European Dates

For those who do not wish to read this section beyond this first paragraph, please note that in this Who's Who in the Classic Maya World, I shall list European dates in the Julian Calendar, using the most popular correlation between the Maya and European calendars. For those who would like to read further, I shall attempt a potted history of what I am calling here the European calendar and its correlation with that of the Maya.

The correlation between the Maya and European calendars is still not universally agreed upon, but most scholars accept a correlation in the so-called 'GMT' family of correlations. In this context, GMT has nothing to do with Greenwich Mean Time, but rather with Joseph Goodman (1905), Juan Martínez Hernández (1928), and J. Eric S. Thompson (1927), who independently came up with a proposed correlation that places the beginning of the current Maya era in the year 3114 BC. Goodman proposed a correlation that has the beginning date of the current Maya era as 3 September in the Julian Calendar, or 8 August in the Gregorian Calendar. Martínez Hernández proposed a correlation that was one day later (4 September Julian or 9 August Gregorian), and Thompson originally proposed one that was four days after that, on 8 September, 3114 BC (Julian) or 13 August, 3114 BC (Gregorian). Thompson later revised his correlation earlier by two days, but his original correlation is the one most commonly favored today.

Actually, this is only part of the answer, since-contrary to popular belief-the so-called European calendar is far more complicated than that of the Maya. For one thing, there are in fact three different ways of calculating the days in European calendars. One of them was devised by a calendar advisor to Julius Caesar (not the advisor who told him to beware the Ides of March, apparently). In 45 BC this advisor, Sosigenes, suggested a correction to the previous Roman calendar, by adding one extra day every four years (this involved the year 46 BC-the "Year of Confusion"-having 445 days!). This calendar remained in effect in western Europe until at least 1582, when Pope Gregory XIII decreed that even century-ending years not divisible by four (are you still with me?) would not be leap-years, even though by Sosigenes' rule they would have been. In other words, AD 1600 and 2000 would be leap-years, but 1700, 1800, and 1900 would not. The true length of the solar year is 365.2422 days. The Roman calendar before Caesar and Sosigenes had years of 365.0000 days, and with Sosigenes' reform the length changed to 365.2500 days. With Pope Gregory's reform, the length of the solar year changed to 365.2425 days, which means that the 'seasons' get out of step by one day in 3,333 years (I am indebted to Anthony Aveni [1990:114-118] for the details of this calendar history). Roman Catholic European countries adopted the Gregorian calendar in 1582 (the month of October, 1582, skipped from the 4th to the 15th); Great Britain and her colonies did not change until 1752.

The problem with all this for our purposes is: which calendar do we use for translating Classic Maya dates? In fact both Julian and Gregorian dates have been used in different studies, which has led to great confusion in the literature (especially when combined with different correlations within the 'GMT' family).

The other 'western' calendar is one used for astronomical computations. Just to confuse the issue even more, this is called the Julian era, or Julian Day count. This was calculated to have begun on 1 January, 4713 BC., and each day simply has a number which represents how many days had elapsed since the beginning of the era. In Thompson's original correlation (the one now most favoured by Mayanist scholars), the Julian Day (JD) number of the beginning point in the Maya calendar (are you sure you're still with me?) is 584,285 (this number is called the 'correlation constant'). In other words, 13.0.0.0.0 4 Ajaw 8 Kumk'u, 8 September, 3114 BC (Julian) and 13 August, 3114 BC (Gregorian), is 584,285 days into the Julian era, JD 1 having been 1 January, 4713 BC, over half a million days earlier.

There is one other twist: astronomers, who still use the JD calendar, do not use 'BC' and 'AD', but rather 'minus' and 'plus' years, with a year '0' in between. Year '1' equals AD 1, but this means that Year 0 equals 1 BC, and 4713 BC equals -4712. Concerning the Maya calendar, this means that the beginning of the current Maya era, 3114 BC, equals -3113 in astronomers' years. Unfortunately, many publications have confused these two, and have incorrectly talked about 3113 BC. Ironically, Thompson himself has contributed to this error (Thompson 1972:24), which has remained remarkably durable in the literature.

I could go on, but I'm sure you've all had quite enough. So I'll end this essay by repeating that I shall use the 584,285 'correlation constant' in this Who's Who in the Classic Maya World, and I shall list European dates in the Julian Calendar.

Reference