years. The correct correlation constant should fit most if not all available Maya documentation, including the Maya's astronomical observations of the Moon, planetary events such as Venus Heliacal Risings and Settings, conjunctions of Sun, Moon and Planets, Lunar Glyphs in the calendrics, historical dates of the Spanish Conquest in Mexico , Guatemala, Belize and Honduras in the 15th and 16th Century, and even the dates of today's living Maya who still use the same calendar; the correct correlation constant MUST place the Moon Age within 2 or 3 days of the calculated value, because the Moon Age was an Observational Record (Schele notes that when the Maya attempted to calculate Moon Ages rather than to observe them, they typically did not do very well; since the example of Yaxchilán Lintel 21 describes an ancestral event which occurred on 9.0.19.2.4 - 16 October 454 A.D., and was actually "written in stone" around 9.16.1.0.9, or around 12 May 752 A.D., the lunar data was not observed data, but rather calculated data; the 298 years difference between these two dates makes the lunar data on the lintel questionable as to its validity! Coe (Coe, 1992, p132), quotes Teeple as stating that Copán astronomers used a formula where 149 lunations equaled 4,400 days .. this works out to be 29.53020 days per lunation, barely 33 seconds off from modern calculations; this would compound to less than two days over a period of 298 years! Aveni notes that Palenque used an equation that gave 81 lunations = 12.4.0 days; this is an average lunation of 29.53086, or within 1 thousand of 1 percent of the modern value (Aveni, 1980, p169)).

The Copán Formula assigns "24 E/D, 6 C" to Day Zero 13 August 3114 B.C., that is the 24th day of the 6th Lunation, and the Palenque Formula assigns "22 E/D, 6C", that is, the 22nd Day of the 6th Lunation (Linden 1986, p122); you'll need to read below on the meaning of E/D and C. This demonstrates that even a stone age culture can obtain near-computer accuracy simply by keeping good stone age records, such as pebbles in a basket, if the observation time is long enough. Many correlation constants based on scholarly research have been proposed; some correlation constants which have received acceptance and followers include Makesom (489138), Spinden (489384) and Goodman-Martinez-Thompson "GMT" (584283 and 584280 to 584286); today's acceptance is generally on the Modified-Thompson-2 constant of 584285. Teeple says (Teeple, 1925, p547) that any correlation constant must account for a new moon on 9.16.4.10.7, or 9.16.4.10.8, and an ecliptic conjunction as attested by Copan Stela M and Quiriguá Stela J, and by Stela M which shows a moon group ending on 9.16.4.10.7 11 Manik. See Table 1, below, for a summary of these dates in various modes.

TABLE 1: Expressing same days in time with various calendars in various modes.

TABLE 2: Some Maya Long Count Dates, converted to Gregorian Dates, using the 584285 Correlation Constant.